PHOTOCURABLE BIOINK FOR INKJET 3D PHARMING

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application Ser. No. 62/681 ,396 entitled“Photocurable Bioink for Inkjet 3d Pharming,” filed June 6, 2018, which is herein incorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] The invention is generally directed to pharmaceutical tablets, and more specifically to photocurable bioink for tablet printing and methods thereof.

BACKGROUND

[0003] Drug dosages are currently determined through clinical trials, where the dosage with the best therapeutic outcome for most of the patient population is approved, however, this approach fails to account for patient-to-patient differences in drug metabolism and response. Personalized medicine has emerged with a goal to provide patients with tailored treatments that is informed by each individual’s genetic, clinical, microbiometric, and environmental information. In addition to further developments in genomics and computational biology, novel technologies and strategies are required for the manufacturing and dispensing of customized dosage forms necessary to help make personalized medicine a reality. 3D Pharming, the use of 3D printing and 2D material deposition technologies to directly fabricate personalized pharmaceutical tablets, is an attractive strategy for manufacturing personalized oral dosage forms. Specifically, this technology allows for the custom design of pharmaceutical tablets containing personalized drug dosages - determined by the application of genomic science - for optimal drug efficacy, reduced side effects, and overall improved patient outcomes.

[0004] The term 3D Pharming encompasses the various 3D printing and 2D material deposition technologies that are used to create personalized dosage forms. Since 1996, powder bed inkjet printing and fused deposition modeling (FDM) have become common 3D printing platforms, since these material deposition techniques allow for the fabrication of structures with 2D and 3D spatial gradients. [0005] Powder bed 3D printing, a technology originated at MIT, makes use of an inkjet printhead to deposit a layer of binder solution onto a powder bed containing the material desired for object construction. The object is defined through the use of computer-aided design (CAD) software and digitally sliced in detailed pieces of information that delineate each one of the layers to be printed through the process. After each layer deposition, a piston that supports the powder bed is lowered allowing a subsequent layer of powder to be spread and selectively bound. This process is repeated several times, stacking layers of solidified material until a predetermined 3D geometry is produced. Excess powder not bound is then removed exposing the final product, which can go through further processing to tune its final mechanical and physical properties.

[0006] Fused deposition modeling (FDM) developed as an alternative to the inherent limitations of powder bed 3D printing. This technique involves the melting, extrusion, and layer by layer deposition of materials that after solidification result in objects with predetermined structures. To control the pore size and the configuration of the object, variables such as raster angle and thickness, space between rasters, and the extrusion tip diameter can be manipulated. The appropriate heat transfer characteristics and rheological properties are the most critical material qualities evaluated for FDM use. Molten metals, self-hardening waxes, and thermoplastic materials such as nylon, acrylonitrile butadiene styrene, and polyvinyl chloride have been utilized successfully.

SUMMARY OF THE INVENTION

[0007] Many embodiments are directed to pharmaceutical bioinks, pharmaceutical formulations, and methods of printing pharmaceutical bioinks.

[0008] In an embodiment, a hydrophobic pharmaceutical ink includes a hydrophobic photocurable resin capable of being cured by visible light, a hydrophobic pharmaceutical active ingredient, a photoinitiator capable of initiating polymerization of the hydrophobic photocurable resin, and a co-initiator capable of inducing free radical polymerization of the hydrophobic photocurable resin.

[0009] In another embodiment, the hydrophobic pharmaceutical active ingredient is one of: Naproxen, Spironolactone, Ibuprofen, Eplerenone, Aspirin, and Simvastatin. [0010] In yet another embodiment, the hydrophobic pharmaceutical active ingredient is one of: a non-steroidal medication, an anti-inflammatory medication, an allergy medication, an analgesic, an antacid, an anticholinergic, an antidiarrheal, an antiemetic, an antiflatulent, an antihistamine, an antirheumatic, an antitussive, a bronchodilator, a decongestant, an expectorant, a laxative, a sleep aid, a sedative, a smoking deterrent, an antidepressant, a stimulants or a stomach acidifier.

[0011] In a further embodiment, the hydrophobic photocurable resin is poly(ethylene glycol)diacrylate (PEGDA).

[0012] In still yet another embodiment, the photoinitiator is one of: Eosin Y, Camphorquinone, Riboflavin, and Fluorescein.

[0013] In yet a further embodiment, the co-initiator is one of: m-PEG amine, polyethylene glycol) methyl ether amine, L-Arginine, and N-Phenylglycine.

[0014] In an even further embodiment, a hydrophobic pharmaceutical ink further utilizes a preform tablet capable of receiving the hydrophobic pharmaceutical ink.

[0015] In yet an even further embodiment, the preform tablet is composed of cellulose material and infused with polyethylene glycol).

[0016] In still yet an even further embodiment, the preform tablet is composed of a hydrophobic photocured polymer, wherein the photocured polymer is formed utilizing a hydrophobic photocurable resin capable of being cured by visible light, a photoinitiator capable of initiating polymerization of the hydrophobic photocurable resin, a co-initiator capable of inducing free radical polymerization of the hydrophobic photocurable resin, and visible light.

[0017] In still yet an even further embodiment, a hydrophobic pharmaceutical ink further utilizes at least one of: a coating agent, a disintegrating agent, an excipient, a surfactant, or a lubricant.

[0018] In an embodiment, a pharmaceutical formulation includes a hydrophobic photocured polymer. The photocured polymer is formed utilizing a hydrophobic photocurable resin capable of being cured by visible light, a hydrophobic pharmaceutical active ingredient, a photoinitiator capable of initiating polymerization of the hydrophobic photocurable resin, a co-initiator capable of inducing free radical polymerization of the hydrophobic photocurable resin, and visible light. [0019] In another embodiment, the hydrophobic pharmaceutical active ingredient is one of: Naproxen, Spironolactone, Ibuprofen, Eplerenone, Aspirin, and Simvastatin.

[0020] In yet another embodiment, the hydrophobic pharmaceutical active ingredient is one of: a non-steroidal medication, an anti-inflammatory medication, an allergy medication, an analgesic, an antacid, an anticholinergic, an antidiarrheal, an antiemetic, an antiflatulent, an antihistamine, an antirheumatic, an antitussive, a bronchodilator, a decongestant, an expectorant, a laxative, a sleep aid, a sedative, a smoking deterrent, an antidepressant, a stimulants or a stomach acidifier.

[0021] In a further embodiment, the hydrophobic photocurable resin is poly(ethylene glycol)diacrylate (PEGDA).

[0022] In still yet another embodiment, the photoinitiator is one of: Eosin Y, Camphorquinone, Riboflavin, and Fluorescein.

[0023] In yet a further embodiment, the co-initiator is one of: m-PEG amine, polyethylene glycol) methyl ether amine, L-Arginine, and N-Phenylglycine.

[0024] In an even further embodiment, the pharmaceutical formulation further includes a preform tablet. The hydrophobic photocured polymer is deposited within the preform tablet.

[0025] In yet an even further embodiment, the preform tablet is composed of cellulose material and infused with polyethylene glycol).

[0026] In still yet an even further embodiment, the preform tablet is composed of a hydrophobic photocured polymer. The photocured polymer is formed utilizing a hydrophobic photocurable resin capable of being cured by visible light, a photoinitiator capable of initiating polymerization of the hydrophobic photocurable resin, a co-initiator capable of inducing free radical polymerization of the hydrophobic photocurable resin, and visible light.

[0027] In still yet an even further embodiment, the pharmaceutical formulation further includes an outer layer composed of a hydrophobic photocured polymer. The photocured polymer is formed utilizing a hydrophobic photocurable resin capable of being cured by visible light, a photoinitiator capable of initiating polymerization of the hydrophobic photocurable resin, a co-initiator capable of inducing free radical polymerization of the hydrophobic photocurable resin, and visible light. [0028] In still yet an even further embodiment, the pharmaceutical formulation further includes at least one of: a coating agent, a disintegrating agent, an excipient, a surfactant, or a lubricant.

[0029] In still yet an even further embodiment, the pharmaceutical formulation further includes a hydrophilic photocured polymer. The photocured polymer is formed utilizing a hydrophilic photocurable resin capable of being cured by visible light, a hydrophilic pharmaceutical active ingredient, a photoinitiator capable of initiating polymerization of the hydrophobic photocurable resin, a co-initiator capable of inducing free radical polymerization of the hydrophilic photocurable resin, and visible light.

[0030] In an embodiment, a pharmaceutical bioink is deposited. The bioink includes a photocurable hydrophobic resin, a hydrophobic active ingredient, a photoinitiator, and a co-initiator. The photoinitiator is capable of initiating polymerization of the hydrophobic photocurable resin and the co-initiator is capable of inducing free radical polymerization of the hydrophobic photocurable resin. The bioink is cured by exposing the hydrophobic resin to visible light.

[0031] In another embodiment, the depositing and curing steps are performed simultaneously.

[0032] In yet another embodiment, the hydrophobic pharmaceutical active ingredient is one of: Naproxen, Spironolactone, Ibuprofen, Eplerenone, Aspirin, and Simvastatin.

[0033] In a further embodiment, the hydrophobic pharmaceutical active ingredient is one of: a non-steroidal medication, an anti-inflammatory medication, an allergy medication, an analgesic, an antacid, an anticholinergic, an antidiarrheal, an antiemetic, an antiflatulent, an antihistamine, an antirheumatic, an antitussive, a bronchodilator, a decongestant, an expectorant, a laxative, a sleep aid, a sedative, a smoking deterrent, an antidepressant, a stimulants or a stomach acidifier.

[0034] In still yet another embodiment, the hydrophobic photocurable resin is polyethylene glycol)diacrylate (PEGDA).

[0035] In yet a further embodiment, the photoinitiator is one of: Eosin Y,

Camphorquinone, Riboflavin, and Fluorescein.

[0036] In an even further embodiment, the co-initiator is one of: m-PEG amine, poly(ethylene glycol) methyl ether amine, L-Arginine, and N-Phenylglycine. [0037] In yet an even further embodiment, the pharmaceutical bioink is deposited within a preform tablet.

[0038] In still yet an even further embodiment, the preform tablet is composed of cellulose material and infused with poly(ethylene glycol).

[0039] In still yet an even further embodiment, the preform tablet is composed of a hydrophobic photocured polymer. The photocured polymer is formed utilizing a hydrophobic photocurable resin capable of being cured by visible light, a photoinitiator capable of initiating polymerization of the hydrophobic photocurable resin, a co-initiator capable of inducing free radical polymerization of the hydrophobic photocurable resin, and visible light.

[0040] In still yet an even further embodiment, the bioink further includes at least one of: a coating agent, a disintegrating agent, an excipient, a surfactant, or a lubricant.

[0041] In still yet an even further embodiment, the viscosity of the bioink is less than 20 mPa ^* s.

[0042] In still yet an even further embodiment, the temperature the bioink is increased above room temperature to ensure that the viscosity of the bioink is less than 20 mPa ^* s.

[0043] In still yet an even further embodiment, the length of time of the curing step is optimized for active ingredient release.

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The description and claims will be more fully understood with reference to the following figures and data graphs, which are presented as exemplary embodiments of the invention and should not be construed as a complete recitation of the scope of the invention.

[0045] Fig. 1 provides images of polymerized poly(ethylene glycol)diacrylate gels loaded with naproxen in accordance with various embodiments of the invention.

[0046] Fig. 2 provides images of polymerized poly(ethylene glycol)diacrylate gels loaded with ibuprofen in accordance with various embodiments of the invention.

[0047] Figs. 3A to 3C provide data of tensile strength, viscosity, and storage modulus of polyethylene glycol)diacrylate gels having various concentrations of PEGDA, each gel loaded with naproxen, generated in accordance with various embodiments. [0048] Fig. 4 data of viscosity of poly(ethylene glycol)diacrylate gels having various concentrations of PEGDA, each gel loaded with ibuprofen, generated in accordance with various embodiments.

[0049] Fig. 5 provides data of storage modulus of poly(ethylene glycol)diacrylate gels having various concentrations of PEGDA, each gel loaded with ibuprofen, generated in accordance with various embodiments.

[0050] Figs. 6A to 6C provide data of tensile of poly(ethylene glycol)diacrylate gels having various concentrations of either loaded naproxen or ibuprofen, generated in accordance with various embodiments.

[0051] Fig. 7 provides SEM images of polymerized bioinks, generated in accordance with various embodiments of the invention.

[0052] Fig. 8 provides a SEM images of polymerized bioinks, generated in accordance of various embodiments of the invention.

[0053] Fig. 9 provides images of droplet formation sequence of a poly(ethylene glycol)diacrylate bioink loaded with naproxen, generated in accordance of various embodiments of the invention.

[0054] Fig. 10 provides images of droplet formation sequence of a poly(ethylene glycol)diacrylate bioink loaded with ibuprofen, generated in accordance of various embodiments of the invention.

[0055] Figs. 11A to 11C provide exemplary schematics of bioink loadable preform tablets in accordance of various embodiments of the invention.

[0056] Figs. 12A to 12F provide light and SEM images of uncoated and coated preform tablets, generated in accordance of various embodiments of the invention.

[0057] Figs. 13A and 13B provide data of tensile strength of a preform tablet, generated in accordance of various embodiments of the invention.

[0058] Figs. 14A and 14B provide data of time-course drug dissolution from tablets loaded with naproxen, generated in accordance of various embodiments of the invention.

[0059] Figs. 15A and 15B provide images of patterning and spatial control bioink through an inkjet deposition process, generated in accordance of various embodiments of the invention. [0060] Fig. 16 provides data of gelation kinetics obtained through in-situ photorheology of a hydrophilic bioink, generated in accordance of various embodiments of the invention.

[0061] Fig. 17 provides images of polymerized hyaluronic acid gels loaded with Lisinopril and polymerized poly(ethylene glycol)diacrylate gels loaded with Spironolactone in accordance of various embodiments of the invention.

[0062] Fig. 18A provides data of tensile strength of polymerized hyaluronic acid gels loaded with various concentrations of Lisinopril, generated in accordance of various embodiments of the invention

[0063] Fig. 18B provides data of tensile strength of 30% polymerized polyethylene glycol)diacrylate gels loaded with various concentrations of Spironolactone, generated in accordance of various embodiments of the invention.

[0064] Fig. 19 provides data of tensile strength of 100% polymerized poly(ethylene glycol)diacrylate gels loaded with various concentrations of Spironolactone, generated in accordance of various embodiments of the invention.

[0065] Figs. 20A and 20B provide SEM images of a polymerized hyaluronic acid gel loaded with Lisinopril and a polymerized poly(ethylene glycol)diacrylate gel loaded with Spironolactone, generated in accordance of various embodiments of the invention.

[0066] Fig. 21 provides images of droplet formation sequence of hyaluronic acid bioink loaded with Lisinopril, generated in accordance of various embodiments of the invention.

[0067] Fig. 22 provides images of droplet formation sequence of poly(ethylene glycol)diacrylate gel loaded with Spironolactone, generated in accordance of various embodiments of the invention.

[0068] Figs. 23A to 23C provide of an example of a multi-compartment preform tablet in accordance of various embodiments of the invention.

[0069] Figs. 24A to 24D provide SEM images of untreated and coated preform tablets, generated in accordance of various embodiments of the invention.

[0070] Fig. 25 provides an image of polymerized hyaluronic acid gels loaded with Lisinopril and polymerized poly(ethylene glycol)diacrylate gels loaded with Spironolactone deposited within a preform table in accordance of various embodiments of the invention. [0071] Fig. 26 provides data time-course drug dissolution from tablets loaded with Lisinopril and Spironolactone, generated in accordance of various embodiments of the invention.

[0072] Fig. 27 provides an image of a polymerized hyaluronic acid gel loaded with Lisinopril and a polymerized polyethylene glycol)diacrylate gel loaded with Spironolactone after 24 hours of dissolution, generated in accordance of various embodiments of the invention.

DETAILED DESCRIPTION

[0073] Turning now to the drawings and data, a number of embodiments of pharmaceuticals that are formulated utilizing photocurable resin bioinks are provided. Various embodiments are directed to photocurable resin bioinks, which undergo a stabilization reaction in a controlled manner when exposed to visible light. In several embodiments, photocurable resin bioinks are mixed with at least one active ingredient to disperse within a tablet. Tablets, in accordance with numerous embodiments, can be preform tablets (e.g., pressed tablets or photocured tablets) to be filled with photocurable resin bioink; or, in accordance with alternative embodiments, tablets are formed using photocurable resin bioinks via methods as described herein.

[0074] A multitude of embodiments are directed to photocurable resin bioinks that are hydrophobic. The choice of resin often depends on an active ingredient’s hydrophobicity. More embodiments are directed to the use of hydrophobic photocurable resin bioinks in combination with hydrophilic resins. Accordingly, numerous embodiments are directed to tablets incorporating both hydrophilic and hydrophobic bioinks such that the tablets can further incorporate hydrophilic and hydrophobic active ingredients. In many embodiments, a hydrophobic resin bioink incorporates polyethylene glycol). In several embodiments, a hydrophilic resin bioink incorporates hyaluronic acid, glycol chitosan, sodium alginate, or a combination thereof.

[0075] In many embodiments, active ingredients are also incorporated into tablets. In some embodiments, active ingredients are distributed along with photocurable resin bioinks. Embodiments also integrate active ingredients within a resin, which may allow for evenly dispersed ingredients. Numerous active ingredients can be utilized in conjunction with photocurable active ingredients and the precise selection and amount of active ingredient depends on a treatment and dosage regime as understood by those skilled in the art.

[0076] Embodiments are also directed to the use of visible light to cure resin bioinks. Accordingly, a number of embodiments incorporate a photoreactive substituent that when exposed to visible light cures the bioink into a resin. In some embodiments acrylate, dimethacrylate, or divinyl ether substituents are added to polyethylene glycol) to make poly(ethylene glycol)diacrylate (PEGDA). In accordance with multiple embodiments, PEGDA can be used along with a photoinitiator (e.g., Eosin Y, Camphorquinone, Riboflavin, Fluorescein) and a co-initiator (e.g., m-PEG amine, poly(ethylene glycol) methyl ether amine, L-Arginine, N-Phenylglycine) to induce free radical polymerization, forming a gel-like resin.

[0077] In several embodiments, inkjets are used to controllably dispense and distribute photocurable resin bioinks. In some embodiments, inkjets dispense photocurable resin bioinks into a preform tablet. Various embodiments utilize inkjets to distribute photocurable resin bioinks to form tablet casings, and/or tablet themselves (i.e. , no preform tablet). Accordingly, in some embodiments inkjets controllably dispense photocurable resin bioinks such that an outer layer (typically without active ingredient) is cured, which allows inkjets to continue to dispense photocurable resin bioinks (typically with active ingredient) into the inner portions such that a whole pharmaceutical is formulated. Alternatively, in some embodiments, inkjets controllably dispense photocurable resin bioinks (typically without active ingredients) such that outer tablet casing is formed to render a preformed tablet, which can be stored and subsequently filled at a later time. And in some embodiments, a preform tablet composed of an alternative material (e.g., cellulose) is utilized to fill with photocurable resin bioinks. Any pharmaceutically acceptable material can be utilized as the outer layer of a preform tablet, as would be understood in those skilled in the art.

[0078] A number of embodiments utilize PolyJet technology, which can dispense photocurable materials under the presence of a constant light source such that resins simultaneously cured as they are deposited. Furthermore, inkjets can utilize hundreds to thousands, if not more, biocompatible print heads to increase the speed of printing. [0079] A number of embodiments are directed to methods of tablet formation. Accordingly, several embodiments utilize a hydrophobic photocurable resin bioink, photoinitiators, and active ingredients along with an inkjet to formulate a tablet via a three- dimensional pharming process, in which the bioink along with the other ingredients is layered into a tablet. In some embodiments, a tablet combines a hydrophobic photocurable resin bioink with a hydrophilic resin bioink such that at least one layer of each is formulated into a tablet. Furthermore, various embodiments are directed to methods to strategically layer various active ingredients within the tablet. In some such embodiments, some active ingredients are incorporated within the tablet to be released quickly while other active ingredients are incorporated for sustained release.

[0080] In many embodiments, generated tables are tailored to provide patients with personalized medicine. In some embodiments, the composition and dosage of a tablet is custom designed based on an individual’s attributes, such as their genetic, genomic, epigenomic, family history, and current prescriptions. A number of embodiments are directed to very controlled dosage of ingredients. The use of inkjets can precisely control picoliter amounts of bioink deposits, allowing for very precise dosage amount. In many embodiments, personalized tablets are generated in a hospital, pharmacy, healthcare provider’s office, or other customer-based location for convenient generation and/or compounding.

Formulations

[0081] Provided herein are various embodiments of pharmaceutical compositions which are formulated utilizing hydrophobic photocurable resin bioink and further incorporate one or more of certain compounds disclosed herein, or one or more pharmaceutically acceptable salts, prodrugs, or solvates thereof, together with one or more pharmaceutically acceptable carriers thereof and optionally one or more other active ingredients. Proper formulation is dependent upon the route of administration chosen. Any of the well-known techniques, carriers, and excipients may be used as suitable and as understood in the art. Pharmaceutical compositions may be formulated as a modified release dosage form, including delayed-, extended-, prolonged-, sustained-, pulsatile-, controlled-, accelerated- and fast-, targeted-, programmed-release, and gastric retention dosage forms. These dosage forms can be prepared utilizing the various method embodiments as described herein.

[0082] The term "active ingredient" refers to a compound, which is administered, alone or in combination with one or more pharmaceutically acceptable excipients or carriers, to a subject for treating, preventing, or ameliorating one or more symptoms of a disorder.

[0083] The compounds disclosed herein can exist as therapeutically acceptable salts. The term "therapeutically acceptable salt," as used herein, represents salts or zwitterionic forms of the compounds disclosed herein which are therapeutically acceptable as defined herein. The salts can be prepared during the final isolation and purification of the compounds or separately by reacting the appropriate compound with a suitable acid or base. Therapeutically acceptable salts include acid and basic addition salts. For a more complete discussion of the preparation and selection of salts, refer to "Handbook of Pharmaceutical Salts, Properties, and Use," Stah and Wermuth, Ed., (Wiley-VCH and VHCA, Zurich, 2002) and Berge et al, J. Pharm. Sci. 1977, 66, 1 -19.

[0084] Several embodiments incorporate at least one active ingredient along with hydrophobic photocurable resin bioink. In some embodiments, an active ingredient is incorporated into a deposited bioink layer, especially layers that are hydrophobic. In many embodiments, a hydrophobic active ingredient is incorporated into a layer exclusively containing hydrophobic constituents. In some such embodiments, a hydrophobic active ingredient is excluded from a layer having hydrophilic ingredients.

[0085] A number of active ingredient can be used in the methods and formulations of the present invention, especially those exhibiting hydrophobic properties that would cooperate well in a hydrophobic resin bioink. In some embodiments, an active ingredient is selected from the group consisting of Naproxen, Spironolactone, Ibuprofen, Eplerenone, Aspirin, Simvastatin, and combinations thereof, wherein any of said active ingredients can be present as a pharmaceutically acceptable salt. In several embodiments, an active ingredient is selected from the group consisting of non-steroidal medications, anti-inflammatory medications, allergy medications, analgesics, antacids, anticholinergics, antidiarrheals, antiemetics, antiflatulents, antihistamines, antirheumatics, antitussives, bronchodilators, decongestants, expectorants, laxatives, sleep aids, sedatives, smoking deterrents, antidepressants, stimulants and stomach acidifiers, and combinations thereof, wherein any of the active ingredients can be present as its pharmaceutically acceptable salt.

[0086] Numerous coating agents can be used in accordance with various embodiments of the invention. In some embodiments, the coating agent is one which acts as a coating agent in conventional delayed release oral formulations, including polymers for enteric coating. Examples include hypromellose phthalate (hydroxy propyl methyl cellulose phthalate; HPMCP); hydroxypropylcellulose (HPC; such as KLUCEL®); ethylcellulose (such as ETHOCEL®); and methacrylic acid and methyl methacrylate (MAA/MMA; such as EUDRAGIT®).

[0087] Various embodiments of formulations also include at least one disintegrating agent. In some embodiments, a disintegrating agent is a super disintegrant agent. In many embodiments, disintegrants are combined with a resin. Additional disintegrating agents include, but are not limited to, agar, calcium carbonate, maize starch, potato starch, tapioca starch, alginic acid, alginates, certain silicates, and sodium carbonate. Suitable super disintegrating agents include, but are not limited to crospovidone, croscarmellose sodium, AMBERLITE (Rohm and Haas, Philadelphia, Pa.), and sodium starch glycolate.

[0088] Several embodiments of a formulation further utilize other components and excipients. For example, sweeteners, flavors, buffering agents, and flavor enhancers to make the dosage form more palatable. Sweeteners include, but are not limited to, fructose, sucrose, glucose, maltose, mannose, galactose, lactose, sucralose, saccharin, aspartame, acesulfame K, and neotame. Common flavoring agents and flavor enhancers that may be included in the formulation of the present invention include, but are not limited to, maltol, vanillin, ethyl vanillin, menthol, citric acid, fumaric acid, ethyl maltol and tartaric acid.

[0089] Multiple embodiments of a formulation also include a surfactant. In certain embodiments, surfactants are selected from the group consisting of Tween 80, sodium lauryl sulfate, and docusate sodium.

[0090] Various embodiments of a formulation also include a lubricant. In certain embodiments, lubricants are selected from the group consisting of magnesium stearate, stearic acid, sodium stearyl fumarate, calcium stearate, hydrogenated vegetable oil, mineral oil, polyethylene glycol, polyethylene glycol 4000-6000, talc, and glyceryl behenate.

[0091] Modes of administration, in accordance with multiple embodiments, include, but are not limited to, oral or transmucosal (e.g., sublingual, nasal, vaginal or rectal). The actual amount of drug needed will depend on factors such as the size, age and severity of disease in the afflicted individual. The actual amount of drug needed will also depend on the effective concentration ranges of the various active ingredients.

[0092] In some embodiments, tablets formulated with hydrophobic photocurable resin bioink are administered in a therapeutically effective amount as part of a course of treatment. As used in this context, to "treat" means to ameliorate at least one symptom of a disorder to be treated or to provide a beneficial physiological effect. For example, one such amelioration of a symptom could be reduction of inflammation-like symptoms.

[0093] A therapeutically effective amount can be an amount sufficient to prevent reduce, ameliorate or eliminate the symptoms of diseases or pathological conditions susceptible to such treatment, such as, for example, common cold, influenza, or headache.

[0094] Dosage, toxicity and therapeutic efficacy of the compounds can be determined, e.g., by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., for determining the LDso (the dose lethal to 50% of the population) and the EDso (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD50/ED50. Compounds that exhibit high therapeutic indices are preferred. While compounds that exhibit toxic side effects may be used, care should be taken to design a delivery system that targets such compounds to the site of affected tissue in order to minimize potential damage to other tissue and organs and, thereby, reduce side effects.

[0095] Data obtained from cell culture assays or animal studies can be used in formulating a range of dosage for use in humans. If the pharmaceutical is provided systemically, the dosage of such compounds lies preferably within a range of circulating concentrations that include the ED50 with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed and the route of administration utilized. For any compound used in the method of the invention, the therapeutically effective dose can be estimated initially from cell culture assays. A dose may be formulated in animal models to achieve a circulating plasma concentration or within the local environment to be treated in a range that includes the IC50 (i.e. , the concentration of the test compound that achieves a half-maximal inhibition of neoplastic growth) as determined in cell culture. Such information can be used to more accurately determine useful doses in humans. Levels in plasma may be measured, for example, by liquid chromatography coupled to mass spectrometry.

[0096] An "effective amount" is an amount sufficient to effect beneficial or desired results. For example, a therapeutic amount is one that achieves the desired therapeutic effect. This amount can be the same or different from a prophylactically effective amount, which is an amount necessary to prevent onset of disease or disease symptoms. An effective amount can be administered in one or more administrations, applications or dosages. A therapeutically effective amount of a composition depends on the composition selected. The compositions can be administered one from one or more times per day to one or more times per week; including once every other day. The skilled artisan will appreciate that certain factors may influence the dosage and timing required to effectively treat a subject, including but not limited to the severity of the disease or disorder, previous treatments, the general health and/or age of the subject, and other diseases present. Moreover, treatment of a subject with a therapeutically effective amount of the compositions described herein can include a single treatment or a series of treatments. For example, several divided doses may be administered daily, one dose, or cyclic administration of the compounds to achieve the desired therapeutic result.

[0097] Preservatives and other additives, like antimicrobial, antioxidant, chelating agents, and inert gases, can also be present. (See generally, Remington: The Science and Practice of Pharmacy, 21 st Edition; Lippincott Williams & Wilkins: Philadelphia, PA, 2005.)

EXEMPLARY EMBODIMENTS

[0098] The embodiments of the invention will be better understood with the several examples provided within. Exemplary hydrophobic photocurable resin bioinks are provided that are capable of being used to formulate tablets with ideal properties. Also provided are various exemplary methods that may be utilized to manufacture and practice the various embodiments. Exemplary experiments characterizing generated tablets and the resultant data are also described, further clarifying and enabling one to practice the numerous embodiments.

Inkjet 3D Pharming of Hydrophobic Drugs

[0099] In the example provided herein, a pharmaceutical formulated by 3D pharming incorporates the following characteristics: 1 ) maintain the stability of the active ingredient, 2) able to be printed quickly, 3) able to be formulated in drug dispensing locations and healthcare provider’s offices, 4) able to incorporate hydrophilic and hydrophobic compounds, 5) able to be printed in various dosages of ingredients with great resolution, 6) able to amenable to operation in a GMP setting, 7) be cost-effective, 8) able to control of drug release profiles, 9) able to combine multiple compounds in a single tablet, and 10) able to be generated with controls for quality assurance. Inkjet printing allows for drug load resolution in the picomolar range, high spatial resolution that allows for drug gradients and printing of multiple drugs within a pill, while improving 3D pharming quality controls by monitoring the process of droplet formation and deposition through video cameras. Moreover, it allows for faster printing times when compared to other technologies and the equipment has lower costs compared to powder bed 3d printing and fused position modeling. Despite the potential of 3D Pharming, the technique is limited by the small amount of biocompatible photocurable materials currently available that satisfy the physical properties needed for inkjet printing. Recent work demonstrated the synthesis and use of a hyaluronic acid based photocurable bioink for the inkjet 3D Pharming of hydrophilic drugs (See G. F. Acosta-Valez, et al. Bioengineering 4, 1-1 1 (2017), the disclosure of which is herein incorporated by reference). Here, in this example, a poly(ethylene glycol) photocurable bioink is utilized for inkjet 3D Pharming of hydrophobic drugs, which constitute over 40% of the new chemical entities developed within the pharmaceutical industry. The low water solubility of these compounds is one of the major hurdles encountered when creating dosage forms, forcing active pharmaceutical ingredients (APIs) to be manufactured through powder compressed tablets or gel capsules, techniques which make it difficult to personalize for a patient. [0100] Low molecular weight polyethylene glycol)diacrylate (PEGDA (250 Da)) was utilized as a crosslinking agent of an exemplary photocurable formulation along with PEG (200 Da). Other components utilized were Eosin Y, a biocompatible photoinitiator with maximum absorbance in the visible light range, and m-PEG amine (350 Da) as co-initiator to induce free radical polymerization. Typical photocurable formulations make use of photoinitiators with a maximum absorbance within the UV light range. However, UV light can affect the stability of certain drugs, and could present a safety hazard for the operators of 3D pharming machinery. In contrast, visible light is a safe energy source to be used by operators through the curing process. Preform tablets, which were utilized to encapsulate the formulation, were manufactured through conventional powder compression technique. The perform tablets were made of microcrystalline cellulose, infused with PEG (35 kDa), and their inner surfaced was brushed with Eudragit E-100, a binder soluble under acidic conditions resulting in fast dissolution of the preform tablet. Naproxen was dispensed into the preform tablets as model compound for the dissolution studies due to its high hydrophobicity. Fast printing times were achieved and the concentration loaded of API was significantly enhanced when compared to aqueous formulations.

Photocurable Formula Preparation

[0101] The reagents PEGDA (250 Da), PEG (200 Da), Eosin Y, Naproxen, and Ibuprofen were obtained from Sigma-Aldrich (St. Louis, MO, USA) and used without further purification. PEGDA constituted the crosslinking agent and main compound of the bioink designed, along PEG 200 which was utilized as a solvent. Formulations with diverse PEGDA weight percentages ( I/I/PEGDA) and light exposure times ( TL) were made to manipulate the tensile strength of the gels. Eosin Y at a concentration of 1 mM was added to these formulations as a photo-initiator and 0.05 M mPEG-amine (350 Da, Creative PEG Works, Chapel Hill, NC, USA) was incorporated as a co-initiator. Naproxen was added at a concentration of 40 mg/mL and the solution was vortexed thoroughly until Eosin Y and Naproxen were completely dissolved. Gelation and Mechanical Properties

[0102] In order to assess the effect of different I/I/PEGDA values on the gel mechanical properties, formulations with 100%, 80%, 60%, 40%, and 20% PEGDA were prepared. One ml_ syringes (BD & Co., Franklin Lakes, NJ, USA), modified by removing their tips, were subsequently loaded with 50 pL of formulation and exposed to visible light (Volpi, V-lux 1000, Auburn, NY, USA) at an intensity of 120 mW/cm2 to induce gelation. The effect of different TL values on the tensile strength of tablets was measured by exposing the bioinks for durations of 20 s, 45 s, 1.5 min and 3 min. Moreover, the effect of drug concentration and drug choice in solution was assessed by polymerizing solutions with a I/I/PEGDA of 100%, a TL of 45 s and diverse concentrations of Naproxen and Ibuprofen. The tensile strength of gels with these two APIs was analyzed.

[0103] An Instron (5564 model) was used to measure the failure load of the resulting gels. Equation 1 was utilized to calculate their tensile strength (s), where D is the tablet diameter, H is the thickness, and F represents the failure load.

[0104] The surface tension (g) of the photocurable formulation was measured by Equation 2 using a tensiometer (Kimble Chase 14818 Tensiometer, Cole-Parmer, Vernon Hills, IL, United States), where h is the distance between menisci of the tube and the capillary, r is the radius of the capillary, p is the density of the formulation, and g is the acceleration due to gravity. The density was measured by weighing 1 ml_ of each formulation in a pre-weighed microcentrifuge tube and dividing the value by the predetermined volume.

1

Y = 2 ^hr pg ^E Q ²

[0105] The inverse of Ohnesorge Number, Z value, was calculated to assess the printability of the different formulas engineered. Equation 3 defines the Z value, where a is the radius of the piezoelectric nozzle printing orifice used to dispense the formulations and p, y, and h represent the density, surface tension, and viscosity of the photocurable formula, respectively. The viscosity of the formulations was measured with a rheometer (Discovery HR-2, TA Instruments, New Castle, DE, USA) using a 40 mm 2.016° cone and plate geometry with shear rate ranging from 10 to 100 Hz.

[0106] The swelling ratio (QM) of the PEGDA gels was measured by taking the ratio between the swelling mass (M _s ) and the dry mass ( MD ) of the gel, represented below in Equation 4. Gels were immersed in PBS for 3 days and weighed to obtain their swelling mass. Subsequently, the gels were lyophilized and their dry weight was measured.

„= _W M _s

E _q A

[0107] ln-situ photorheology was performed on a rheometer at constant strain of 1 % and angular frequency of 10 rad/sec. The visible light source was turned on after 30 s of data collection and the storage modulus (G’) of the sample was collected for a period of 10 min. In addition, a flow temperature ramp (25 °C - 50 °C) was performed to measure the viscosity of the photocurable formulas and their susceptibility to temperature, at a constant shear rate of 1 Hz.

Imaging Tablets with Scanning Electron Microscopy (SEM)

[0108] Cross-sectional images of the cylindrical tablets were captured with a NOVA 230 NanoSEM scanning electron microscope to further characterize the microstructure of the tablet. The voltage and spot size were set at 3.0 kV and 4.0, respectively, while the pressure mode was set at a low vacuum variable pressure of 50 Pa. Images on cross- sectional areas of 100% and 20% PEGDA gels were capture.

Preform Tablet Fabrication and Characterization

[0109] Drug-containing bioinks were directly printed into tablet preforms. The binder microcrystalline cellulose (Avicel® PH-103; FMC Corporation; Philadelphia, PA, USA), and the superdisintegrant croscarmellose sodium (5% (w/w); VIVASOL®; JRS Pharma, Patterson, NY, USA) were pressed into two fitting parts - a 100 pL well and a cap with a locational interference fit - via direct compression technique. A customized press design was used to make the preform tablets, which included two standard B-Type upper punches with tip modifications to produce the positive features of either the cap or the well, and one lower punch designed to sit flush on a hydraulic press stage with a tip that had 0.04-inch radius of curvature and a 0.02-inch blended landing. A standard 0.945 die with a 3/16-inch-deep TSM standard taper and an increased die bore dimension of 0.003 inch at the face of the die was used during tablet fabrication. The preform tablets (150 mg caps; 300 mg wells) were compressed with 10 kN of force, with a dwell time of 30 s. To prevent absorption of the drug- containing bioink into the preform tablet during printing, the well was infused with PEG (35 kDa) by submerging the tablet in an acetone solution containing 15% (w/w) PEG for 30 min at 55°C. Additionally, the well was brush-coated with Eudragit ® E100 (Evonik, Essen, Germany) (polymethacrylate copolymer) dissolved in acetone at 20% (w/w). The tablet hardness at different locations on the perform tablet was measured using Buehler Vickers Hardness indenter 1600-6305 (Buehler, Lake Bluff, IL, USA) with Vickers indentations up to 500 g load. Surface morphology of the preform tablet was characterized by scanning electron microscopy (NOVA NanoSEM 230, FEI Co., Hillsboro, OR, USA).

Drug Dispensing and Release Kinetics

[0110] A MicroFab piezoelectric dispenser (MJ-ABP-01 -080, MicroFab, Plano, TX, USA) with an 80pm diameter nozzle was utilized to test the droplet formation capacity of these formulations and for their subsequent dispense into preform tablets. A microdispensing system (MD-E-3000, Microdrop, Norderstedt, Germany) set at 46 V, with a pulse width of 16 ps and a frequency of 2000 Hz (droplets per second), was used to drive the piezoelectric dispenser. An analog camera (JAI CV-S3300) with a lens (Edmund Optics, Barrington, NJ, USA) and an LED were used to image droplet formation. Formulation with a I 1/PEGDA value of 100% was dispensed into preform tablets through the piezoelectric nozzle for a period of 5 min and exposed to light for 45 s or 20 s at 120 mW/cm ² , to analyze the effect of TL values on drug release. Additionally, formulation containing 20% PEGDA was pipetted into preform tablets (50 pL) and its drug release kinetics was analyzed to study softer gel precursor solutions that did not meet inkjet printing requirements at room temperature due to higher viscosities. After dispensing and light induced polymerization, a preform cap was attached to finalize the pharmaceutical product. The drug dissolution profile of the formulations was obtained by placing the tablets into Uni-cassettes (Tissue-Tek) and immersing them in a beaker containing 500 ml_ of dissolution medium, conditioned at 37 °C and stirred at 60 rpm. The dissolution medium was composed of monobasic potassium phosphate at a concentration of 1 .053 mM and a pH of 7.2. Aliquots (1 ml_) were taken from the dissolution bath of after 2, 6, 10, 12, 18, and 24 h of the dissolution, and the volume taken was replenished with fresh dissolution medium conditioned at 37 °C. Their drug concentration was determined by HPLC (Waters 2690 with a PDA 996 detector) at a wavelength of 330 nm.

2D Spatial Control

[0111] To demonstrate spatial control of the formulations upon dispensing and their potential applicability towards PolyJet printing, the dispensing system was attached to a robot (I&J7900- LF, l&J Fisnar Inc., Wayne, NJ, USA). The robot was programmed to dispense formulation in predetermined shapes (square and circle).

Statistical Analysis

[0112] Statistical analysis was performed with GraphPad Prism software (GraphPad Software, Inc., San Diego, CA). Statistical significance was assessed using single factor ANOVA test with a Tukey post-test and 95% confidence interval.

Formulation Characterization

[0113] Naproxen, a non-steroidal anti-inflammatory agent and the model drug used in this example, was dissolved in exemplary photocurable formulations at a concentration of 40 mg/ml_. This represents a significant solubility increase when compared to aqueous solutions, where the solubility for Naproxen is only 0.0159 mg/ml_. To quantify the effect on the mechanical properties of the PEGDA/PEG200 ratio in the formulation, gels with I 1/pEGDA of 20%, 40%, 60%, 80%, and 100% and a TL of 45 s were manufactured. Gels with lower I 1/PEGDA exhibited a higher opacity when compared to gels with higher 1 1/PEGDA, which had a higher transparency resembling the physical appearance of acrylic materials (Fig. 1) This characteristic was also observed in gels loaded with Ibuprofen (Fig. 2). [0114] The effect of light exposure time was quantified by submitting the formulations to 20 s, 45 s, 1.5 min, and 3 min of visible light an intensity of 120 mW/cm ² The diameter and thickness of the gels were 4.35 mm and 3.00 mm, respectively, for a 50 pL solution gel. The failure load of the gelled formulations was obtained in order to calculate their tensile strength using Equation 1. Figure 3A shows the tensile strength values for these formulations under different TL conditions. The tensile strength of the tablets increased with increasing PEGDA percent and extended light exposure times. Typical tensile strengths of commercially available tablets fall between 1 and 10 MPa [34] Gels with I 1/pEGDA of 40% or higher showcase desirable tensile strength values at determined TL values ranging from 20 s to 3 min.

[0115] Typically, solutions with viscosities values between 3-20 mPa*s are compatible with piezoelectric nozzles at room temperature. It is noted that certain piezoelectric nozzles exerting stronger piezo forces can dispense fluids with viscosities of up to 50 mPa*s. A flow temperature ramp was done to analyze the viscosity of the formulations at different temperatures (Fig. 3B). Solutions with I/I/PEGDA of 100%, 80%, and 60% fell within the viscosity values ideal for inkjet printing at room temperature, whereas solutions with I/I/PEGDA of 40% and 20% had values higher than 20 mPa*s, requiring minor temperature increases to fall within the printable category. Piezoelectric nozzles with heating capabilities could be utilized to print formulations with lower I/1/PEGDA, since their viscosity decreased significantly by increasing the temperature to 45 °C. Higher viscosity values were obtained when loading the bioinks with Ibuprofen at 180 mg/mL, showing the effect on viscosity of higher drug concentrations (Fig. 4).

[0116] ln-situ photo-rheology was performed to assess the gelation kinetics of the precursor solutions, where the storage modulus was recorded over time as the gelation proceeded (Fig. 3C). The results show that formulations achieve a higher storage modulus within the first 30 s of light exposure as the I/I/PEGDA increases, having a higher impact on formulations containing 40% PEGDA and above. Similar gelation times were obtained with bioinks carrying Ibuprofen at 1 80 mg/mL, demonstrating that quick polymerization can be achieved at higher API concentrations (Fig. 5). [0117] To assess the effect of drug concentration, gels with different Naproxen concentrations were made and their tensile strength was analyzed (Fig. 6A). The gels had a I/I/PEGDA of 100% and a TL of 45 s. Results show that the mechanical strength of the gels remains constant as the concentration increases up to a maximum of 40 mg/mL, after an initial decay in tensile strength when compared to a gel without drug. However, a decrease in tensile strength was observed as the drug concentration increased when using Ibuprofen, a common analgesic and antipyretic agent (Fig. 6B). This behavior is possibly caused by potential disruption of the gel microarchitecture due to higher amounts of API in solution and Ibuprofen’s higher hydrodynamic radius, when compared to Naproxen. Figure 6C compares the tensile strength of gels containing the same concentration of Naproxen and Ibuprofen. A statistical difference was observed between the gels containing Naproxen and the no drug gel condition, whereas no difference was observed between the Ibuprofen and no drug conditions. This indicated that the mechanical properties of the gels are affected by both, drug choice and its concentration.

[0118] To analyze the microstructure of the polymerized gels, SEM analysis was done on the cross-section of cured formulations with I/I/PEGDA of 100% and 20%, with Naproxen. Figure 7 reveals complete dissolution of the model drug at a concentration of 40 mg/mL, evidenced by the lack of Naproxen crystals within the gel. Furthermore, the SEM images show an increased porosity with decreased I/1/PEGDA, explaining the opacity observed on gels containing higher PEG200 percentages. Similar microarchitectures were observed in gels loaded with Ibuprofen at 180 mg/mL (Fig. 8).

[0119] The mesh size of the polymer matrix formed by each formulation was analyzed to know what size of molecules could be delivered successfully and its potential effect on drug release kinetics. Table 1 shows the mesh size obtained for each PEGDA formulation. Higher I/I/PEGDA resulted in smaller mesh size values due to an increased number of crosslinked PEGDA polymer chains. On the other hand, lower I/I/PEGDA resulted in larger mesh size values, shortening the time for drugs diffusing out through the matrix and yielding a faster drug release. Although drugs could be released through the matrix of the gel, the small mesh size limited the ability for immediate release. Therefore, only sustained release was observed for the formulations developed in this study. Naproxen has a hydrodynamic radius of 0.377 nm, allowing it to diffuse through the microarchitecture of the polymerized gel. Slightly smaller mesh sizes were obtained when exposing bioinks with a I 1/PEGDA of 20% and 40% to 3 min of light exposure time, denoting the effect of prolonged polymerization times in the architecture of the gels with low

PEGDA percentages (Table S1 ).

Table 1. Mesh size of polymerized gels with different ½7 _PEG DA values and a 7 of 45 s.

QM VS M, (Da) (if) ^/2 (A) x (A) 4.17 0.18 122.94 7.09 12.62 2.21 0.29 1 16.14 6.89 10.42 1 .40 0.39 103.05 6.49 8.88 1 .16 0.44 94.80 6.23 8.21 1 .04 0.46 89.15 6.04 7.80

Table S1. Mesh size of polymerized gels with different !4 _GDA values and a 71 of 3 min.

QM ^V S M, (Da) (H ) ^i/2 (A) x (A)

20% 2.9593 0.2334 120.4120 7.0185 1 1.3996

40% 2.0353 0.3068 1 14.4700 6.8431 10.1459

60% 1.4976 0.3756 105.5596 6.5714 9.1077

80% 1.2253 0.4237 97.2961 6.3090 8.3998

100% 1 0443 0.4631 89.4085 6.0478 7.8168

Droplet Formation

[0120] The inverse of the Ohnesorge number, or Z value, was calculated to define the printability of the formulations engineered (Equation 3). This dimensionless number takes in consideration the inertia and surface tension forces of a fluid over its viscosity forces, in order to define its droplet formation capabilities. This parameter also considers the orifice radius of the nozzle being used for inkjet printing. Values ranging from 4 to 14 have been defined as printable substances in the literature, where values above 14 exhibit the formation of satellite droplets and values below 4 present strong viscous forces. The surface tension, viscosity, and density of the formulations was quantified to determine the Z value. In regards to Figure 3B the viscosity of formulations with different I 1/pEGDA and their temperature susceptibility was presented. Fluids with surface tensions falling within the range of 30-70 mN/m are generally considered printable fluids. Table 2 shows the values obtained for these parameters and the corresponding Z values for each formula at room temperature. Table 2. Droplet formation capacity of Naproxen loaded bioinks.

[0121] Formulation with a I/I/PEGDA of 100% fell within the printable range, since it achieved a viscosity value below 20 mPa ^* s. However, it is suggested that formulations with lower I 1/PEGDA could fall into this category by using piezoelectric nozzles with heating capabilities. The surface tension and densities obtained were adequate for inkjet printing. From this analysis, it can be concluded that viscosity was the determining factor in the printability of various formulations, since the other variables had similar values. Figure 9 shows the droplet formation process for a formula with a 1 1/PEGDA of 100% and Naproxen at a concentration of 40 mg/ml_. This test was performed with a driver set at 46 V, with a pulse width of 16 ps, and a frequency of 2000 Hz. Similar images were obtained using bioink loaded with 180 mg/mL of Ibuprofen (Fig. 10). The formulations sustained a stable printing time of 1 h and a permissible idle time between prints was of 3 min.

Preform Tablet Characterization

[0122] As Microcrystalline cellulose was chosen as the diluent for the preform tablet because of its good compressibility and compactibility resulting from the powder’s ability to undergo plastic deformation and form hydrogen bonds between neighboring hydroxyl groups. These properties are particularly important for the successful formation of the preform tablet’s positive features. Additionally, it is broadly compatible with APIs and physiologically inert. To facilitate rapid disintegration of the preform tablet, croscarmellose sodium was added to the preform tablet at 5% (w/w). It was previously shown that at least 5 kN compression force was required to produce tablets with adequate mechanical strength and handling properties, and that the addition of the superdisintegrant to the preform tablet did not greatly impact the mechanical properties of the tablet. As such, 10 kN of force were used to fabricate the perform tablets in this study (Fig. 11 ). SEM analysis (Fig. 12, left) and the surface hardness profiles of uncoated preform tablets (Fig. 13) show low-density regions exist in the periphery and a high-density area exists in the center of the tablet face. It has been previously reported that die wall lubrication can have an impact on the density distribution. Specifically, non-lubricated tablets had a high- density area in the periphery and the material in the center was less dense, while the lubricated die tablet showed an opposite pattern. This is likely due to the low friction coefficient between the walls of the punch and the powder, allowing for powder movement relative to the punch during compression. The custom-made punches used in this study were coated with magnesium stearate as a lubricant to facilitate the removal of the positive features of the perform tablet from the punch.

[0123] The preform tablet’s density variation negatively impacted the performance of tablets during printing of the bioink. The increased porosity in the low-density regions of the preform tablet allowed the hydrophobic bioinks to soak into the preform tablet during printing, which not only weakened the preform tablet, but also negates the advantages of using 3D printing for pharmaceutical applications, such as control over drug positioning. To fill the pores in the low- density regions, the preform tablets were first soaked in a high- molecular weight PEG (35 kDa) solution. High-molecular weight PEG was selected because it is immiscible with the low-molecular weight PEGDA in the bioink. Additionally, a thin coating of Eudragit® E100 was added to the preform tablet well to further inhibit the absorption of the bioink during printing. SEM analysis shows that the polymeric coating fill the pores of the preform tablet’s low-density regions (Fig. 12, right).

Tablet Dissolution Test

[0124] Formulations with a I/I/PEGDA of 100%, a TL of 45 s or 20 s, and Naproxen at a concentration of 40 mg/mL, were dispensed into blank preform tablets and subsequently exposed to light to induce gelation. After polymerization, the tablets were capped and immersed into 500 ml_ of dissolution medium, conditioned at 37 °C and stirred at 60 rpm. Aliquots were taken after 2, 6, 10, 12, 18, and 24 h of dissolution and their drug concentration was analyzed through HPLC. The results show that the release profile of drugs can be manipulated by controlling the light exposure time applied to the formulations, where lower TL values result on faster release kinetics (Fig. 14A). To assess the release profile of formulations with lower l l/PEGDA, formulation with 20% 1/1/PEGDA was pipetted into preform tablets to study its release kinetics. The release profile obtained indicates that faster release kinetics can be obtained by printing low 1/1/PEGDA formulations using piezoelectric nozzles with heating capabilities. Figure 14B shows a statistically significant difference in drug release after 24 h of dissolution when changing TL from 45 s to 20 s for the same I/I/PEGDA value (100%).

2D Spatial Control

[0125] PolyJet is a 3D printing technique where photocurable formulations are dispensed on a tray under constant light exposure, resulting in solid objects with diverse geometries and mechanical properties. To show that the 2D deposition of these formulations could be controlled in order to apply them in PolyJet technology, the piezoelectric nozzle was attached to a robot programed to form circle and square geometries. Figure 15 shows formulation with a I/I/PEGDA of 100% dispensed upon a flat surface and the formation of predetermined geometries. The ability to polymerize these formulations upon light exposure, its droplet formation capability, and the capacity to load hydrophobic drugs, makes the materials designed translatable into PolyJet printing for the 3D pharming of hydrophobic APIs, eliminating the need of a preform tablet as a vessel.

Inkjet 3D Pharming of Hydrophobic/Hydrophilic Combination Drugs

[0126] In this example, a hyaluronic acid based photocurable bioink for the inkjet 3D Pharming of hydrophilic compounds is combined with a poly(ethylene glycol) diacrylate based bioink capable of loading hydrophobic drugs to yield a combination therapy for the treatment of hypertension. The active pharmaceutical ingredients (APIs) Lisinopril and Spironolactone were chosen as model drugs. Lisinopril is an angiotensin-converting enzyme inhibitor (ACE I) for the treatment of hypertension having a high degree hydrophilicity. Spironolactone is a potassium-sparing diuretic for the treatment of hypertension and congestive heart failure, but is a hydrophobic drug. Formulated bioinks were dispensed through a piezoelectric nozzle at room temperature into a blank preform tablet featuring two compartments, one for each formulation. The preform tablet parts were manufactured through powder bed 3D printing, using calcium sulfate as excipient. Once the drugs were dispensed, they were exposed to light to induce photopolymerization of the bioinks, and the preform tablet parts were assembled to finalize the pharmaceutical product. A sustained drug release profile was achieved for both APIs in this oral dosage form. This 3D pharming method allows for the fabrication of oral compound therapies at room temperature, with quick manufacturing times, and controlled dosages.

Hydrophilic Photocurable Bioink Preparation

[0127] A Hyaluronic Acid Norbornene (HANB) was synthesized. Hyaluronic acid (60 kDa-MW) (Genzyme Corporation, Cambridge, MA, USA) was modified with hydrazide groups through a reaction with adipic acid dihydrazide (ADH) in the presence of 1 -ethyl- 3-(dimethylaminopropyl) carbodiimide hydrochloride (EDC). The product was dialyzed for 3 days against Dl water (Fisherbrand regenerated cellulose, MWCO 12,000-14,000 Da, Houston, TX, USA), frozen, and lyophilized. On a second reaction, the HA functionalized with hydrazide groups (HA-ADH) was reacted cis-5-norbornene-enc/o-2,3-dicarboxylic anhydride (Sigma- Aldrich, St. Louis, MO, USA), resulting in norbornene functionalized HA (HANB). The product was dialyzed with Dl water for 3 days, filtered, lyophilized, and stored at -20 °C. HANB was characterized by proton nuclear magnetic resonance spectroscopy (1 H NMR) on a Bruker AV300 broad band FT NMR Spectrometer (Billerica, MA, USA). The degree of modification obtained was ~ 50%.

[0128] Following its synthesis, HANB was dissolved in phosphate buffered solution (PBS) and mixed with polyethylene glycol) dithiol (1500 Da, PEGDT) at a crosslinking ratio (ratio of thiol groups to norbornene groups, /ratio) of 0.6. HANB was added at a weight percent ( I 1/HANB) of 3%. Eosin Y was added as a photoinitiator and poly(ethylene glycol) (PEG200) was added to optimize the viscosity of the formulation. Each of these two components constituted 10% v/v of the bioink. Lisinopril dihydrate (Fisher Scientific, Pittsburgh, PA, USA) was added at a concentration of 40 mg/mL. All chemicals were purchased from Sigma-Aldrich (St. Louis, MO, USA) unless otherwise stated. Hydrophobic Photocurable Bioink Preparation

[0129] The hydrophobic bioink was formulated as described in the previous example, with minor modifications. Briefly, bioink was composed of 30% poly(ethylene glycol) diacrylate (PEGDA, 250 Da), 50% PEG200, and 20% ethanol. Eosin Y (1 .0 mM) and mPEG-amine (0.05 M) (350 Da, Creative PEG Works, Chapel Hill, NC, USA) were added as photoinitiator and co-initiator, respectively. Spironolactone was added at a concentration of 20 mg/mL.

Bioinks Gelation and Mechanical Properties

[0130] The tensile strength of polymerized gels was analyzed to characterize the mechanical properties of the bioinks. 1 mL syringes (BD & Co., Franklin Lakes, NJ, USA), modified by eliminating their tips, were loaded with 50 pL of bioink. Gels were formed with hydrophilic and hydrophobic bioinks by exposing them to visible light at an intensity of 120 mW/cm2 for a period of 2 min and 1 min, respectively. Additionally, the tensile strength of gels with varied drug concentrations was measured to analyze the impact of drug load on the mechanical properties of the polymerized bioinks. An Instron (5564 model) was used to measure the failure load of the gels fabricated. Tensile strength (s) was calculated through Equation 5, where D is the tablet diameter, H is the thickness, and F represents the failure load.

2 F

s EQ. 5

nDH

[0131] The surface tension (g) of the photocurable formulation was measured by Equation 6 using a tensiometer (Kimble Chase 14818 Tensiometer, Cole-Parmer, Vernon Hills, IL, United States), where h is the distance between menisci of the tube and the capillary, r is the radius of the capillary, p is the density of the formulation, and g is the acceleration due to gravity. The density was measured by weighing 1 mL of each formulation in a pre-weighed microcentrifuge tube and dividing the value by the predetermined volume.

1

g =—hrpg EQ. 6

[0132] The inverse of Ohnesorge Number, Z value, was calculated to assess the printability of the different formulas engineered. Equation 7 defines the Z value, where a is the radius of the piezoelectric nozzle printing orifice used to dispense the formulations and p, y and h represent the density, surface tension, and viscosity of the photocurable formula, respectively. The viscosity of the formulations was measured with a rheometer (Discovery HR-2, TA Instruments, New Castle, DE, USA) using a 40 mm 2.016° cone and plate geometry with shear rate ranging from 10 to 100 Hz.

Imaging Gels with Scanning Electron Microscopy (SEM)

[0133] The microarchitecture of the gels was observed with a NOVA 230 NanoSEM scanning electron microscope. Images of lyophilized hydrophilic gels were taken, as well as cross-sectional images of hydrophobic gels.

Preform Tablet Fabrication and Characterization

[0134] The drug-containing bioinks were directly printed into tablet preforms that were fabricated by 3D printing (ProJet 660; 3D Systems, Inc.; Rock Hill, SC, USA). The printing materials consisted of calcium sulfate hemihydrate powder (VisiJet PXL Core; 3D Systems, Inc.; Rock Hill, SC, USA), and a liquid inkjet binder comprised of deionized water containing 5% ethanol and 0.25% Tween 80. The polypill preform tablet was designed with two separate chambers that could each hold up to 250 pL of ink and be assembled into a single tablet. The assembled dimensions were kept below the 22 mm maximum tablet size recommended by the Food and Drug Administration (FDA). Additionally, each chamber was independently modified to prevent absorption of the chambers respective drug-containing bioink into the preform tablet during printing by infusing the chambers with PEG (35 kDa) and submerging the tablet in an acetone solution containing 15% (w/w) PEG for 30 min at 55°C. Next, the well was brush-coated with Eudragit® E100 (Evonik, Essen, Germany) (polymethacrylate copolymer) dissolved in acetone at 20% (w/w). The chamber holding the hydrophilic formulation was infused with Eudragit® E100 dissolved in acetone at 10% (w/w). Surface morphology of the preform tablet was characterized by scanning electron microscopy (NOVA NanoSEM 230, FEI Co., Hillsboro, OR, USA). Drug Release Kinetics

[0135] A piezoelectric dispenser with a nozzle diameter of 80 pm (MJ-ABP-01 -080, MicroFab, Plano, TX, USA) was used to assess the droplet formation capability of the engineered bioinks. This dispenser was controlled with a microdispensing system (MD- E-3000, Microdrop, Norderstedt, Germany). The dispensing parameters used were 46 V, a 16 pm pulse width, and a frequency of 2000 Hz. The droplet formation process was captured with an analog camera (JAI CV-S3300), equipped with a lens (Edmund Optics, Barrington, NJ, USA). An LED light was connected to the microdispensing system, in order to control its strobe delay.

[0136] Lisinopril loaded hydrophilic bioink was dispensed in the bottom part of the polypill (250 pL) and exposed to visible light (120 mW/cm2) for 2 min, to induce gelation of the hydrogel precursor solution. Spironolactone loaded hydrophobic bioink was dispensed into the upper piece of the polypill (125 pL) and exposed to light for 1 min. Following the gelation of the bioinks, the pieces of the polypill were assembled to finalize the pharmaceutical product.

[0137] The tablets were placed into Uni-cassettes (Tissue-Tek) and immersed into beakers containing 500 mL of dissolution medium (monobasic potassium phosphate 1.053mM, pH of 2.5), conditioned at 37 °C and stirred at 60 rpm. Aliquots of 1 mL were taken after 0.5, 2, 4, 6, 8, 12, 18, and 24 h. The volume removed was replenished with fresh dissolution medium conditioned at 37 °C. The drug concentration in each aliquot was measured with an HPLC (Waters 2690 with a PDA 996 detector). The wavelength used to detect the APIs were 220 nm and 240 nm for Lisinopril and Spironolactone, respectively.

Statistical Analysis

[0138] Statistical analysis was performed with GraphPad Prism software (GraphPad Software, Inc., San Diego, CA). Statistical significance was assessed using single factor ANOVA test with a Tukey post-test and 95% confidence interval. Bioink Characterization

[0139] A Hyaluronic acid is a natural glycosaminoglycan found in connective, neural, and epithelial tissue. The biocompatibility of hyaluronic acid hydrogels has been assessed in tissue engineering studies, where diverse cell types have been cultured in hydrogels for the formation of tissues and the study of biological processes. Moreover, hyaluronic acid photocurable formulations can polymerize under quick gelation times (Fig. 16). Lisinopril was dissolved in a hyaluronic acid based hydrophilic bioink at a concentration of 40 mg/ml_. The Lisinopril formulation was dispensed into a modified syringe (50 pL) and exposed to visible light at an intensity of 120 mW/cm2 for 2 min (Fig. 17). The storage modulus of the resulting hydrogel was quantified to assess the mechanical properties of the polymerized bioink, due to its viscoelastic property. Additionally, hydrogels with different drug concentrations (20 and 10 mg/mL) were polymerized to study the effect of drug load on the mechanical properties of this hydrophilic material (Fig. 18 (A)). The results indicate that this hydrophilic material has a low storage modulus due to its elevated water content and the low I/I/HANB (3%) utilized for its fabrication. The elevated water content of the hydrogel allows for the effective diffusion of the hydrophilic API out of the oral dosage form, given the dissolution of the preform tablet designed to disintegrate under acidic conditions similar to the ones found in the stomach. The hydrogels had an average G’ of 1003.86 Pa. Figure 18A indicates that drug load has no influence in the mechanical properties of the hydrogel, where larger drug concentrations had no impact over the G’ of the gels. A decrease in G’ was noticed on hydrogels loaded with Ropinirole at a concentration of 80 mg/mL. It can be stated that the G’ remains stable for this Lisinopril formulation at concentrations between 0 and 40 mg/mL, the maximum Lisinopril concentration achievable in the hyaluronic acid solution.

[0140] Spironolactone was chosen as the second model drug in this study due to its high hydrophobicity. The model drug was dissolved in a PEG based bioink specifically engineered for hydrophobic drugs, at a concentration of 20 mg/mL. 50 pL of formulation were pipetted into a modified syringe, the solution was exposed to light for 1 min (Fig. 17), and the tensile strength of the resulting gel was measured (Fig. 18B). Results show an average tensile strength for this material of 176.66 kPa. The typical tensile strength of pharmaceutical tablets is within the range of 1 and 10 MPa. The G’ obtained for this gel is below this range, and therefore, this material would benefit to be used in combination with a sturdy compartments, such as a preform tablet, that provides support and physical stability to the oral dosage form. Furthermore, the effect of drug concentration on the mechanical properties of the gel was studied by measuring the tensile strength of gels containing 100, 80, 40, and 20 mg/ml_. Figure 18B shows that drug concentration had no impact on the tensile strength of the material. This contrast with results shown in previous example, where a decrease in tensile strength was observed with increasing Naproxen and Ibuprofen concentrations. This divergence is likely due to the lower I/I/PEGDA value used in this formulation (30%). These results indicate that softer materials conformed of photo-polymerized bioinks, such as the hyaluronic acid hydrogel, tend to have a steady mechanical stability when exposed to increasing drug concentrations. Stronger gels can experience significant differences in mechanical properties (Fig. 19).

[0141] SEM imaging was performed on both gels to observe the microarchitecture of the polymerized structures. Figure 20 shows a porous microarchitecture in both gels, allowing for the effective release of the dissolved API within them. The wrinkles observed in the hydrophilic gel (Fig. 20A) are a consequence of the lyophilized and dehydrated nature of the sample tested.

Droplet Formation

[0142] To study the droplet formation ability of these bioinks, the inverse of the Ohnesorge number, denominated as Z value, was calculated (Equation 6). This dimensionless number considers the inertia and surface tension forces of a fluid over its viscosity forces to define its droplet formation ability. The orifice radius of the nozzle used for the inkjet printing of the fluid is also a factor taken into consideration within this number. Z values between 4 and 14 are considered printable fluids. Values above 14 typically exhibit the formation of satellite droplets, whereas values below 4 present strong viscous forces. The viscosity, surface tension, and density of the bioinks was quantified, in order to determine their Z value. Table 1 shows the results obtained for these parameters at room temperature and the Z value for the two bioinks utilized in this study. The hydrophilic bioink experienced a higher viscosity value (9.83 cP), resulting in a lower Z value than the hydrophobic formulation. The later one had lower viscosity and surface tension parameters (4.88 cP and 31.41 mN/m, respectively), resulting in a higher Z value of 10.52. Flowever, both formulations fell within the defined range for printable fluids as depicted in Figure 21 and Figure 22, where the droplet formation sequence of these bioinks can be observed.

Table 1. Physical properties and Z value of formulated bioinks.

_R . . . r P y h ₇

(mm) (kg/m ³ ) (mN/m) (mPa ^* s)

Hydrophilic i 0.08 1022.27 57.76 9.83 6.99

Hydrophobic j 0.08 1048.00 31.41 4.88 1Q.S2

Preform Tablet Characterization

[0143] Calcium sulfate hemihydrate is clinically used in the preparation of plaster of Paris, which is used for casts that immobilize fractures, and is not used in tablet formulations. Calcium sulfate dihydrate, however, has been commonly used in pharmaceutical applications, and the dihydrate is formed when hemihydrate is mixed with water. In this example, water was used as the liquid binder during the fabrication of the perform tablets via 3D printing (Fig. 23). Upon contact with the powder, water causes the dissolution of the calcium sulfate hemihydrate and recrystallization of the dihydrate form. SEM analysis (Fig. 24A) shows that pores exist within the uncoated preform tablet wall. These pores negatively impacted the performance of tablets during printing of the bioink. Specifically, the porosity in the preform tablet allowed both the hydrophilic and hydrophobic bioinks to soak into the preform tablet during printing, which not only weakened the preform tablet, but also negates the advantages of using 3D printing for pharmaceutical applications, such as control over drug positioning (pictures not shown). To fill the pores, two different coatings were used depending on the ink being used for printing. For the hydrophilic bioink, the preform tablets were soaked in Eudragit® E100 (Fig. 24B). For the hydrophobic bioink, the preform tablets were first soaked in a high- molecular weight PEG (35 kDa) solution. Fligh-molecular weight PEG was selected because it is immiscible with the low- molecular weight PEGDA in the bioink (Fig. 24C). Additionally, a thin coating of Eudragit® E100 was added to the preform tablet well to further inhibit the absorption of the bioink during printing. SEM analysis shows that the polymeric coating fills the pores of the preform tablet (Fig. 24D). Polypill Dissolution Test

[0144] Hyaluronic acid based hydrophilic bioink was loaded with Lisinopril at a concentration of 40 mg/mL. 250 pL of this formulation were dispensed into the bottom compartment of the preform tablet and further exposed to visible light for 2 min, to induce gelation of the photocurable bioink. Likewise, the PEG based hydrophobic bioink was loaded with Spironolactone at a concentration of 20 mg/mL. 125 pL of this formulation were loaded into the top compartment of the preform tablet and exposed to visible light for a period of 1 min (Fig. 25). Once the bioinks were polymerized, the two compartments were attached and the small cap was placed to seal the top compartment, completing the oral dosage form. The tablet was immersed in a beaker containing 500 mL of dissolution medium, conditioned at 37 °C and stirred at 60 rpm. Aliquots were taken after 0.5, 2, 4, 6, 8, 12, 18, and 24 h of dissolution and their drug concentration was assessed through HPLC analysis. The results obtained show a dual sustained release of Lisinopril and Spironolactone in a period of 24 h (Fig. 26). The preform tablet dissolved almost in its entirety with the exception of the lower part of the top compartment, exposing completely the gels to the dissolution medium (Fig. 27). Lisinopril experienced faster drug release kinetics, when compared to Spironolactone. This result can be explained by the differences within the microarchitecture and composition of the gels. The hydrophilic formula has over 90% of water content, facilitating the diffusion of Lisinopril, a hydrophilic compound, into the dissolution medium. Moreover, the hydrogel has a I 1/HANB of only 3%, allowing small molecules to easily diffuse through the polymerize matrix. The hydrophobic formulation has a higher polymeric content ( 1 1/PEGDA = 30%) resulting in a mesh size of ~ 11 A, based on data shown in the previous example (Table 1 ). Naproxen and Ibuprofen have a hydrodynamic radius of 3.77 A and 6.80 A, respectively, and molecular weights of 230.26 Da and 206.29 Da. It can be hypothesized that the hydrodynamic radius of Spironolactone is close to the mesh size of the polymerized hydrophobic gel (11 A), since it has a significantly higher molecular weight than Naproxen and Ibuprofen. This characteristic would explain the slower release profile observed with Spironolactone, due to an impaired diffusion of the molecule through the gel matrix. The use of a higher PEGDA molecular weight for the fabrication of the gel could result in larger mesh sizes and consequently, enhanced drug release kinetics.

[0145] The dual release of these APIs for the treatment of hypertension demonstrates the use of inkjet printing for the fabrication of combination therapies. Moreover, it shows that the therapy could contain both, hydrophilic and hydrophobic compounds. This technology would be especially applicable towards drugs that achieve their pharmacological effect at low dosages and could be targeted towards the development of oral dosage forms for children, who require small dosages not always commercially available. Moreover, children experience drastic changes in metabolism that affect the dosage needed to achieve a given target pharmacological effect.

DOCTRINE OF EQUIVALENTS

[0146] While the above description contains many specific embodiments of the invention, these should not be construed as limitations on the scope of the invention, but rather as an example of one embodiment thereof. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their equivalents.