This invention relates to a novel, solid composition in the form of capsules or tablets containing a swelling pharmaceutically active compound and having im¬ proved disintegration time and dissolution time.

BACKGROUND OF THIS INVENTION

When preparing pharmaceutical compositions, it is important to secure that the active ingredient is absorbed by the patient at a desired and convenient rate. For some medical treatments, a rapid rate of absorption is desired and for other treatments, a retarded rate of absorption is desired. Also, medicaments having both a rapid onset of action and a prolonged action are on the market.

The preparation of a pharmaceutical composition containing a swelling pharma¬ ceutical active compound may be difficult in that the swelling of the active com¬ pound may result in a too long disintegration time and a too long dissolution time. One way of solving such problems is to add a disintegrant such as sodium carboxymethylcellulose and starches. Another way of solving such problems is to reduce the particle size of the active compound.

Until now, these known, general methods have proved unsuccessful.

For purposes deviating substantially from the object of this invention, the addition of carbohydrates to pharmaceutical compositions has been suggested. The pharmaceutically active compounds in these known compositions are sparingly soluble, non-swelling chemical compounds. Examples of such com¬ pounds are bendrofluazide Drug Dev.lnd.Pharm. 3 (1977), 439 et sea.), hydro- cortisone and prednisone (J.Pharm.Sci. 67 (1978), 979 et seg.), trimethoprim

(Pharm.Acta.Helv. 58 (1983), 62 et seg.), hydrochlorothiazide (Drug Dev.lnd.- Pharm. W (1984), 1709 et seg.), carbamazepine and nitrazepam (Drug Dev.lnd.- Pharm. H (1985), 1957 et seg.).

Pharmaceutical compositions containing sparingly soluble, non-swelling compounds are prepared by a complex melting procedure using two or more ingredients such as the active compound and the carbohydrate.

Pharmaceutical compositions having a retarded action are known. Such com¬ positions are prepared by adding a swelling compound such as hydroxymethyl- cellulose to the composition.

Solid pharmaceutical compositions containing a swelling ingredient as well as a polysaccharide such as starch or a disaccharide such as glucose or lactose are known. As far as we know, none af such known compositions are in the form of capsules or tablets.

In Martindale, The Extra Pharmacopoeia, 26 (1972), such compositions are described. At page 1077, Arabon containing ceratonia and starch is desribed. At page 1084, Metamucil containing Psyllium hydrophilic and dextrose is described. At page 1073, Methylcellulose granules containing methylcellulose and lactose is described. At page 1093, "Compound Tragacanth Powder" con¬ taining tragacanth, starch and sucrose is described. Arabon, Metamucil and "Compound Tragacanth Powder" are powders.

Methylcellulose granules are granules. In addition, these known compositions are either to be used locally or they are technical excipients which are not to be absorbed by the patient.

It is known from J.Pharm.Pharmac. 20 (1968), 228 S et seg., that "the disin- tegration times did not correlate with the dissolution times". In addition, it appears from the last-mentioned paper that the addition of sorbitol resulted in a substantially longer disintegration time. It is mentioned in Drug Dev.lnd.Pharm. 3 (1977), 439 et seg., that "decreasing the solubility of the diluent decreased the

disintegration time". Based upon this fact, the skilled art worker will draw the conclusion that increasing the solubility by adding a carbohydrate to a solid pharmaceutical composition will result in a composition having an increased disintegration time.

The use of haemoglobin compositions as a ferrous supplement to the diet of mammalian animals including man has been known for decades. Some haemo¬ globin compositions are solid compositions and other compositions are used in dissolved form.

When administering a solid haemoglobin composition, it is of the out- most importance to ensure that iron is released from the composition and thus is available for uptake by the patient. The hitherto known, solid haemoglobin compositions do not have a sufficiently short disintegration time and/or short dis¬ solution time. Hitherto, no solid haemoglobin compositions fulfilling the requirements concerning disintegration time and dissolution time stated in the Pharmacopoeias have been available.

One object of this invention is to make available a composition containing a swelling pharmaceutically active compound and having an improved disin¬ tegration time leading to a preparation with an improved dissolution time.

Another further object of this invention is to make available a com- position containing a swelling pharmaceutically active compound which com¬ position can be prepared by a relatively simple mixing procedure of the ingre¬ dients.

BRIEF DESCRIPTION OF THIS INVENTION

Surprisingly, it has been found that the presence of certain carbohydrates, i.e., mono-, di- or oligosaccharide or alcohols thereof, in a solid composition con¬ taining a swelling pharmaceutically active compound results in a composition

having the desired disintegration time and the desired dissolution time.

As explained above in relation with the background of this invention, mixtures with several sorts of carbohydrates are know. These mixtures are used for various purposes. However, there is nothing in the known art teaching or indication that exactly mono-, di- or oligosaccharide and alcohols thereof have this desired effect. As proved in the examples below, polysaccharides does not have the desired effect.

DETAILED DESCRIPTION OF THIS INVENTION

A swelling pharmaceutical active compound is a pharmaceutical compound which in water makes a highly viscous, gel-like structure acting as barrier to diffusion and wetting of the core of the solid.

In a preferred embodiment of this invention, the swelling pharmaceutical active compound is a macro-molecular compound. The molecular weight of the swelling pharmaceutical active compound could, for example, be above about 200, preferably above about 500, most preferred above about 1000.

As stated above, the swelling pharmaceutical active compounds are highly vis¬ cous in water. In a preferred embodiment of this invention, the swelling com¬ pound has a viscosity above about 5, preferably above about 15 cps, when measured in a solution containing 30 % (weight/weight) of the swelling com- pound or, if the swelling compound has a lower solubility, when measured in a saturated solution. For example, the viscosity of a 30 % (weight/weight) haemo¬ globin solution is about 24 cps.

The swelling pharmaceutically active compound may, for example, be haemo¬ globin, Ginko Biloba extracts, a glycosaminglycane or polysaccharides. Preferably, the content of the swelling pharmaceutically active compound

in the composition of this invention is in the range 30 - 90 %, preferably in the range 50 - 75 % (weight/weight).

In a preferred embodiment of this invention, the monosaccharide used is dex¬ trose. In another, preferred embodiment, the monosaccharide alcohol used is sorbitol, mannitol, xylitol, lactitol or maltitol, preferably sorbitol. In a still further embodiment of this invention, the disaccharide used is as sucrose, fructose or lactose, preferably sucrose. Preferably, the oligosaccharide used in the com¬ positions of this invention does not contain more than 10 monosaccharide units, more preferred not more than 5 units. Preferably, the content of the mono-, di- or oligosaccharide or an alcohol thereof in the composition of this invention is in the range 5 - 50 %, preferably in the range 10 - 40 % (weight/weight).

The compositions of this invention are prepared by simple mixing of the swelling pharmaceutically active compound and the carbohydrate. Before the mixing procedure, the swelling pharmaceutically active compound and/or the mono-, di- or oligosaccharide or the alcohol thereof may be present in granulate form. During the mixing process, also other excipients commonly used in the art may be added to the mixture. Examples of such additional compounds are other actives, buffering agents, stabilizing agents, lubricants, filling agents, diluents, disintegrating agents, humectants or binders.

In principle, the compositions of this invention are prepared analogously with the preparation of similar known compositions.

The solid compositions of this invention are capsules or tablets. The solid com¬ position may be uncoated, filmcoated or sugarcoated.

The compositions of this invention are used analogously with the use of similar known compositions.

The present invention is further illustrated by the following examples which, how¬ ever, are not to be interpreted limiting.

Example 1

a) The following ingredients were used: 350 mg of haemoglobin (spray- dried), 35 mg of glycerol (Ph.Eur.), 25 mg of ferrous fumarate, 66 mg of sucrose (Ph.Eur.), 5 mg of silicon dioxide, colloidal (Ph.Eur.) and 3 mg of magnesium stearate (Ph.Eur.).

Haemoglobin was granulated in a high-shear mixer with glycerol without contact with water. The rest of the components and the granulate were mixed in a double cone mixer. Tablets were compressed on a single punch tablet press to a tensile strength of 7 ± 1 kp.

Disintegration times were measured as described in Ph.Eur., 2nd Ed., V.5.1.1 (1986) using discs.

The disintegration time was found to be 55 minutes.

b) Using the same ingredients as described in Example 1a, with the pro¬ viso that no sucrose was added, a disintegration time of 105 minutes was ob¬ tained.

c) Using the same ingredients as first described in this example (1a), with the proviso that 66 mg of maize starch was used instead of 66 mg of sucrose, a disintegration time of 150 minutes was obtained.

The above, comparative examples shows the surprising effect of using sucrose (55 minutes) compared with not using sucrose (105 minutes) and substituting sucrose for starch (150 minutes).

Example 2

The following ingredients were used: 350 mg of haemoglobin (spray-dried), 35 mg of glycerol (Ph.Eur.), 25 mg of ferrous fumarate, 198 mg of sucrose (Ph.Eur.), 5 mg of silicon dioxide, colloidal (Ph.Eur.) and 3 mg of magnesium stearate (Ph.Eur.). The mixing, compression and test procedures were as de¬ scribed in Example 1.

The disintegration time was found to be 56 minutes.

Example 3

The following ingredients were used: 350 mg of haemoglobin (spray-dried), 35 mg of glycerol (Ph.Eur.), 25 mg of ferrous fumarate, 132 mg of sucrose (Ph.Eur.), 29 mg of sodium carboxymethylcellulose (USP), 5 mg of silicon dioxide, colloidal (Ph.Eur.) and 3 mg of magnesium stearate (Ph.Eur.). The mixing, compression and test procedures were as described in Example 1. The disintegration time was found to be 44 minutes.

Example 4

a) The following ingredients were used: 350 mg of haemoglobin (spray- dried), 35 mg of glycerol (Ph.Eur.), 25 mg of ferrous fumarate, 132 mg of man¬ nitol (Ph.Eur.), 5 mg of silicon dioxide, colloidal (Ph.Eur.) and 3 mg of mag¬ nesium stearate (Ph.Eur.). The mixing, compression and test procedures were as described in Example 1.

The disintegration time was found to be 56 minutes.

b) Using the same ingredients as described in 4a, with the proviso that 132 mg of maize starch were used instead of 132 mg of mannitol, a disintegration

time of 130 minutes was obtained.

c) If, additionally, 28 mg of sodium carboxymethylcellulose were added to the ingredients mentioned in Example 4b, also a disintegration time of 130 minutes was obtained.

The above, comparative examples shows the surprising effect of using mannitol (56 minutes) compared with substituting mannitol for starch (130 minutes), with and without the addition of sodium carboxymethylcellulose.

Example 5

The following ingredients were used: 350 mg of haemoglobin (spray-dried), 35 mg of glycerol (Ph.Eur.), 25 mg of ferrous fumarate, 132 mg of sorbitol (Ph.Eur.), 5 mg of silicon dioxide, colloidal (Ph.Eur.) and 3 mg of magnesium stearate (Ph.Eur.). The mixing, compression and test procedures were as described in Example 1.

The disintegration time was found to be 44 minutes.

Example 6

The following ingredients were used: 350 mg of haemoglobin (spray-dried), 35 mg of Glycerol (Ph.Eur.), 25 mg of ferrous fumarate, 132 mg of maltodextrin (Glucidex 19, Roquette), 5 mg of silicon dioxide, colloidal (Ph.Eur.) and 3 mg of magnesium stearate (Ph.Eur.). The mixing, compression and test procedures were as described in Example 1.

The disintegration time was found to be 56 minutes.

Example 7

The following ingredients were used: 350 mg of bovine haemoglobin (spray- dried), 42 mg of glycerol (Ph.Eur.), 6 mg of silicon dioxide, colloidal (Ph.Eur.), 132 mg of sucrose (Ph.Eur.), 28 mg of sodium carboxymethylcellulose (USP), 25 _s mg of ferrous fumarate and 3 mg of magnesium stearate (Ph.Eur.).

Haemoglobin was granulated in a high-shear mixer with glycerol without contact with water. Silicon dioxide, colloidal, sucrose and sodium carboxymethylcellulose were mixed with the granulate in the high-shear mixer and sieved. Ferrous fumarate and magnesium stearate were mixed with the granulate in a double o cone mixer. Tablets were compressed on a rotary tablet press to a tensile strength of 7 ± 1 kp.

Disintegration times were measured as described in Ph.Eur., 2nd Ed., V.5.1 (1986) using discs.

The disintegration time was found to be 37 minutes. s The dissolution time (ferrous) was measure as described in Ph.Eur., 2nd

Ed., V.5.4 (1991). Test results are given in Figure 1 showing the dissolution pro¬ file.

The dissolution profile, i.e., the percentage of iron dissolved in relation to the time from the start, is given in Table 1 below. In this table, also the dissolution 0 profile of the product described in Example 1c is given.

As appears from this table, the composition according to this invention (Example 7) has a substantial better dissolution profile than the composition not covered by the claims (Example 1c).

Percentage iron dissolved

Time, minutes example 1c example 7

0 0 0

10 8.3

20

30 20.3 44.1

45 69.2

60 85.0

80

90 48.5 95.6

120 64.4 98.5

150 78.0

180 87.7

240 94.6