received by the International Bureau on 20 May 2014 (20.05.2014)

The Claims:

1. A hydrophobic compound loaded surfactant-copolymer complex for sustained release of hydrophobic compounds comprising hydrophobic compound in the range of 0.1% to 10% (by weight), surfactant in the range of 0.1 to 30% (by weight) and mucoadhesive copolymer in the range of 0.1% to 30% (by weight) and remaining being a solvent, wherein the hydrophobic compounds are sustained release over a period of 13-23 hours.

2. The hydrophobic compound loaded surfactant-copolymer complex as claimed in claim 1, wherein said hydrophobic compound is selected from the group consisting of antibacterials, ointments, drugs, bioactives, perfumes, flavors, pesticides or combination thereof.

3. The hydrophobic compound loaded surfactant-copolymer complex as claimed in claim 1, wherein said surfactant is a nonionic surfactant.

4. The hydrophobic compound loaded surfactant-copolymer complex as claimed in claim 3, wherein said nonionic surfactant is selected from the group consisting of nonaoxyethylene-n-dodecyl ether (Ci₂E₉), polysorbate 20 (Tween 20), polysorbate 40 (Tween 40), polysorbate 60 (Tween 60), polysorbate 80 (Tween 80) or combination thereof.

5. The hydrophobic compound loaded surfactant-copolymer complex as claimed in claim 1, wherein mucoadhesive copolymer used is poly (maleic acid-alt- vinyl methyl ether).

6. The hydrophobic compound loaded surfactant-copolymer complex as claimed in claim 5, wherein mucoadhesive copolymer poly (maleic acid-alt vinyl methyl ether) is not limited to copolymer of methyl vinyl ether and maleic acid but also includes its anhydride, alkali or alkaline salts, CI to C6 alkyl esters, free acids or like thereof

7. The hydrophobic compound loaded surfactant-copolymer complex as claimed in claim 1 , wherein the weight ratio of surfactant to copolymer is 1 : 1.

8. The hydrophobic compound loaded surfactant-copolymer complex as claimed in claim 1, wherein hydrophobic compound is in the range of 1 to 50% by weight of the surfactant-copolymer complex.

9. The hydrophobic compound loaded surfactant-copolymer complex as claimed in claim 1 , wherein said solvent is selected from the group consisting of distilled deionized water, glycerine, ethanol or combination thereof.

10. A process for the preparation of hydrophobic compound loaded surfactant-copolymer complex as claimed in claim 1 comprising the steps of:

a) dispersing mucoadhesive copolymer in solvent in a ratio ranging between 1% to 40% to obtain turbid solution of mucoadhesive copolymer;

b) dissolving the hydrophobic compound in surfactant in a ratio ranging between 1% to 50% (weight of hydrophobic compound by weight of the surfactant) at temperature in the range of 10°C to 80°C to obtain hydrophobic compound- surfactant mixture;

c) adding hydrophobic compound-surfactant mixture as obtained in step (b) in water to obtain surfactant solution loaded with hydrophobic compound;

d) adding surfactant solution loaded with hydrophobic compound as obtained in step (c) to the turbid solution of mucoadhesive copolymer as obtained in step (a) to obtain hydrophobic compound loaded surfactant-copolymer complex.

1 1. The process according to claim 10, wherein the said surfactant is nonionic surfactant selected from the group consisting of nonaoxyethylene-n-dodecyl ether (Ci₂E₉), polysorbate 20 (Tween 20), polysorbate 40 (Tween 40), polysorbate 60 (Tween 60), and polysorbate 80 (Tween 80) or combination thereof.

12. The process according to claim 10, wherein the said mucoadhesive copolymer is poly (maleic acid-alt vinyl methyl ether).

13. The process according to claim 10, wherein poly (maleic acid-alt vinyl methyl ether) used is not limited to mucoadhesive copolymer of methyl vinyl ether and maleic acid but also includes its anhydride, alkali or alkaline salts, CI to C6 alkyl esters, free acids or like thereof.

14. The process as claimed in claim 10, wherein solvent used is selected from the group consisting of distilled deionized water, glycerine, ethanol or combination thereof.

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