Entrapment or microencapsulation of drugs in a polyhydroxyalkanoate formed by enzyme synthesis

A process for producing drug entrapped granules comprising:

• dissolving a hydrophilic drug in an aqueous medium,
• synthesising a polyhydroxyalkanoate homopolymer or copolymer in said aqueous medium by in vitro enzyme polymerization of at least one hydroxyalkanoate Coenzyme A monomer produced by reaction of a carboxylic acid group of a hydroxyalkanoic acid with a thiol group of Coenzyme A, said at least one monomer being a precursor of said polyhydroxyalkanoate, with formation in said aqueous medium of particles of the synthesized polyhydroxyalkanoate,
• allowing said particles to coalesce to microporous granules having aqueous medium containing dissolved hydrophilic drug entrapped in micropores of the granules,
• recovering said microporous granules with said aqueous medium and dissolved hydrophilic drug entrapped in the micropores of said microporous granules, and
• drying said granules with said entrapped hydrophilic drug.

A process for producing a microencapsulated lipophilic drug comprising:

• dissolving a lipophilic drug in an edible oil, adding an aqueous medium and forming an oil-in-water emulsion comprising droplets of said oil containing the dissolved lipophilic drug, in an aqueous phase,
• synthesizing a polyhydroxyalkanoate homopolymer or copolymer in said aqueous phase by in vitro enzyme polymerization of at least one hydroxyalkanoate Coenzyme A monomer produced by reaction of a carboxylic acid group of a hydroxyalkanoic acid with a thiol group of Coenzyme A, said at least one monomer being a precursor of said polyhydroxyalkanoate, with formation in said aqueous phase of microcapsules having a capsule wall of the synthesized polyhydroxyalkanoate entrapping a fluid core comprising said oil with said drug dissolved therein,
• recovering said microcapsules, and
• drying said microcapsules with said fluid core therein.