Novel drug delivery system for lipophilic therapeutics of small molecule, peptide-based and protein drugs.

Effective drug delivery systems for biopharmaceuticals, such as proteins, peptide-based drugs, and vaccines still present major challenges. A procedure has been developed whereby human serum albumin (HSA) can be used as a delivery vehicle for these biomolecules exploiting its role as main fatty acid carrier. Using essentially fatty acid free HSA (HSAff) it is possible to form stable complexes with lipidic chain compounds (lipo compounds). Several lipo compounds have been used to develop this system, a novel antimicrobial lipopeptide and γ-amino-n-butyric acid, GABA, conjugated with an alkyl chain, lipo-GABA, in both cases C8 and C14 alkyl chain lengths were evaluated. The HSA-lipo complex had a mutual stabilizing effect on both the HSA and the lipo compound. The protease enzyme study showed that the alkyl chains of these lipo compounds bound to HSAff confer biostability to HSAff. With the antimicrobial lipopeptide, there was enhanced activity with HSAff formulation suggesting increased biostability and bioavailability of compounds. These finding allowed us to propose a simple and effective way of delivering lipo compounds using fatty acid free HSA as the carrier.