Fatty acid-modified poly(glycerol adipate) microparticles for controlled drug delivery

Abstract

Poly(glycerol adipate) is a new biodegradable polyester and a promising alternative to the commonly used PLA and PLGA. The free hydroxyl groups of the PGA backbone allow the conjugation of fatty acids and therefore, enable the synthesis of versatile FA-PGAs with tunable properties. Depending on the fatty acid (i.e. stearic and behenic acid) and the substitution degree, it is possible to adjust the physicochemical properties. Different FA-PGAs were investigated regarding their suitability to form solid microparticles by DSC, contact angle and oscillatory rheology measurements. Dibenzoyl Thiamine (DBT), a lipophilic drug with high potential for the prophylactic treatment of cleft lip and neuroprotective activity, was incorporated in the microparticles. In order to characterize the microparticles, laser diffraction analysis, SEM and XRD measurements were conducted and drug loading, as well as encapsulation efficiency, were determined. In addition, in-vitro release experiments were carried out. Due to the various possibilities to adjust the properties of the polymer, these FA-PGA microparticles have the potential to improve controlled drug delivery and to be a useful alternative to PLA and PLGA.