Preparation and Characterization of Drug-Loaded Phthalic Anhydride Based Hyperbranched Polyesteramide Microspheres

Abstract

This work was aimed to study the controlled drug delivery behavior of phthalic anhydride based hyperbranched polyesteramide (PA-HBPEA) synthesized by self-polycondensation method under nitrogen atmosphere. Drug-loaded microspheres were prepared by oil-in-water (o/w) emulsion solvent evaporation methodology using acetaminophen as a model drug and PA-HBPEA as the matrix. The polymer and microspheres were characterized by UV-Vis, FTIR and 1H NMR spectroscopy techniques. The morphology was observed by scanning electron microscopy (SEM) and optical microscopy. The drug loading capacity, drug entrapment efficiency, and percentage drug release were also measured by the UV-Vis spectroscopy. FTIR and NMR results confirmed the formation of drug-loaded PA-HBPEA microspheres. An in-vitro drug release study was carried out to understand the nature of transport of drug-containing solution through the polymeric material. The potential of high content of HBPEA formulation (HBPEA-M2) was controlled drug release more (up to 60.3%) than HBPEA-M1 (up to 76.8%) with acidic and phosphate buffer medium at 37°C at various time intervals. Drug release kinetics of zero order Higuchi and Korsmeyer – Peppas models were found to be satisfactory with exponent n > 0.6, which shows non-fickian diffusion release. The average size of microspheres was found to be 50 μm. In-vitro drug release data showed that HBPEA has potential of controlled drug release in phosphate buffer medium.