Development of Triprolidine-Hydrochloride-Loaded pH-Sensitive Poly(Acrylamide-co-Acrylamidoglycolic Acid) Co-Polymer Microspheres: In Vitro Release Studies

Abstract

Poly(acrylamide-co-acrylamidoglycolic acid) co-polymeric microspheres cross-linked with N,N-methylene bisacrylamide have been prepared by free radical emulsion polymerization using varying amounts of acrylamide (AAm), acrylamidoglycolic acid (AGA) and N,N-methylene bisacrylamide (NNMBA). Triprolidine hydrochloride (TPH) was loaded into these microspheres during in situ polymerization. The microspheres have been characterized by Fourier Transform Infrared Spectroscopy (FT-IR), to confirm the formation of co-polymer. Differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) were used to understand the drug dispersion in these microspheres. Scanning electron microscopy (SEM) was used to assess the surface morphology of particles prepared. In vitro release of TPH has been studied in terms of composition, amount of cross-linking agent and amount of TPH in the microspheres. The microspheres with different co-polymer compositions have been prepared in yields ranging from 75–80%. DSC and XRD indicated a uniform distribution of TPH particles in microspheres, whereas SEM suggested the formation of distinct spherical shape microspheres. The in vitro drug release indicated release kinetics depending upon co-polymer composition, amount of cross-linking agent used and amount of TPH present in the microspheres. Prolonged and controlled release of TPH was achieved when drug was loaded in the co-polymer and the drug was released in a controlled manner for up to 12 h.