Monitoring thermal, structural properties, methotrexate release and biological activity from biocompatible spray-dried microparticles

Abstract

In this study, small-sized biodegradable and biocompatible spray-dried poly (lactic acid) (PLA) microparticles were produced and their structural and thermal properties were monitored for evaluating their influence in the release of the methotrexate (MTX). The physicochemical properties of microparticles containing different drug/polymer ratios (1:10, 2:9 and 1:3 m m−1) were evaluated using scanning electronic microscopy images, drug-loading efficiency, FT-IR spectroscopy, differential scanning calorimetry, thermogravimetry and X-ray diffraction analyses. The in vitro drug release and cytotoxicity assays assessed their performance as a drug delivery system. The particles exhibited excellent physicochemical aspects, such as spherical, small size and uniform particles with high drug-loading efficiency. The FT-IR, thermal and structural properties demonstrated that the drug is amorphously dispersed into the polymeric matrix. Mathematical modeling showed the sustained drug release for all prepared particles. In addition, in vitro cytotoxicity tests demonstrated the biocompatibility of spray-dried PLA microparticles and desired prolonged MTX release with efficient biological activity compared to free drug. Therefore, the results demonstrated an efficient and promising drug delivery system for parenteral or pulmonary in vivo application against the cancer.