Preliminary Investigation of Improved Solubility of Nifedipine by Co Processing with Vinylcaprolactam/Vinylacetate/PEG_(6000) copolymer Through Spray Dried Solid Dispersions

摘要

Poorly soluble drug nifedipine was co-processed through spray-drying with poly (vinyl caprolactam-co-vinyl acetate-co-ethylene glycol) (PVCVAEG). The obtained particles were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), infra-red spectroscopy (IR), optical and electronic microscopy. Dissolution kinetics was evaluated and compared to unprocessed and processed samples. Spray-drying produced smooth spherical particles. Crystallinity of the co-processed nifedipine and polymeric solubilizer was reduced as showed by XRD and DSC. No specific interaction between nifedipine and the polymeric solubilizer could be observed by IR or DSC. Dissolution kinetics of the co-processed samples was improved as compared to original nifedipine crystals and to spray-dried plain nifedipine particles. Solubility parameters showed that nifedipine had strong probabilities of being miscible and to dissolve in the polymeric carrier. Results point to the formation of solid dispersion-like systems which explain the improved solubility profiles.