Colon specific chronotherapeutic drug delivery for nocturnal asthma: Eudragit S-100 coated calcium alginate gel beads-entrapped salbutamol sulphate

Abstract

Eudragit S-100 coated calcium alginate gel beads entrapped salbutamol sulphate as a model drug has been investigated in the present study. The microspheres were evaluated for the drug content, drug entrapment efficiency, particle size, surface morphology and in vitro drug release. Drug-polymer compatibility was investigated by FTIR spectroscopy and differential scanning calorimeter (DSC). Encapsulation efficiency was found to be high when cross-linking time is less. Scanning electron microscopy revealed that the microspheres were spherical and had a smooth surface. The drug dissolution study performed simulating gastrointestinal pH variance showed a burst release calcium alginate gel beads in initial hour, whereas eudragit S-100 coating allowed producing systems of controlled release system. The drug release was found inversely proportional to sodium alginate concentration, CaCl2 concentration and eudragit S-100 concentration.