Comparative study of aqueous dispersion of different types of polymers on release behavior of salbutamol sulphate from coated pellets

The present study was designed to investigate the effect of different types of coating polymers such as Eudragit RL 30D, Eudragit RS 30D, Eudragit NE 30D, Surelease, and Kollicoat SR 30D on physical properties and release pattern of salbutamol sulphate (SS) pellets which were prepared by Extrusion-Spheronization technology. All the polymers used in coating solution were in aqueous dispersion form where Surelease was 25% aqueous dispersion and rest of the polymers was 30% dispersion. Surface morphology of the coated pellets was examined by Scanning Electron Microscope (SEM). All the pellets were of white to off-white color and spherical in shape. There was no marked difference in the values of % yield, loss on drying (LOD), % potency, and bulk density of the coated pellets from polymer to polymer. But a significant difference was found in % friability and % drug release. % Friability value was found maximum (0.59%±0.01) for Eudragit NE 30D and was minimum (0.0.12%±0.08) for Eudragit RL 30D. After 10 hours of dissolution in distilled water, almost same amount of drug was released from the pellets coated with the coating polymers. But considering first hour of dissolution, surelease showed more sustaining behavior than all the polymers. After 1 hour dissolution, only 12% of drug was released in case of surelease where as this was 80%, 83%, 63%, and 26% for Eudragit RL 30D, Eudragit RS 30D, Eudragit NE 30D, and Kollicoat SR 30D respectively.