Controlled release calcium silicate based floating granular delivery system of ranitidine hydrochloride

The objective of the present investigation was to prepare and evaluate floating granular delivery system consisting of (i) calcium silicate (CS) as porous carrier; (ii) ranitidine hydrochloride (RH), an anti-ulcer agent; and (iii) hydroxypropyl methylcellulose K4M (HPMC) and ethylcellulose (EC) as matrix forming polymers. The effect of various formulation and process variables on the particle morphology, particle size, micromeritic properties, percent drug content, in vitro floating behavior, and in vitro drug release from the floating granules was studied. The scanning electron microscopy (SEM) of granules revealed that that more pores of CS in secondary coated granules (SCG) were covered by the polymer film than those in primary coated granules (PCG). The formulation demonstrated favorable in vitro floating and drug release characteristics. The in vivo evaluation for the determination of pharmacokinetic parameters was performed in albino rats. Higher plasma concentration was maintained throughout the study period from the floating granules of RH. The enhanced bioavailability and elimination half-life observed in the present study may be due to the floating nature of the dosage form. The results suggested that CS is a useful carrier for the development of floating and sustained release preparations.