Anaagat*, Shashi Shekhar Tripathi, Pravin Gupta, Rahul Dev, Ravi Prakash
Sir Madanlal Institute of Pharmacy AalampurHauz, Etawah-206001, U.P., India
Gastroretentive Drug Delivery Systems (GFDDS) are retained in the stomach for a longer time and assist in improving the oral controlled delivery of drugs that have an absorption window in the particular region of the GI tract as well as for controlling the release of the drug having site-specific absorption limitation. Ranitidine hydrochloride is an antiulcer drug and works on H2-receptor mainly in stomach. The primary absorption region of this drug is stomach. Since it is an antiulcer drug, it will be beneficial to retain the drug in gastric region. In the present work, an attempt was made to prepare GFDDS of Ranitidine HCl using different polymers by ionotropic gelation method with sodium alginate, pectin and HPMC as polymers, and CaCO3 as the buoyancy providing agent. All the prepared HBS formulations were evaluated for size, morphology, drug content, drug-polymer interaction, in-vitro floating studies, in-vitro drug release and short term stability studies. IR spectroscopic studies indicated that there was no incompatibility between drug, polymer and co-excipients. The drug-polymer ratio, type of polymer, and ratio of buoyancy providing agent were found to influence the drug release and floating properties of the prepared GFDDS. Decrease in polymer concentration and CaCO3 proportion was found to enhance the drug release from the GFDDS. The drug release was faster in case of GFDDS containing pectin (3A-C) when compared to GFDDS prepared with HPMC (10A-C). The floating lag time was found to be more when the CaCO3 ratio was less. Addition of CaCO3 as buoyancy providing agent showed considerable reduction in the floating lag time. The in-vitro dissolution profiles of all the GFDDS formulations of Ranitidine HCl were controlled for a period of more than 14 hours. The drug release data showed a good fit to Higuchi model indicating that diffusion is the predominant mechanism controlling the drug release. Among the various GFDDS formulations studied, formulation 3C containing drug-polymer ratio (1:1) prepared with pectin showed promising results releasing ≈ 88% of the drug in 14 hours with a floating lag time of 1 sec and floating time of more than 24 hours.
Keywords: HPMC, Ranitidine hydrochloride, Drug-polymer Interaction, GFDDS.