Abstract
Author(s): G. Ramakrishna*, B. Madhavarao, D.Srinivasa Rao andS.Ramu
Floating Drug Delivery System (FDDS) appears to be one of the promising GRDS. FDDS isbeneficial which shows a better gastric retention and increase the efficiency of the medical treatment.Oral dosage has really progressed from immediate release to delayed release to sustained release and site-specific delivery.The design of oral drug delivery systems (DDS) should be primarily aimed to achieve more expectable and increased bioavailability.This is achieved by better control of plasma drug levels with less frequent self-administered dosing yielding constant infusion of drug. The present study deals with the formulationand evaluation of cimetidine floating matrix tablets. Gastric floating drug delivery systems (GFDDS) offer numerous advantages over other gastric retention systems.Multiple dosing of Cimetidine is required for effective treatment leading to therapeutic fluctuations; thus a sustained release dosage form of Cimetidine is suitable. The absolute bioavailability of the Cimetidine is found to be 35% due to site specific absorption.Different polymers have been evaluated in the design of gastric floating drug delivery. In the present investigation two different polymers are used for the matrix formation, HPMC is a very good vehicle for floating tablets design and Guar gum is also selected as it is a natural vegetable gum which is considered as GRAS (generally regarded as safe) by FDA they selected for design of effervescent gastric floating matrix tablets of Cimetidine. The concentration of sodium bicarbonate and its effect on the floating behaviourand drug release was studied on polymer concentration. Effervescent gastric floating matrix tablets were prepared by wet granulation method. The tablets were designed to release the total dose of the drug over a period of 12±1 hours.Uniformity of weight hardness, friability and % assay of all the prepared ten formulation were found within the official and fixed limits. Floating lag time of the table’s decreases which increase in sodium bicarbonate, concentration helps to produce carbon dioxide gas which is entrapped within the hydrophilic matrices leading to increases in volume of dosage form resulting in lowering the density which helps the table to float. Due to the high viscosity of HPMC and Guar gum prevent the entry of media into the matrix and prolongs the total floating time up to 12 hour for all the batches. F5 formulation show shortest floating lag time when compared to other formulation