Design, Development and Evaluation of Gastroretentive Drug Delivery System of Antacids

Magaldrate is an antacid have been widely used in the treatment of various gastric and duodenal disorders such as heartburn, reflux esophagitis, acid indigestion, gastritis, sour stomach, upset stomach, irritable stomach, gastric and duodenal ulcers. The conventional antacids dosage forms have a short duration of action which is about 2-3 hours due to gastric emptying process. A gastroretentive dosage form of antacid is needed since the healing of gastric ulcers occurs when gastric pH is kept above 3-4 during 24 hours. The present study was aimed at developing Gastro retentive bilayer drug delivery systems containing Magaldrate to minimize the side effect, improve the prolongation of action, to reduce the frequency of drug administration. A wet granulation technique was used to formulate 9 batches. Superdisintegrants like Polyplasdone XL-10, Ac-Di-Sol, and sodium starch glycolate was used for immediate release layer and HPMC K4 M, Ac-Di-Sol and lactose like polymers were used in floating layer. Preformulation studies were carried out to optimize the ratios required for various grades of polymers. The prepared floating tablets were evaluated for hardness, weight variation, thickness, friability, drug content uniformity, buoyancy lag time, total floating time, water uptake (swelling index), and in vitro dissolution studies. Successful formulation was developed having floating lag time as low as 30 sec and drug release was sustained up to 12 hrs. A biphasic drug release can be obtained by using bilayer tableting technology which involved compression of immediate and sustained release layer together. Bilayered floating tablets with release characteristics offer critical advantages such as, site specificity with improved absorption and efficacy. This technology can be inculcated to various medicaments which have stomach as the major site of absorption. 
Keywords: Magaldrate, Antacid, Gastroretentive dosage form, Bilayer floating tab, Superdisintegrant