Gastroretentive

Among the different routes of drug administration the oral route is most successful and popular. Dosage forms with a prolonged gastric residence and controlled drug delivery are called as Gastroretentive Drug Delivery System. Thus, these dosage forms significantly extend the period of time over which the drugs may be released in comparison to other Controlled Release Drug Delivery System. Different objectives that are to be achieved during development of gastro retentive drug delivery system are as it should increase bioavailability of drug, increase residence time of dosage form in stomach, achieve greater patient compliance by reducing frequency of dosing, better safety profile, achieve the improved economy of dosage form.This review covers major aspects of stomach anatomy and physiology, factors, rational, objectives, approaches, evaluation of gastroretentive drug delivery system.

Target drug delivery is beneficial for the delivery of pharmaceutical product to its appropriate site and with the resurgence in the use of herbal therapies as health care medication and this new field of drug delivery holds intensive research. The purpose of the current study was to design, gastroretentive  mucoadhesive tablets using powdered leaves of Murraya koenigii and to optimize  a product using natural gums and their combinations. The gastroretentive, boiadhesive drug delivery prolongs the residence time of the dosage form at the site of absorption and facilitates an intimate contact of the dosage form with the underline absorption surface and thus contribute to improve and/or better therapeutic performance of the drug and shows promising future in enhancing the bioavailability and specific needs by utilizing the physiochemical characters of both the dosage form and the mucosal lining Gastroretentive, mucoadhesive tablets using powdered leaves of Murraya koenigii were prepared using direct compression method and evaluated for parameters such as Weight variation, Hardness, Friability, Drug content, Swelling index, In –vitro drug release study, In – vitro and In – vivo mucoadhesive strength. Different types of natural gums such as Carbopol, Hydroxypropyl methylcellulose (HPMC) and a gas – generating agent (Sodium bicarbonate) were used. The investigation shows that the tablet composition and mechanical strength have the greatest influence on the floating properties and the drug release. With the incorporation of a gas – generating agent, along with the polymers, increased optimum floating (floating lag time to 30 minutes, and the duration of floating > 8 hours ). The drug release was also increased and was sufficiently sustained (more than 8 hours) and non –Fickian transport of the drug was confirmed.

Gastroretentive systems have the unique quality to remain in the gastric region for several hours. Due to this they prolong the gastric residence time of the drug significantly. Floating microspheres possess the advantage of better flowing properties attributed to the use of low density polymers. Clarithromycin is a broad-spectrum antibiotic and extensively absorbed orally. It is used in the eradication of H. Pylori infection combined with an acid suppressing agent. Clarithromycin floating microspheres were prepared using polymer Ethyl Cellulose in different concentrations by solvent evaporation method. The FTIR studies showed no interaction between drug and polymers. The floating microspheres were evaluated for angle of repose, percentage yield, particle size, SEM, buoyancy percentage, drug content, percentage drug entrapment, in-vitro dissolution studies, kinetics of drug release and stability studies. Formulation F3 was found to be the best formulation showing the highest degree of sustained release that is 73.86% at the end of 12 hours. Formulations were seen to follow zero order release profile and Korsemeyer-Peppas model was the best fitting model. Marginal changes were observed in the drug content, buoyancy time and In-vitro dissolution studies which are insignificant. Storage conditions were carried out at 40±20C/75±5%RH for 6 months.