Formulation and Evaluation of Chitosan Based Buccal Patch of Granisetron Hydrochloride

Granisetron hydrochloride is most commonly used as an antiemetic agent in treatment associated with cancer chemotherapy induced nausea and vomiting. If the dosage form is designed in sustain release it provide more advantage for the antiemetic therapy. The purpose of this research was to study mucoadhesive buccal patches of Granisetron hydrochloride using the bioadhesive polymers chitosan and sodium alginate. Patches containing chitosan in 1.5%w/v and sodium alginate 2%w/v had maximum percentage of in vitro drug release and ex vivo drug permeation upto 8 hr. The swelling index was proportional to chitosan and sodium alginate content. The surface pH of all patches was found to be satisfactory (7.0 ± 1.5), close to neutral pH; hence, buccal cavity irritation will not be a problem with these patches. The mechanism of drug release was found to be Higuchi (matrix). The formulation F6 was optimized based on good bioadhesive strength (326.96±0.99 N/M) and sustained in vitro drug release (95.81% ± 3.21% for 8 hr), ex vivo permeation (96.59% ± 3.69% for 8 hr). INTRODUCTION: There is need to develop a dosage form that bypasses first pass metabolism and GI degradation. Oral cavity provide route for the administration of therapeutic agent for local as well as systemic delivery, so that first pass metabolism and GI degradation can be avoided. The buccal route was chosen because of its good accessibility, robustness of epithelium, facile removal of the dosage form, relatively low enzymatic activity and natural clearance mechanism for elimination of the drug from buccal area, satisfactory patient acceptance and avoiding the hepatic first pass metabolism . GRA.HCl is rapidly absorbed from the GIT, but later it is subjected to extensive first pass metabolism. In healthy volunteer, half-life of the drug is reported to be about 3-4 hr. Therefore, current GRA.HCl treatment generally involve oral dose of 1-2 mg, one hour before start of chemotherapy treatment, then 2 mg daily in 1-2 divided doses upto 4 days. Also a single 3 mg IV dose of GRA can be administered, repeated if necessary with a maximum daily dose of 9 mg 2, . But there are some limitations for GRA.HCl when given by oral route. If patient started vomiting, oral route cannot be used and some alternative routes of administration like parenteral, transdermal, rectal or buccal administration are needed. Amongst all, parenteral require skillful person as well as hospitalization. When we consider rectal route, it take lag time to show antiemetic action and is quite unacceptable route by the patient.