A Study of certain Formulations of pharmaceutical Gels

Antihistamines of various types have gained wide spread use allover the world. They diminish and prevent several of the harmful pharmacological effects of histamine. Furthermore, many antihistamines have other pharmacological properties, largely independent of antihistamine activity, including anticho1inergic, antiadrena1ine and antihistamine effects. Antihistamines are widely included in many pharmaceutica1 formulations.Recently, gels are becoming more and more a series of derma to logical pharmaceuticals. In the present, work, gel bases from (carbopol 934, eudispert mv. methylcellulose, sodium carboxymethylcellulose , pectin, gelatin and glycerin of starch) have been selected as d topically applied dosage form in which was incorporated two antihistamine drugs, cyproheptadine hydrochloride and diphenhydramine hydrochloride. Both drugs have been long identified in the field of topical therapeutic application. The experimental work presented in this thesis is a contribution to the study gels as a semi-solid topically applied dosage form, and to the identification of the variables influencing the suitability and accept¬ability of this system in the field of application. The thesis comprises a study of the release, stability and bioavailability of different medicaments included in pharmaceutical gels. For this purpose the experim¬ental work in this study embraces the Following parts;PART (1)Formation and stability of cyproheptadine hydrochloride gels .PART (2)Formation and stability of diphenhydramine hydrochloride gelsPART (3):Bioavailability of cyproheptadine hyclrochloride and diphanhydramine hydrochloride from different gel bases.