Evaluation and optimizations of Ophthalmic preparation
1. INTRODUCTION 1.1 ANATOMY AND PHYSIOLOGY OF THE EYE Eyes are most marvellous sense organs as they make us aware of variousobjects all around us, nearly and far away. Eyes are nearly spherical in shape except that its front portion i.e., transparent cornea bulges a bit forward. The human eye is achallenging subject for topical administration of drugs. The eye is one of the mostdelicate and yet most valuable of the sense organs. The eye is protected by theeyelashes, eyelids, tears and blinking. The eyelashes catch foreign materials as theblink reflex prevents injury by closing the lids, blinking occurs frequently duringwaking hours to keep the corneal surface free of mucous and moistened by the tearssecreted by the lacrimal glands. The normal volume of tears in the eye is 7 µl whereas a non-blinking eye can accommodate a maximum of 30 µl of fluid. Blinking eyescan hold only 10 µl, excessive liquids, both normally produced and externa...