Ophthalmic drug delivery is one of the most interesting and challenging endeavors faced by the pharmaceutical scientists. Insitu gels are one of the upcoming classes of polymer based drug delivery system. Insitu gel implies that formulation is in solution form at normal condition and upon instillation in eye transformed into gel.This book is significant for UG, PG students and researcher also. A small part was previously published in TPI journal.Book facilitates a quick review of ophthalmic drug delivery and incorporates practical aspects of formulation and development. Book is first to present a systematic introduction to ophthalmic drug delivery including anatomy and physiology of eye, objectives, need for present investigation, basic concepts, literature review, development and optimization of Insitu gel by applying factorial design and formulation of various batches using pH sensitive polymers. This book is comprehensive, uniform guide for review, formulation, optimization and characterization of Insitu ophthalmic gel and its application. The book will be of value to person with an interest in novel ophthalmic formulation and to counteract ophthalmic challenge