An attempt has been made to formulate drug-free ophthalmic Þ lms by using different polymers in single use as well as in combinations for matrix system design for ocular use and to study the effect of various plasticizers on physicochemical characteristics and permeability of the resultant Þ lms. Drug-free Þ lms of hydroxypropyl methyl cellulose (HPMC), polyvinyl alcohol (PVA), hydroxypropyl cellulose (HPC), polyvinyl pyrrolidone (PVP), and Eudragit RL 100 polymers were prepared by the solvent casting method on a mercury surface by employing distilled water and ethanol as solvents, and glycerol and dibutyl phthalate as plasticizers. These Þ lms were evaluated for weight variation, uniformity of thickness, tensile strength, percentage of elongation at break, folding endurance, hardness, surface pH, and water vapor permeability. Permeability characteristics of these Þ lms were studied using Oß oxacine as a model drug. Film properties of various synthetic polymers such as hydroxypropyl methyl cellulose (HPMC), polyvinyl alcohol (PVA), hydroxypropyl cellulose (HPC), polyvinyl pyrrolidone (PVP), and Eudragit RL 100 were studied for their utility in the formulation of ophthalmic inserts. Sterility test was carried out before performing an irritation study on albino rabbit eyes. There was no sign of any irritation, redness, swelling, or haziness in the rabbit's eyes even after 24 hours after removal of the Þ lm.

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The aim of the present investigation was to prepare and evaluate gastroretentive floating microspheres of Verapamil hydrochloride that would retain the drug in stomach and continuously release the drug in controlled manner up to a predetermined time. Floating microspheres were prepared by emulsion solvent evaporation technique. In the present investigation three polymers were used in various concentrations; Methocel K4M, Methocel K15M and Methocel K100M. In vitro performance was evaluated by the usual pharmacopoeial and other tests such as particle size analysis, drug entrapment efficiency, flow properties, in vitro floatability studies, in vivo floatability studies in dog, in vitro drug release studies, stability studies etc. Results showed that the mixing ratio of components in the organic phase affected the size, size distribution, yield, drug content, floating time and drug release of microspheres. In most cases good in vitro floating behavior was observed and a broad variety of drug release pattern could be achieved by variation of the drug, polymer and solvent ratio.