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Mucoadhesive patch releasing the drug in the oral cavity at predetermined rate may present distinct advantages over traditional dosage forms such as tablets, gels and solutions. The present study was concerned with the preparation and evaluation of mucoadhesive buccal patches for the controlled systemic delivery of Salbutamol sulphate to avoid first pass hepatic metabolism. The developed patches were evaluated for the physicochemical, mechanical and drug release characteristics. The patches showed desired mechanical and physicochemical properties to withstand environment of oral cavity. The in-vitro release study showed that patches could deliver drug to the oral mucosa for a period of 7 h. the patches exhibited adequate stability when tested under accelerated conditions.

The purpose of the present study was to investigate incorporation of hydrophobic (ie, waxy) material into pellets using a thermal sintering technique and to evaluate the pellets in vitro for controlled release. Pellets prepared by extrusionspheronization technology were formulated with a watersoluble drug, microcrystalline cellulose, and carnauba wax. Powdered carnauba wax (4%-20%) prepared by grinding or by emulsification was studied with an attempt to retard the drug release. The inclusion of ground or emulsified carnauba wax did not sustain the release of theophylline for more than 3 hours. Matrix pellets of theophylline prepared with various concentrations of carnauba wax were sintered thermally at various times and temperatures. In vitro drug release profiles indicated an increase in drug release retardation with increasing carnauba wax concentration. Pellets prepared with ground wax showed a higher standard deviation than did those prepared with emulsified wax. There was incomplete release at the end of 12 hours for pellets prepared with 20% ground or emulsified wax. The sintering temperature and duration were optimized to allow for a sustained release lasting at least 12 hours. The optimized temperature and duration were found to be 100°C and 140 seconds, respectively. The sintered pellets had a higher hydrophobicity than did the unsintered pellets. Scanning electron micrographs indicated that the carnauba wax moved internally, thereby increasing the surface area of wax within the pellets.

Nonoxynol-9 (N-9) is a typical surfactant. For more than 30 years that very property of N-9 has been successfully exploited for its spermicidal action. It is available as an over-the-counter, locally acting vaginal spermicide. The suitability of N-9 as a spermicide is elaborated in this article. The reasons why N-9 may fail as a contraceptive are discussed. In spite of many drawbacks, which are mentioned in the article, N-9 is still often resorted to as a locally acting contraceptive. The review ends with suggestions to alter the molecular structure of N-9 and to adjust the dosages.