Innovations in drug delivery systems.

The history of pharmaceuticals has reflected a concern with the development of new chemical entities. Only recently has the importance of dosage form design been recognized as a vital component of effective therapy. Not only has the time and expense involved in the research of the new molecules escalated dramatically, but it has been discovered that many of these products might be improved through incorporation in rate-controlled dosage forms. Conventional formulations have provided vehicles with which to introduce agents into the body. New therapeutic systems offer great versatility since they permit localized treatment of specific tissues, sophisticated methods of animal experimentation, and controlled-release methods for systemic delivery. These new dosage forms are diverse, precise, and adaptable in many therapeutic situations. A membrane-controlled gastro-intestinal therapeutic (GIT) system resembling a conventional tablet in external appearance has recently been developed. This system is designed for the constant, controlled release over a period of 10 to 12 hours of drug in solution and uses osmotic activity as the source of energy. The GIT system, as used for 'Osmosin' (sodium indomethacin trihydrate), differs from conventional sustained-release and other controlled-release dosage forms in that the rate of release is not dependent upon pH to release the medication and is designed, therefore, to overcome the problems associated with unpredictable release patterns.