ABSTRACT:
Compounds with poor aqueous solubility are increasingly posing challenges in the development of new drugs, since a large number of drugs coming directly from synthesis or from throughout screening have a poor solubility. It is well known that drug efficacy can be severely limited by poor aqueous solubility, leading to low dissolution rate and thus results in low absorption in the gastrointestinal tract after oral administration hence compromising oral bioavailability. Among the various strategies for improving aqueous solubility of drug, the solid dispersion approach has been widely and successfully applied to improve the solubility, dissolution rate, and consequently, the bioavailability of poorly water soluble drugs. Although solid dispersions have tremendous potential for improving drug solubility, 40 years of research have resulted in only a few marketed products using this approach. The situation has, however, been changing in recent years because of the availability of surface active and self emulsifying carriers for the preparation of solid dispersions. Some practical limitations of dosage from development might be the inadequate solubility of drugs in carriers and the instability of drugs and carriers at elevated temperatures. This article is devoted to the different carriers used for the production of solid dispersion.