Solubility and Dissolution Enhancement: An overview

Poorly water soluble compounds have solubility and dissolution related bioavailability problems. The dissolution rate is directly proportional to solubility of drugs. Drugs with low aqueous solubility have low dissolution rates and hence suffer from oral bioavailability problems. The poor solubility and poor dissolution rate of poorly water soluble drugs in the aqueous gastro intestinal fluids often cause insufficient bioavailability. Other in-vivo consequences due to poor aqueous solubility include increased chances of food effect, more frequent incomplete drug release from the dosage form and higher inter-patient variability.Enhancement of solubility, dissolution rate and bioavailability of drug is a very challenging task in drug development, nearly 40% of the new chemical entities currently being discovered are poorly water soluble drugs. Aqueous solubility of any therapeutically active substance is a key property. As it governs dissolution, absorption and thus the in vivo efficacy. The present review deals in detail about the different techniques used for the improvement of the solubility and dissolution rate of poorly water soluble drugs include, Inclusion complexation with cyclodextrins, Size reduction technology, Functional polymer technology and Solid dispersions etc.