SOLUBILITY ENHANCEMENT TECHNIQUES - A REVIEW

Solubility is not to be confused with the ability to dissolve or liquefy a substance, since this process may occur not only because of dissolution but also because of a chemical reaction Solubility is the phenomenon of dissolute on of solid in liquid phase to give a homogenous system. There are many techniques which are used to enhance the aqueous solubility. The ability to increase aqueous solubility can thus be a valuable aid to increasing efficiency and/or reducing side effects for drugs. This is true for parenterally, topically and orally administered solutions. Oral route is the most desirable and preferred method of administering therapeutic agents for their systemic effects, but poorly solubility of drug is major challenge for formulation scientist. About 40% of orally administered drugs suffer from formulation difficulties related to their water insolubility. Dissolution rate, absorption, distribution and excretion of a moiety depend upon its solubility characteristics. On the basis of solubility, drugs are classified into four classes of the BCS classification. We may define a drug as ‘poorly soluble' when its dissolution takes longer than the transit time past its absorptive sites, resulting in incomplete bioavailability. The aqueous solubility of a drug is a prime determinant of its dissolution rate and in the case of poorly soluble drugs Solubility challenges are faced in the Class II and Class IV of the BCS system. The method is suitable for thermo labile materials. Keywords: Solubility Enhancement, bioavailability, poorly water soluble, Dissolution, solid dispersion