A Comprehensive Review on Solubility Enhancement Techniques for Poorly Water-Soluble Drugs

Solubility refers to the ability of a solid to dissolve in a liquid and form a consistent solution. Ensuring that there is the proper dosage of medicine in the blood is vital for its effectiveness or desired pharmacological response. A significant challenge in developing new medications is that many of them have poor solubility in water. This is particularly applicable to in BCS Class II and IV. The slow dissolution of these drugs leads to inadequate absorption in the body when they are taken orally. In this review, the necessity of improving solubility is highlighted, along with an explanation of how the solubilization process operates and the main physical and chemical elements that impact it. This review primarily aims to explore methods that enhance the absorption and bioavailability of drugs that are poorly soluble in the body. Various conventional and advanced solubility methods for enhancing solubility are meticulously examined. This includes particle size reduction, pH modification, cosolvency, hydrotropy, solid dispersion, complexation, surfactant-based systems, and nanotechnology-driven approaches. The objective of this review is to discuss a range of approaches to boost the dissolution of substances, ultimately aiming to enhance the performance of drugs.