A review of multiple techniques utilized for solubility enhancement

Abstract

Pharmaceutical molecules with low water solubility have limited pharmacological potential, which poses a challenge for drug innovation and development. Solubility is a crucial factor for good therapeutic activity and bioavailability of drugs, especially for oral dosage forms, which cover more than 50% of all pharmaceutical dosage forms. Solubility affects pharmacokinetics, pharmacodynamics, drug distribution, protein binding, and absorption. The pharmaceutical industry faces difficulties in formulating and developing around 40% of new chemical entities due to poor solubility and bioavailability. To enhance the bioavailability and solubility of drugs, various technologies are employed, such as complexation, emulsion formation, micelles, microemulsions, cosolvents, polymeric micelle preparation, particle size reduction, pharmaceutical salts, prodrugs, solid-state alternation, soft gel technology, drug nanocrystals, solid dispersion, crystal engineering, micronization, nano sizing, cyclodextrins, solid lipid nanoparticles, and colloidal drug delivery. Class II and IV drugs (APIs) exhibit poor solubility, lower bioavailability, and less dissolution, according to the Classification of Biopharmaceutics. This review highlights advanced methodologies for solubility and bioavailability enhancement.