Conventional and innovative solubility augmentation techniques: With emphasis on flash nanoprecipitation

The solubility of the API (active pharmaceutical ingredient) in a particular dosage form governs its dissolution behaviour. The main limitation faced by the solid dosage forms are the poor water solubility and lower dissolution rates seen in approximately 40% of the novel APIs. Absorption of drugs which are not soluble in water- like BCS class 2 - into the systemic circulation under normal circumstances may be delayed because of the extended time required for dissolution in gastro intestinal fluid. Several approaches including salt creation, comminution, complex formation, microencapsulating the product and solid dispersion have been implemented on water insoluble drugs to improve their poor dissolution rate. This review enlists the various conventional and innovative techniques for improving solubility and also delves into detail about the novel technique that is flash nano precipitation, its principle, applications, quality by design (QbD) and various equipment used.