<p><?tk 1?>Designing newer drugs requires an alternative approach to solve challenges encountered by the pharmaceutical industry. The main issues associated with formulation of solid drugs are lower solubility, poor bioavailability, and less stability. The most appropriate way to deal with these limitations is to convert liquid formulation using active pharmaceutical ingredient (API). This can be resolved by using API as one of the components to produce deep eutectic solvents (DESs). Due to unique physiochemical properties and designer nature, DESs appeared as better solvent to enhance the solubility, stability, permeability and bioavailability of the resultant drug. This review is intended to discuss the importance of DESs composed of API termed as API-DES, their emergence, design and preparation, types and applications in the pharmaceutical industry. The collective information gathered will provide guidelines for the researcher to choose proper components for designing of new API-based DES with desired physicochemical properties for specific applications, to deal with any difficulties encountered during formulations, to study the targeted applications and to scale up the production of API -DESs at industrial scale. API-DESs represent a significant advancement in resolving the challenges encountered during development of new drug by the pharmaceutical industry. The designer nature and unique physicochemical properties of API-DESs offer great potential to overcome the limitations of several solid drugs and provide cost-effective usage in several applications.</p> Graphical abstract