Technique to Formulation of Amorphous Drug

The development of amorphous drug systems represents a transformative approach to address one of the most persistent challenges in pharmaceutical science—poor aqueous solubility and limited bioavailability of drug candidates. Unlike their crystalline counterparts, amorphous forms possess higher free energy and greater molecular mobility, enabling superior dissolution rates and enhanced absorption. However, their thermodynamic instability introduces formulation and stability challenges that require meticulous design and evaluation. This review systematically explores the theoretical foundation and practical considerations in the formulation of amorphous drugs. Beginning with the fundamental properties of amorphous solids, the discussion progresses to the rationale for amorphization, particularly in the context of Biopharmaceutics Classification System (BCS) class II and IV drugs. Multiple formulation strategies are evaluated, including amorphous solid dispersions, co-amorphous systems, cryogenic milling, and emerging solvent-free technologies. Each approach is discussed in terms of molecular stabilization, scalability, and excipient compatibility. Advanced techniques like XRPD, DSC, TGA, FTIR, NMR, SEM, and AFM are essential in characterizing amorphous drug systems. These methods help confirm the amorphous state, assess stability, and detect drug-excipient interactions. Recrystallization under environmental stress is a major concern, but polymers and co-formers can enhance stability. On the industrial side, quality control and scale-up remain key challenges. Regulatory frameworks such as Quality by Design (QbD) guide systematic development. Looking forward, nanotechnology, AI, and modeling tools are expected to improve the precision and personalization of amorphous drug formulations.