Harnessing Microwave Energy for Drug Solubility Enhancement: A Sustainable and Efficient Approach

One of the most tenacious challenges in contemporary drug development is low aqueous solubility, especially of BCS Class II and IV drugs, whose dissolution constraints directly convert to poor oral bioavailability and inadequate clinical response. Other traditional methods (solid dispersions, complexation, and nanosizing) have also been used to enhance numerous candidates, but are commonly based on energy-intensive processing and high consumption of organic solvents, which is contrary to the core tenets of green chemistry and adds complexity and high cost to the manufacturing process. Conventional fusion and solvent-based methods of preparation of solid dispersions or nano formulation lead to degradation of the drugs, take considerable time to process, and find it difficult to scale up, as there is no heat transfer and solvent removal. Although solubility can be increased, not every process is able to control crystalline-amorphous transitions, particle size, and polymorphic form with precise control, resulting in stability problems and lot-to-lot variations. Besides, only a few systematic combinators of process intensification (e.g., microwaves, ultrasonics, supercritical fluids, microfluidics) with AI- and PAT-based monitoring of solubility-enhancing formulations have been rationally designed and optimized through real-time control. The paper will provide a general review of microwave-assisted solubility enhancement, focusing on how mechanisms such as dielectric heating, dipolar polarization, and selective molecular excitation contribute to improving the dissolution rate by amorphizing, reducing particle sizes, and altering crystal structure. It thoroughly describes microwave-assisted solid dispersions, cocrystallization, nanoparticle engineering, and cyclodextrin complexation, and the emerging hybrid platforms that enable a combination of microwaves with supercritical fluids, ultrasonication, and microfluidic systems and gives a overall look at how AI and PAT can be used to control and optimize the operations explaining why technical challenges, regulatory, and overall implications, and how the potential of microwave-based technologies can be ultimately undiscovered as high-speed, scalable and environmentally responsible technologies to improve drug.