A critical review on developments in drying technologies for enhanced stability and bioavailability of pharmaceuticals
Krishna Jadhav, Eknath Kole, Raghuraj Singh, Saroja Kumar Rout, Rahul Kumar Verma, Aniruddha Chatterjee, Arun S. Mujumdar, Jitendra Naik
Abstract
Drying is a widely adopted unit operation that enhances the stability of pharmaceuticals. Conventionally, freeze-drying has been chosen, as evidenced by the numerous freeze-dried products available on the market. However, there are drawbacks related to freeze drying, extended drying times, freezing and processing-related stresses, and it operates as a batch process, making integration into continuous manufacturing schemes challenging. Similarly, spray drying has garnered significant consideration in the chemical and pharmaceutical industries, but limited production yields hinder its adoption. These shortcomings prompted a quest for next-generation drying technologies tailored for therapeutic products. The emerging drying technologies include nano-spray drying, spray freeze drying, thin film freeze drying, supercritical fluid drying, foam drying, and other miscellaneous techniques to cater to stability issues and enhanced bioavailability. While certain drying technologies have been successfully implemented in the processing of therapeutics, others are currently undergoing early-stage feasibility assessments. This review aims to comprehensively understand novel drying technologies and their potential to tailor pharmaceuticals and biologicals for optimal therapeutic outcomes.