A critical review on developments in drying technologies for enhanced stability and bioavailability of pharmaceuticals

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.

Graphical Abstract

Keywords:

• Freeze drying
• spray drying
• nano-spray drying
• dissolution
• bioavailability

Acknowledgement

One of the authors is grateful to Institute of Nano Science and Technology (INST), India for providing research fellowship.

One of the authors is grateful to Dr. Babasaheb Ambedkar Research and Training Institute (BARTI), Pune for providing research fellowship.

Disclosure statement

The authors report no conflicts of interest.

Additional information

Funding

UGC-BSR Mid-Career Award Grant (F. 19-251/2020 (BSR)), University Grants Commission (UGC), New Delhi.