Production of pharmaceutical micro and nano particles by subcritical water based technologies: A review

Abstract

Low bioavailability of the drug caused by two factors of low aqueous solubility and low rate of drug dissolution is one of the most important challenges in the pharmaceutical industry. The reduction of particle size to micro or nano scale is one of the methods utilized in recent years to increase the solubility and dissolution rate of drugs with low aqueous solubility. In recent years, much attention has been paid to subcritical water as a green and bio-friendly solvent. The process of subcritical water has eliminated many of the disadvantages of conventional methods for reducing particle size. Thus, the present study performed a comprehensive review of the studies and the latest advances in the production of pharmaceutical micro and nano particles with low solubility in water using subcritical water based technologies. Subcritical water based technologies were divided into three main categories: a combination of subcritical water technology with a supercritical fluid process, a spray drying process, and anti-solvent precipitation. Nano-drugs that have been produced by these methods so far have been listed. The influence of operating parameters on the properties of the produced particles has been examined. Special emphasis has been put on the method of production of pharmaceutical micro and nano particles using the method of combining subcritical water technology with the anti-solvent precipitation method. Finally, the prospects of existing challenges and opportunities for scale-up and commercialization of particle production technology using subcritical water are discussed.