Selection can be based on the facility available for doing research, basic requirement of university and expectation of research guide.

Best way is to find out the information from university website (for Ph.D. scholar's topic) and/or published paper with name of approved guide which can give idea about area of interest of guide.

Thanks

Nano particles as a new approach for enhancing efficacy and improving safety profile of herbal preparations @ Tarun Virmani

Monoclonal antibodies production and in silico efficacy and safety of these compounds.

Liposome techology for enhancement of biomembrane permeability of some phytochemicals or natural extract having great importance as anti inflamatory and anti oxidant properties. example: curcumin, bacoside etc

development, standardization and evaluation of any one ayurvedic medicinal preparation