Gowning procedure in API

What is the gowning procedure for class 8 or Grade D in API clean rooms India and international sites.

I don’t know for India, specificly; but generally, there is no difference between same grade (e.g. grade D) for API, medical device or medicinal products; the same requirements as for grade D for medicinal products can be expected internationally, to reduce the risk of contamination of the API.

However, additional controls might be needed depending on specific risks identified through risk management activities, and sometimes specific regulatory requirements may indicate additional controls.

Taken from PIC/S: PIC/S ANNEX 1 GUIDE TO GOOD MANUFACTURING PRACTICE FOR MEDICINAL PRODUCTS

Grade D: Hair, beards and moustaches should be covered. A general protective suit and appropriately disinfected shoes or overshoes should be worn. Appropriate measures should be taken to avoid any ingress of contaminants from outside the clean area.
Additional gowning including gloves and facemask may be required in grade C and D areas when performing activities considered to be a contamination risk