What kind of Isolator we should use for potent yet DPI & what should be the pressure in side positive or negative

A sterile DPI (Dry Powder Injection) line having potent product handling and the product is being handled in a closed Isolater system.

I have this doubt regarding the design of Isolator, whether we should go with negative pressure isolator to safeguard operator or should we go with positive pressure isolator to maintain product sterility in case of any breach but at the same time put operator in a high exposure risk.

So, How we can proceed ahead with this partiular scenario and what risk assessment and measures should be taken care so that both operator as well as product safety can be maintained?