What are some of the regulatory, technical, and clinical hurdles that could potentially impact efforts to reformulate an OTC drug in a new topical application? How might such hurdles be avoided or mitigated to achieve efficient consumer testing?
At minimum, one needs to demonstrate “bioequivalence” of the new formulation in terms of pharmacokinetics (ADME - administration, distribution, metabolism, elimination), and also its safety.
Further, the new formulation should offer an advantage to patients; why else should a regulatory agency approve a new formulation?
If the formulation is novel, it could be patented; if we talk about a generic drug, its patent would have expired so the drug could be a part of this invention, perhaps.