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?

Topical Medication
Regulatory Affairs
Over the Counter (OTC) Drugs
Consumer Testing
Intellectual Property
Rob Walsh
23 months ago

2 answers


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.

Karel Petrak
23 months ago
Maybe; usually just an atomic moiety or two is tweaked for a "new" drug - Dr. David E. 12 months ago

One can use the mechanism for Amending an OTC Drug Monograph by submitting

  1. Citizen petition (
  2. Time and extent application (TEA) (,

Citizen Petition:
Regulated by 21 CFR 10.30 and can be used to amend OTC drug monograph at any stage (Limited to pre - 1975 marketing conditions; “conditions”: active ingredient, dosage form, indication, etc)
Time and extent application (TEA):
Regulated by 21 CFR 330.14 (Effective in 2002) and can be used to amend OTC drug monograph for marketed products that meets “material time material time” and “material extent material extent” requirements of 21 CFR 330.14(b) (

Some important weblinks:


(Hope this information will be useful to you)

Samares B
23 months ago
Thanks - Dr. David E. 12 months ago

Have some input?