FDA offers guidance for generic drug developers of hydroxychloroquine, chloroquine

The FDA on Monday issued two new product-specific guidance documents for the unproven but highly demanded potential Covid-19 drugs chloroquine phosphate and hydroxychloroquine sulfate.

The two generic drugs, approved by FDA as malaria drugs, have been touted by President Donald Trump in press conferences during the pandemic, but clinical trial data regarding their efficacy for COVID-19 remain thin.

Regardless, 30 million doses of hydroxychloroquine sulfate was donated to the federal government by Sandoz, the Novartis generics and biosimilars division, and one million doses of Resochin (medical grade chloroquine phosphate) was donated by Bayer Pharmaceuticals. Sanofi also said it?s donating doses of hydroxychloroquine across 50 countries, while generic drugmakers Teva, Sun Pharmaceutical and Amneal also pledged millions of doses.

FDA on 30 March issued an Emergency Use Authorization and allowed the US Biomedical Advanced Research and Development Authority to begin distributing the donated doses to states.


The hydroxychloroquine sulfate guidance finalizes the April 2011 draft of the same title and adds advice about a Biopharmaceutics Classification System-based biowaiver option.

?A waiver request of in vivo testing for this product may be considered provided that the appropriate documentation regarding high solubility, very rapid dissolution, and the test product formulation is qualitatively the same and quantitatively very similar as detailed in the Guidance for Industry: Waiver of In Vivo Bioavailability and Bioequivalence for Immediate Release Solid Oral Dosage Forms Based on the Biopharmaceutics Classification System is submitted in the application. A decision regarding the acceptability of the waiver request will be made upon assessing the data submitted in the application,? the guidance says.

The product-specific guidance for chloroquine phosphate clarifies that the product is AA rated in the Orange Book, meaning that there are no known or suspected bioequivalence problems, and no in vivo studies are necessary, FDA said.

Due to the Covid-19 public health emergency, FDA noted that the chloroquine phosphate guidance is being issued as a final guidance and not as a draft guidance as is usual.

Product-Specific Guidances for Chloroquine Phosphate and Hydroxychloroquine Sulfate

RAPS: First published in Regulatory Focus? by the Regulatory Affairs Professionals Society, the largest global organization of and for those involved with the regulation of healthcare products. Click here for more information.