To shed light on the regulatory requirements for the development of co-crystals, the FDA is offering drugmakers submitting ANDAs and NDAs a clearer definition of co-crystals that no longer denotes them as an in-process material.

In draft guidance that revises a 2013 final guidance, the FDA eliminates statements that indicate co-crystals meet the regulatory classification of in-process material and should be held to current GMP requirements.

The draft document expands on the scientific and technical classification of co-crystals, emphasizing the ways these components differ from polymorphs and show similarities to solvates.

The previous final guidance led drugmakers to erroneous interpretations that stifled the development of co-crystals, the FDA said. Drugmakers assumed that current GMP requirements would apply to the development of co-crystals because of their classification as in-process material.

“The guidance has not been conducive to the development of co-crystals,” the FDA said.

The recommendations for drugmakers remain unchanged in the draft guidance, as the FDA still asks drugmakers to generate and submit data on the neutral states of the co-crystals.

According to the FDA, the development of co-crystals is beneficial to the drugmakers because these components improve drug bioavailability and the processability of APIs during the manufacturing process.

Comments are due within 60 days of publication in the Federal Register.

FDAnews has brought together all the official references that make up the GMP requirements in one comprehensive resource. Buried in these notices of rulemaking and guidances, you’ll find the full explanations of why the FDA has written the rules the way it has, so keep up with the latest with Guide to FDA Pharma GMP Regulations – 2015.