The US Food and Drug Administration (FDA) has released a new draft guidance document pertaining to stability testing of generic drug products and substances which calls for sponsors to rely on five existing standards promoted by the International Conference on Harmonisation (ICH).

Abbreviated New Drug Applications (ANDAs) are commonly used to support generic drug applications under section 505(j) of the Federal Food, Drug and Cosmetic Act (FD&C Act).

FDA said it has been receiving increasing numbers of inquiries regarding ANDA stability requirements, and no longer felt a 1995 guidance letter establishing room temperature conditions for stability studies was, "Sufficient to serve as a basis for stability testing for ANDAs."

FDA said that under the new draft guidance, Guidance for Industry - ANDAs: Stability Testing of Drug Substances and Products, ANDA sponsors should conform to five stability recommendations put forth by ICH:

• Q1A (R2) Stability Testing of New Drug Substances and Products
• Q1B Photo Stability Testing of New Drug Substances and Products
• Q1C Stability Testing for New Dosage Forms
• Q1D Bracketing and Matrixing Designs for Stability Testing of New Drug Substances and Products
• Q1E Evaluation of Stability Data

"Although the ICH stability guidances were developed by ICH to provide guidance on the information that should be provided in new drug applications to ensure the stability of new drug substances and drug products, we believe the recommendations should be applied to ANDAs as well," FDA explained.

Sponsors should be prepared to submit data from three pilot-scale batches or two pilot-scale batches and one small-scale batch, said FDA. In addition, sponsors should provide six months of accelerated and long-term condition data, with the drug being manufactured and stored in conditions representative of the final process.

FDA said sponsors should also:

• "Use multiple lots of drug substance as appropriate."
• "Provide a fully packaged primary exhibit batch."
• "Use three batches when using bracketing and matrixing designs under ICH Q1D."
• "Provide statistical analysis of the data as appropriate, in accordance with ICH Q1E, Appendix A."

Justifications should be provided for any deviations from the guidance's suggestions, noted FDA.