SUPPLEMENTAL NDA CLEARANCE FOR STABILITY TESTING IS NOT REQUIRED

SUPPLEMENTAL NDA CLEARANCE FOR STABILITY TESTING IS NOT REQUIRED for repacking procedures when a new container closure system can be shown to be as protective as the original system, FDA's Drug Quality Compliance Div. said in a recently-released inspection guide. The new guide points out to inspectors that current agency policy allows for drug products to be repeaked into container-closure systems "that can be demonstrated to be at least as protective or more protective than the original system without performing new stability studies prior to marketing." The guide reminds inspectors, however, that repackers are subject to applicable Current Good Manufacturing Practices (CGMPs), and that those repackers who rely on stability studies performed by the manufacturer must have copies of all analytical data necessary to support the expiration dating period. Copies of the inspection technical guide on drug product expiration dating and stability testing were released to FDA field offices during the first week of November. The inspection guide was written by FDA's Office of Compliance to flesh out the broadly written GMP requirements as stated in the Code of Federal Regulations (CFR) and to update FDA investigators on current agency compliance policy regarding GMPs. FDA released a stability draft guideline in May 1984 to inform firms specifically about stability information that should be included in NDA submissions. The instructions to field investigators, by contrast, are intended to inform FDA inspectors about current GMP interpretations by the agency regarding stability testing and expiration dating for all finished pharmaceuticals. In addition, the inspection guide advises FDA inspectors when to recommend action for GMP non-compliance. Other requirements addressed by the inspection guide involve the number of batches FDA wants to see tested (minimum of three initial batches), test intervals (at least every year), storage conditions (use of 24-25 degrees C as a room temperature reference), test methods (inclusion of a stability indicating test to distinguish active ingredients from degradation products), container sizes (smallest container sizes must be tested), and preservatives (monitor at same testing times as other ingredients). The guide informs inspectors that mfrs. of bulk drug substances should also be expexted "to assure that their product is stable for the intended period of use," and outlines the features that a bulk drug stability testing program should contain. Samples from at least one commercial-size batch should be included, the Compliance Office states, and thereafter, one batch each year should be entered into the program. The guide emphasizes the importance of testing the container-closure system for drug products purporting to be sterile. However, having demonstrated that any particular container-closure system maintains sterility throughout the expiration dating period, the guide states, it is unnecessary to revalidate for other ingredients.