25-27 April 2023
The United States Food and Drug Administration (FDA) has recently published a Warning Letter sent to Natural Beauty Care Pty Ltd, an Australian manufacturer of over-the-counter (OTC) drug products. The Warning Letter summarizes significant violations of current good manufacturing practice (CGMP) concerning finished drug product testing, identity testing of active pharmaceutical ingredients (APIs), and stability testing.
The Warning Letter also shows the FDA's current backlog in processing inspection findings. The FDA has reviewed the documents the company submitted in response to a request for records and other information sent on April 16, 2020, so more than a year and a quarter ago. The authority placed all drug products manufactured by the firm on Import Alert 66-40 on March 23, 2021. The Warning Letter is dated June 9, 2021, but was not published until August 24, 2021.
Natural Beauty Care Pty Ltd did not conduct adequate finished drug product testing on lots shipped to the United States. The company replied to the FDA's questions about the finished drug product testing procedure that "analytical assay testing for active ingredients is not currently performed for each batch of finished drug products."
The FDA quite rightly points out that "without adequate testing, there is no scientific evidence to support that [...] drug product batches conform to appropriate specifications before release." The company has now been told to conduct "full chemical and microbiological testing of retain samples to determine the quality of all batches of drug product distributed to the United States."
The second point in the Warning Letter relates to identity testing. According to the FDA, the company could not demonstrate that testing to determine the identity of incoming lots of the active pharmaceutical ingredient (API) used to manufacture the OTC drug products were performed. Instead, the company relied solely on vendor certificates of analysis (COA).
In principle, it is acceptable to rely on a vendor COA for quality attributes, but at least one test to verify the identity of each component must be conducted. Furthermore, FDA states that if a company intends "to accept any results from [the] supplier's COA instead of testing each component lot for strength, quality, and purity", it must specify how it "will robustly establish the reliability of [the] supplier's results through initial validation as well as periodic re-validation."
Furthermore, Natural Beauty Care Pty Ltd "faiiled to provide adequate stability data to demonstrate that the chemical properties of [the] drug products remain acceptable throughout the assigned expiry period." The FDA therefore writes to the company that "without appropriate stability data, you cannot ensure your drug products meet established specifications and all pre-determined quality criteria throughout the drug product’s assigned shelf-life."
The firm was requested to submit data to demonstrate the adequacy of its stability program.
In addition to the deficiencies already mentioned, the FDA lists the following aspects:
To view the complete list of violations and the conclusion drawn by the FDA, please see the warning letter to Natural Beauty Care Pty Ltd published on the FDA's website.