Content Analysis of US FDA Warning Letters Issued to Compounding Pharmacies Regarding Violations of Current Good Manufacturing Practices Between 2017 and 2022

PURPOSE: Assessment of the US FDA-issued WLs content is an educational tool that can be used in the continuous training program of community pharmacists in compounding pharmacies. The study was designed to critically assess FDA warning letters (WLs) issued to compounding pharmacies in 2017–2022 for violations of Current Good Manufacturing Practices (cGMP). METHODS: Content analysis was used to evaluate WLs issued concerning (1) type of violations; (2) frequency of violations mentioned in the WLs; (3) specific evaluations of the deviations related to compounded sterile products, and (4) evaluation of corrective measures requested by the US FDA. RESULTS: A total of 141 WLs were evaluated. The main observed violations in the analyzed WLs were adulterated drug products (130), misbranded drugs (103), unapproved new drug products (42), failure to report adverse events (22), and failure to report drugs (11). Other violations were evaluated related to sterile product compounding with emphasis on personnel qualifications, quality control procedures, equipment, etc. CONCLUSION: The continuous issuance of WLs by the FDA indicates the need for compounding pharmacies become more vigilant to reduce the recurrence of the addressed violations through establishing adequate training/retraining programs. The analysis of issued WLs can serve as a learning tool to help improve compounding procedures, reduce the recurrence of these violations, and enhance patient safeguards. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12247-022-09692-4.