Impact of seasonal climate variations on pharmaceutical stability in different geographic warehouses: A longitudinal time series statistical analysis

Pharmaceutical stability is critically affected by seasonal environmental variations in temperature and humidity, particularly during warehouse storage in regions experiencing extreme climatic conditions. This longitudinal study assessed seasonal impacts on three temperature-sensitive drugs (Amoxicillin, Metformin, and Omeprazole) over 12 months across pharmaceutical warehouses located in hot-humid, cold-dry, and temperate climatic zones. Environmental parameters were continuously monitored using calibrated data loggers, while drug stability was evaluated quarterly through HPLC analysis of active pharmaceutical ingredient (API) content, degradation product quantification, disintegration testing, and visual inspection. Time series statistical analysis was employed to characterize seasonal degradation patterns and correlations with environmental stressors. Omeprazole and Amoxicillin exhibited pronounced seasonal instability, particularly in hot-humid warehouse conditions during summer months, with Omeprazole experiencing API losses exceeding 20% compared to baseline values. Conversely, Metformin demonstrated remarkable stability across all storage environments and seasons. Time series decomposition revealed significant seasonal components with degradation peaks in the third quarter, accompanied by strong positive correlations between temperature, humidity, and drug deterioration rates. Physical integrity assessments showed capsule discoloration and delayed disintegration in Omeprazole under extreme environmental stress. These findings highlight the critical need for enhanced climate control systems, predictive monitoring technologies, and risk-based storage management strategies to ensure pharmaceutical quality and regulatory compliance across diverse geographical regions.