STABILITY STUDIES OF FINISHED PRODUCT OF DRY MEDICAL CANNABIS FLOWER: ANALYSIS OF QUALITY AND CANNABINOID CONTENT

Abstract

With the increased therapeutic use of medical cannabis, ensuring quality, safety, and efficacy throughout shelf life is essential. This study evaluates stability of dry medical cannabis flower under different storage conditions, focusing on physicochemical quality and cannabinoid content changes over time. Three production batches (P050022, P050072, P050202) of THC-dominant dry cannabis flower (Chemotype I, Total THC >20%) produced at Purely Plant GmbH, were subjected to long-term stability studies (LTSS: 25°C ± 2°C, 60% ± 5% RH) and accelerated stability studies (ACCSS: 40°C ± 2°C, 75% ± 5% RH) over a 3-month period in accordance with ICH Q1A(R2) guidelines. Cannabinoid content was analyzed using validated HPLC-UV method based on German Pharmacopoeia (DAB) Cannabis flos monograph. Initial Total THC content was 23.84 ± 1.40% (n=3 batches). Under LTSS conditions, Total THC showed degradation of 7.27-9.40% after 3 months, while THCA decarboxylation reached 25-29%, with calculated half-lives of 21-28 months. Under ACCSS conditions, THCA decarboxylation was nearly complete (>97%) after 1 month, with Total THC degradation of 6.94-16.23%. Kinetic analysis revealed rate constants k = 0.025-0.033 month⁻¹ for LTSS and Q10 factor of 1.37. CBN formation as oxidative degradation marker remained below specification (<1.0%) under all conditions, confirming effectiveness of nitrogen atmosphere packaging (PET/ALU/PE). Microbiological purity and heavy metal content remained within pharmacopeial limits. This study demonstrates acceptable stability under recommended storage conditions (≤25°C, RH 55-65%, protected from light, inert atmosphere), supporting minimum 12-month shelf life with potential extension to 24 months pending continued studies