Quality assessment, stability and in-vitro anti-inflammatory activities of a topical ointment containing cannabis and turmeric extracts for haemorrhoids and skin diseases

• The topical ointment formulation containing cannabis and turmeric extracts successfully modified for haemorrhoids and skin diseases. • HPLC methods for cannabinoids and curcuminoids are accurate and precise in the ointment. • Developed formula stable at 50 °C for 1 month, with a shelf life of 9 months. • Turmeric rhizome extract (TM), cannabis leaf extract (CL), and the mixture of all ingredients (MI) displayed high inhibitory effects on TNF-α, while CL and MI suppressed IL-1β. • All ingredients inhibited nitric oxide production, with TM exhibiting the strongest activity. Cannabis sativa L. has long been used in Thai traditional medicine which has included a preparation containing powders of cannabis leaves and turmeric rhizomes, in cottonseed oil, that have been effectively used as a topical paste for haemorrhoids and skin diseases. This traditional formulation was successfully modified and developed as an ointment preparation for assisting patient compliance. In this study, our purpose was to 1) establish the quality control method, 2) study the stability of the formulation and 3) evaluate the anti-inflammatory activity of the formulated ointment and its ingredients. The ingredients in the ointment include cannabis leaf extract (CL), turmeric rhizome extract (TM) and cottonseed oil (CO). HPLC methods for the determination of cannabinoids and curcuminoids in the extracts and the ointment were validated. The ointment was subjected to stability evaluation. Each ingredient and the mixture of all ingredients (MI) were evaluated for their effects on LPS-induced pro-inflammatory cytokines in THP-1 monocytes and nitric oxide in RAW 264.7 macrophage cells. The HPLC methods were accurate and precise. The ointment contained curcumin (2.10 %), bisdemethoxycurcumin (1.82 %), demethoxycurcumin (0.95 %) and delta9-tetrahydrocannabinol (0.08 %). The accelerated stability test at 50 °C for 1 month showed that the developed formula remained stable, with a shelf life of 9 months. The TM, CL and MI (10 µg/mL) expressed a high inhibitory effect on TNF-α whereas CL and MI strongly suppressed IL-1β. All samples (25 µg/mL) significantly inhibited nitric oxide production of which TM exhibited the strongest activity. The novel formulated ointment, derived from traditional practice for treating haemorrhoids and skin diseases, demonstrated satisfactory quality, stability, and in-vitro anti-inflammatory activity.