Preparation and characterization of black seed oil loaded solid lipid nanoparticles for topical formulations: A preliminary study.

Nigella sativa or black cumin is one of the medicinal plants that botanically belongs to the Ranunculaceae family and is literally described as the 'seed of blessings' due to its medicinal use in Islamic historical background. Black cumin has a wide spectrum of pharmacological actions, but its stability is still a limitation. To overcome this, solid lipid nanoparticles (SLNs) was introduced as an alternative carrier system of active compounds. In this study, solid lipid nanoparticles containing black cumin seed oil were successfully prepared by the emulsification-ultrasonication method. The effects of different emulsifiers were studied in terms of particle size. The particle size decreases with increasing lecithin/emulsifier concentration. The dynamic light scattering analysis of solid lipid nanoparticles confirmed the particle diameter of the formulated SLNs stabilized with poloxamer and tween 80 was approximately 220 nm to 1.2 µm. The results obtained from scanning electron microscopy (SEM) revealed the sphere-like shape of SLNs. From the SEM analysis, the diameter of the SLNs was in the range of 250 - 900 nm. Physiochemical characterization using DSC technique demonstrated a difference in crystal structure between SLNs with and without black cumin seed oils. SLNs system has a potential to show a high stable loading capacity of active lipophilic compounds. [ABSTRACT FROM AUTHOR]