Topical Formulation of Carbonized Pine Cones: Physical Stability Assessment and Sensory Evaluation

Abstract

Polymeric hydrogel-based creams and oil-based organogels were formulated to develop a topical preparation containing carbonized and triturated powder of pine cone (CPC). Microscopic observation showed homogenous dispersion of CPC throughout the oil phase. Under centrifugal stress (1000-20000xg, 10 min, 20 degrees C), the physical stability of the hydrogel-based formulation was greater than those of organogels. Hydrogel-based ultra-moisturizing cream2 (HUMC2) and lauric acid/Vaseline-based gel2 (LV2) were selected as representative aqueous and organogel formulations, respectively, and both showed shear-thinning behavior in rheograms. A simulated pinch strength test was established to evaluate flow properties of the formulations for practical application. In human sensory evaluation, HUMC2 showed a higher score than LV2 regarding spreadability, moistness, and removal capacity, whereas the shininess score of LV2 was higher than that of HUMC2. In conclusion, HUMC2 was superior to LV2 in most evaluations, but had limited CPC-loading capacity (< 10% w/w), compared to the high loading capacity of LV2 (approximately 40% w/w).