Enhanced effectiveness of tocotrienol-based nano-emulsified system for topical delivery against skin carcinomas.

The potent anti-proliferative and pro-apoptotic actions of tocotrienols (T3) against cancer, but not normal tissues, have been hampered by their limited systemic bioavailabilty. Recent expansive development of diverse nanoemulsion (NE) vehicles emphasized their vast potential to improve the effective dosing of different clinical and experimental drugs of lipophilic nature, such as T3. The emphasis of the present work is to develop a pharmaceutically scalable, low-energy nano-emulsification approach for optimized incorporation of T3-rich palm oil (Tocomin®), possessing anticancer activity as a potential cutaneous delivery platform for adjunctive therapy of skin carcinomas, either alone or in combination with other chemotherapeutic agents. Different Tocomin®-NEs, obtained with different homogenization strategies, were screened based on physicochemical uniformity (droplet size, charge and polydispersity) and subjected to stress physical stability testing, along with chemical content analysis (≥90% Tocomin® - incorporation efficiency). Adopted hybrid nano-emulsification of Tocomin®, correlated with highest preservation of DPPH-radical scavenging capacity of active T3 in prototype formulation, Tocomin®-NE, which effectively permeated diffusion cell membranes 4-folds higher than propyleneglycol (PG)-admixed Tocomin® control. Against two different cell models of human cutaneous carcinoma, Tocomin®-hybrid NE demonstrated significantly stronger cytotoxic profiles (p ≤ 0.01), visible in both concentration- and time- dependent manners, with at least 5-folds lower IC50 values, compared to those estimated for the closest Tocomin®-control. The proposed hybrid nano-emulsified formulation of Tocomin® provides simple and stable delivery platform, for effective topical application against keratinocyte tumors.

Development and In Vitro Evaluation of Vitamin E-Enriched Nanoemulsion Vehicles Loaded with Genistein for Chemoprevention Against UVB-Induced Skin Damage.

There is a great need for effective protection against cutaneous pathologies arising from chronic exposure to harmful solar UVB radiations. A promising pharmaceutical strategy to improve the efficacy of chemotherapeutic/preventative natural compounds (e.g., soy isoflavone Genistein, Gen) is to enhance their dermal delivery using nanoemulsion (NE) formulations. This report investigates the development of nanoemulsified tocotrienol(T3)-rich fraction of red palm oil (Tocomin®), to yield an optimal NE delivery system for dermal photoprotection (z-average size <150 nm, ζ-potential ≈ -30 mV, polydispersity index < 0.25). Physicochemical characterization and photostability studies indicate NE formulations utilizing surfactant mixture (Smix) of Solutol® HS-15 (SHS15) blended with vitamin E TPGS (TPGS) as cosurfactant was significantly superior to formulations that utilized Lutrol® F68 (LF68) as the cosurfactant. A ratio of 60:40 of SHS15-TPGS-NE was further identified as lead Tocomin® NE topical platform using in vitro pharmaceutical skin reactivity studies that assess cutaneous irritancy and cytotoxicity. Prototype Tocomin® NE loaded with the antiphotocarcinogenic molecule Gen (Gen-Tocomin® NE) showed slow-release profile in both liquid and cream forms. Gen-Tocomin® NE also showed excellent biocompatibility, and provided substantial UVB protection to cultured subcutaneous L929 fibroblasts, indicating the great potential of our Tocomin® NE warranting further prototype development as topical pharmaceutical platform for skin photoprotection applications.

Development and evaluation of tocopherol-rich argan oil-based nanoemulsions as vehicles possessing anticancer activity.

In recent years, diverse nanoemulsion vehicles (NEs) have been developed with vast potential for improving therapeutic index of clinically approved and experimental drugs. Using oils rich in omega-3 and omega-6 polyunsaturated fatty acids (PUFA), several promising nanoemulsion formulations have been developed recently for oral and systemic administration. The aim of our present work is to successfully develop and characterize optimized nanoemulsion platform, using the PUFA-rich argan oil that contain several important anti-inflammatory and antimitotic natural components. Using various emulsifying mixtures of polyethoxylated solutol HS-15 and polyethyleneglucol Vitamin E succinyl ester (TPGS), to form different NEs showing extended shelf-life stability. The physicochemical properties of prototype argan NEs were analyzed and utilizing a 32 full factorial design, followed by biocompatibility screen, using normal vascular myocytes and areolar fibroblasts. While 90-180 day stability of NEs correlated with TPGS:solutol surfactant blend ratios, adverse effects on integrity of test cultures were only noted at high TPGS content in the emulsifier system, exceeding 80%. Finally, the anti-proliferative efficacy of selected stable and acceptably biocompatible nanoscale TPGS-emulsified argan oil formulations was investigated using murine breast and colon carcinoma cells. The IC50 values of the combination of argan oil and TPGS (40-80% wt of emulsifiers) were 5-9 folds lower compared to TPGS-free and argan-oil free control NEs. Argan oil NE, stabilized with Vitamin E TPGS and solutol HS mixtures, demonstrated significant pro-apoptotic effect on both test cancer cell lines, indicating built-in anticancer properties for such NE platform, potentially enhancing overall antineoplastic effects of incorporated candidate chemotherapeutic agents.