Passive Enhancement of Retinol Skin Penetration by Jojoba Oil Measured Using the Skin Parallel Artificial Membrane Permeation Assay (Skin-PAMPA): A Pilot Study

Abstract

Introduction Retinol is known to have positive benefits on the skin including enhancements in barrier function, increased epidermal thickness, reductions in fine lines and wrinkles and reductions in hyperpigmentation. Improved methods to enhance the penetration of retinol are desirable. Methods A study was conducted to examine if addition of natural jojoba ( Simmondsia chinensis ) oil might help passively enhance the penetration of retinol through the skin’s lipid barrier. The model used to examine the passive penetration of the retinol is the skin parallel artificial membrane permeation assay (Skin-PAMPA). In this study, three formulations were examined. The formulations included two control blends: a moisturizing emulsion without retinol and the same product containing 1.0% retinol without jojoba oil. The remaining formulation contained similar concentrations of retinol with 10% jojoba oil. The studies were conducted by applying the products to the Skin-PAMPA models at 37°C/5% CO 2 for 16 hours and then extraction of the acceptor reservoir with cyclohexane (ratio 1:5 acceptor fluid to cyclohexane). The resulting acceptor reservoir cyclohexane solutions were analyzed for retinol by High Performance Liquid Chromatography (HPLC). Results The formulations without retinol showed no indications of retinol penetration by HPLC. The control formulation with 1.0% retinol demonstrated that retinol had permeated the membrane in the 16-hour timeframe with a measured Area Under the Curve (AUC) of 7 units. Analysis of the formulation containing 1.0% retinol and 10% jojoba oil indicated retinol had permeated with a AUC of 285 units, a nearly 40-fold increase in active retinol permeation. Discussion The ability for jojoba oil to directly act to help skin permeation of a key skin care active like retinol has not been previously demonstrated. This potential for jojoba oil to enhance passive skin penetration of critical skin actives, like retinol, can help to improve the performance of skin care products employing active topical ingredients.

New Skin‐Relevant Cell Coculture Model With Stratum Corneum–Like Layer

“…Here, we utilized such a coculture system to which we added a hydrophobic PVDF membrane coated with a phospholipid. Such membranes have been extensively used to investigate the passive diffusion of skin actives, including the cosmetic ones, in PAMPAs [ 7 , 17 , 18 ]. However, to the best of our knowledge, this is the first time that the PAMPA was combined with life cell culture and used as an artificial stratum corneum –like barrier for bioactivity/cytotoxicity cell-based assays.…”

Cosmetic Formulations from Natural Sources: Safety Considerations and Legislative Frameworks in the European Union

“…For instance, natural antioxidant molecules have been shown to exhibit low dermal absorption properties and strategies to improve their cutaneous permeation, such as nano-encapsulation have been discussed [96,97]. In addition, the use of excipients such as jojoba oil was demonstrated in an in vitro study to potentiate the dermal absorption of retinol [98].…”

Recreating Human Skin In Vitro: Should the Microbiota Be Taken into Account?

“…For example, this model has been exploited by Rahma and colleagues [16] for the assessment of the permeation of phenoxyethanol, a common preservative ingredient in baby wipe formulations; notably, the authors observed a positive correlation for the total amount of permeated phenoxyethanol between this artificial membrane and porcine or human skin placed in a Franz diffusion cell, a widely used system to test drug permeation in vitro [16][17][18]. A skin PAMPA was also used to assess the penetration of retinol with the addition of natural jojoba oil as a penetration enhancer: interesting data were obtained on the transdermal delivery capability of jojoba oil since the retinol permeation registered was nearly 40-fold greater when associated with the oil, probably due to its ability to increase the fluidity of the lipid barrier [19]. However, skin PAMPAs have some drawbacks.…”