Investigation of β-caryophyllene as terpene penetration enhancer: Role of stratum corneum retention

Molecular Insights into the Penetration Enhancement Mechanism of Terpenes to Skin

Terpenes are widely used in cosmetic formulations as chemical penetration enhancers (CPEs). However, the molecular mechanisms underlying the skin-penetration-enhancing effect have not been completely understood. In this work, molecular dynamics (MD) simulations were used to explore the influence of terpineol (TER), 1,8-cineole (CIN), and limonene (LIM) on the stratum corneum (SC) model. The results indicated that terpenes affected lipid membranes in a concentration-dependent manner and promoted skin permeation by disorganizing the cholesterol (CHOL) portion. The penetration of CPEs across the skin membrane also differed, with diffusion rates of limonene > 1,8-cineole > terpineol. The limonene molecules could penetrate the bilayer's center, forming a "triple layer" membrane structure. Furthermore, constrained simulations showed that the most favorable penetration pathway is via areas rich in CHOL. Terpineol could lower the energy barrier of the hydrophilic molecule (caffeic acid) across the cholesterol region. For the lipophilic molecule (osthole), limonene and 1,8-cineole could reduce the energy barrier across the cholesterol region. Each of the results provides novel insights into the mechanism of penetration of CPEs in the skin.

Enhancing collagen based nanoemulgel for effective topical delivery of Aceclofenac and Citronellol oil: Formulation, optimization, in-vitro evaluation, and in-vivo osteoarthritis study with a focus on HMGB-1/RAGE/NF-κB pathway, Klotho, and miR-499a

The majority of conventional osteoarthritis (OA) treatments are based on molecular adjustment of certain signaling pathways associated with osteoarthritis (OA) pathogenesis, however there is a significant need to search for more effective and safe treatments. This study centers around formulating Aceclofenac (ACF) with high bioavailability in combination with Citronellol oil and collagen. The optimal concentrations of Citronellol oil/D-Limonene oil, Tween 80, and Transcutol HP were determined using a pseudoternary phase diagram. The formulated nanoemulsions were studied for thermophysical stability. Thermodynamically stable formula were analyzed for droplet size, zeta potential, and in-vitro permeation. Then, collagen based nanoemulsion were prepared to capitalize on its efficacy in reducing osteoarthritis side effects and characterized for nano size properties. Formulae F10 and F10C were chosen as optimum nanosize formula. Hense, they were prepared and characterized as nanoemulgel dosage form. The nanoemulgel formulae F10NEG1 and F10CNEG1 showed reasonable viscosity and spreadability, with complete drug release after 4 h. These formulae were chosen for further In vivo anti-OA study. Collagen based ACF/citronellol emugel were able to modulate HMGB-1/RAGE/NF-κB pathway, mitigating the production of inflammatory cytokine TNF-α. They were also able to modulate Klotho and miR-499, reducing serum CTXII and COMP, by reducing the cartilage destruction. Histological investigations validated the efficacy, safety, and superiority of Aceclofenac in combination with Citronellol oil and collagen (F10CNEG1) over solo the treated group (F10NEG1 and blank). Hence, the findings of the current work encourage the use of this promising combined formula in treatment of OA patients.

Terpene-based novel invasomes: pioneering cancer treatment strategies in traditional medicine

Health care workers have faced a significant challenge because of the rise in cancer incidence around the world during the past 10 years. Among various forms of malignancy skin cancer is most common, so there is need for the creation of an efficient and safe skin cancer treatment that may offer targeted and site-specific tumor penetration, and reduce unintended systemic toxicity. Nanocarriers have thus been employed to get around the issues with traditional anti-cancer drug delivery methods. Invasomes are lipid-based nanovesicles having small amounts of terpenes and ethanol or a mixture of terpenes and penetrate the skin more effectively. Compared to other lipid nanocarriers, invasomes penetrate the skin at a substantially faster rate. Invasomes possess a number of advantages, including improved drug effectiveness, higher compliance, patient convenience, advanced design, multifunctionality, enhanced targeting capabilities, non-invasive delivery methods, potential for combination therapies, and ability to overcome biological barriers,. These attributes position invasomes as a promising and innovative platform for the future of cancer treatment. The current review provides insights into invasomes, with a fresh organizational scheme and incorporates the most recent cancer research, including their composition, historical development and methods of preparation, the penetration mechanism involving effect of various formulation variables and analysis of anticancer mechanism and the application of invasomes.

Association effect of the phytocannabinoid beta-caryophyllene and indomethacin carried in topical nanoemulgels: an evaluation by in vivo anti-inflammatory model

The sesquiterpene β-caryophyllene, classified as a phytocannabinoid compound, has been widely studied owing to its multi-target action. In addition, this compound has demonstrated application as a skin permeation promoter. In this context, this study aimed to evaluate the feasibility of associating β-caryophyllene and indomethacin in the oily core of hydrogel thickened nanoemulsions, as well as, to evaluate the in vivo anti-inflammatory effect of this association by croton oil ear edoema induced model. After topical application, the nanoemulgels resulted in increased edoema mass when compared to the substances in their free form. Overall, the results differed from expected, and the data found may be owing to the specificities of the in vivo model applied, as well as the tested ratio between β-caryophyllene and indomethacin (200:1). New perspectives arise from the data found regarding the evaluation of the association of terpenic compounds with indomethacin in nanoemulsified systems.

Characterization of a human lesioned-skin model to assess the influence of skin integrity on drug permeability

The stratum corneum (SC) is the skin's outermost layer, organized by clusters of corneocytes among a lipid matrix, acting as a barrier. This "brick and mortar" organization is modified in many skin diseases. We proposed a lesioned-skin model for assessing the permeability of topical formulations and the impact of skin integrity on the permeability of molecules. We anticipate that removal of the SC compromises the skin barrier function, making it more permeable, affecting the biopharmaceutics of topical formulations. By stripping with 25 strips (Corneofix®), the thickness of the SC was considerably reduced, exposing the viable epidermis. Transversal and upper views of the skin by electronic microscopy and histology confirm the removal of the SC. After, we evaluated the permeability of tacrolimus (Protopic®, 0.1 % and 0.03 %) by HPLC-UV. The non-lesioned skin presented 20-25 % of tacrolimus in the SC and no drug permeated through the skin's inner layers. Contrary, the lesioned-skin model allowed the permeation of tacrolimus to the epidermis, dermis, and also in the receptor medium. These results highlight the importance of using diseased skin tissue as opposed to normal skin when assessing the permeability of pharmaceutical formulations for local topical delivery, closely mimicking the occurred events in clinical scenario.