Preparation, Characterization and Permeation Study of Topical Gel Loaded with Transfersomes Containing Asiatic Acid

Newly Developed Semi-Solid Formulations Containing Mellilotus officinalis Extract: Characterization, Assessment of Stability, Safety, and Anti-Inflammatory Activity

Melilotus officinalis has been traditionally used as an anti-inflammatory agent; nevertheless, a comprehensive evaluation of its efficacy and safety and comparison with standard drugs are lacking. Taking into consideration concerns with current therapies, like efficacy limitations, side effects, and resistance, we aimed to develop a natural gel and cream based on Melilotus officinalis extract and explore their anti-inflammatory potential. After the chemical analysis of the extract confirmed the presence of coumarin, p-coumaric acid, gallic acid, and quercetin, formulations were prepared and subjected to physical and chemical stability evaluations over 6 months. The safety potential was tested in rats, while the anti-inflammatory activity was assessed both via in silico tests and in a rat model of inflammation. The examined formulations showed stable physical characteristics at the defined storage conditions and did not exert any sign of adverse skin reaction. The gel formulation exhibited a remarkable effect in inflammation reduction comparable with hydrocortisone. The in silico results suggest that coumarin, p-coumaric, and gallic acid bind to COX-1 and COX-2 with a lower affinity compared to diclofenac. On the other hand, quercetin demonstrated comparable inhibitory activity and stronger interaction compared to the control drug. Our results indicate that the examined formulations are stable and safe and may be promising dermal products for the alleviation of inflammatory skin conditions.

Enhancement of skin localization of β-carotene from red fruit (Pandanus conoideus Lam.) using solid dispersion-thermoresponsive gel delivered via polymeric solid microneedles

Red fruit (Pandanus conoideus Lam.) boasts high β-carotene (BC) content, often consumed orally. However, absorption issues and low bioavailability due to food matrix interaction have led to transdermal delivery exploration. Nevertheless, BC has a short skin retention time. To address these limitations, this study formulates a β-carotene solid dispersion (SD-BC) loaded thermoresponsive gel combined with polymeric solid microneedles (PSM) to enhance in vivo skin bioavailability. Characterization of SD-BC includes saturation solubility, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and in vitro release. Characterization of SD-BC thermoresponsive gel includes gelation temperature, viscosity, rheological behaviour, pH, bio-adhesiveness, spreadability, and extrudability. PSM's mechanical properties and insertion capability were assessed. Ex vivo and in vivo dermato-pharmacokinetic studies, drug content, hemolysis, and skin irritation assessments were conducted to evaluate overall performance. Results confirm amorphous SD-BC formation, enhancing solubility. Both SD-BC thermoresponsive gel and PSM exhibit favourable characteristics, including rheological properties and mechanical strength. In vitro release studies showed a seven-fold increase in BC release compared to plain hydrogel. SD-BC thermoresponsive gel combined with PSM achieves superior ex vivo permeation (Cmax = 305.43 ± 32.07 µg.mL-1) and enhances in vivo dermato-pharmacokinetic parameters by 200-400 %. Drug content, hemolysis, and skin irritation studies confirmed its safety and non-toxicity.

Harnessing the potential of fatty Acid-Surfactant-Based micellar gel for enhanced topical delivery of Apremilast in psoriasis treatment

Apremilast (APR) is a potent anti-psoriatic agent that inhibits the phosphodiesterase 4 enzyme. Due to the poor oral bioavailability and associated systemic side effects the clinical applicability of APR has been constrained. Nanotechnology-based carrier system presents a novel option to increase the efficacy of the topical treatment of APR. The current investigation deals with the development of fatty acid-surfactant conjugate-based hybrid mixed micellar gel (HMMG) for the topical delivery of APR. The developed micelles exhibited an average size of 83.59 ± 4.46 nm, PDI of 0.239 ± 0.047, % entrapment efficiency of ∼ 94.78 ± 3.98 %, with % practical drug loading of ∼11.37 ± 3.14 %. TEM analysis revealed the spherical shape of micelles. The hybrid micelles were further loaded in a carbopol®934P gel base for ease of application. Ex vivo permeation study revealed enhanced permeation and ∼ 38-fold higher retention in deeper layers of skin from a hybrid micellar gel. In vivo, assessment demonstrated augmented efficacy of APR-HMMG as compared to 0.1 % betamethasone valerate. Also, APR-HMMG showed no sign of irritation, suggesting superior safety as a topical application. Thus, the proposed formulation strategy represents a viable avenue for enhancing the therapeutic efficacy of various anti-psoriatic moieties.

Asiatic acid-entrapped transfersomes for the treatment of hypertrophic scars: In vitro appraisal, bioactivity evaluation, and clinical study

Non-invasive treatment options for hypertrophic scars (HTS) are limited, and treating HTS remains challenging due to their unappealing appearance and associated social stigma. In this work, a novel transfersomal system named Asiatic acid-entrapped transfersomes (AATs) was prepared. AATs were evaluated for their skin permeability, anti-inflammatory activity, and other characteristic parameters to determine the most promising formulation. Asiatic acid-entrapped transfersomal gel (AATG), which was obtained by incorporating the lead AATs in a gel base, underwent testing in an 8-week, double-blind, placebo-controlled, split-skin clinical study. The net skin elasticity (R5), melanin index (MI), and skin surface hydration were analyzed employing Cutometer®, Mexameter®, and Corneometer®, respectively, in order to evaluate the effectiveness of the developed AATG. AATs exhibited vesicular sizes and zeta potential values within the range of (27.15 ± 0.95 to 63.54 ± 2.51 nm) and (-0.010 to -0.129 mV), respectively. TW80AAT gave the highest %EE (90.84 ± 2.99%), deformability index (101.70 ± 11.59 mgs-1), permeation flux at 8 h (0.146 ± 0.005 mg/cm2/h), and anti-inflammatory activity (71.65 ± 1.83%). The clinical study results of AATG indicated no adverse skin reactions. Furthermore, product efficacy tests demonstrated a significant reduction in MI and an increase in net skin elasticity at 2, 4, and 8 weeks. These pilot study outcomes support the effectiveness of the AATG.

Transfersome, an ultra-deformable lipid-based drug nanocarrier: an updated review with therapeutic applications

The application of nanotechnology with integration of chemical sciences is increasing continuously in the management of diseases. The drug's physicochemical and pharmacological characteristics are enhanced by application of nanotechnological principles. Several nanotechnology-based formulations are being investigated to improve patient compliance. One such novel nanocarrier system is transfersome (TFS) and is composed of natural biocompatible phospholipids and edge activators. Morphologically, TFS are similar to liposomes but functionally, these are ultra-deformable vesicles which can travel through pores smaller than their size. Because of their amphipathic nature, TFS have the potential to deliver the drugs through sensitive biological membranes, especially the blood-brain barrier, skin layers, and nasal epithelium. Different molecular weight drugs can be transferred inside the cell by encapsulation into the TFS. Knowing the tremendous potentiality of TFS, the present work provides an in-depth and detailed account (pharmaceutical and preclinical characteristics) of TFS incorporating different categories of therapeutic moieties (anti-diabetic, anti-inflammatory, anti-cancer, anti-viral, anti-fungal, anti-oxidant, cardiovascular drugs, CNS acting drugs, vaccine delivery, and miscellaneous applications). It also includes information about the methods of preparation employed, significance of excipients used in the preparation, summary of clinical investigations performed, patent details, latest investigations, routes of administration, challenges, and future progresses related to TFS.

Probing the effectiveness of barrier creams against human skin penetration of nickel powder

OBJECTIVE

Barrier creams (BCs) are marketed as locally applied medical devices or cosmetic products to protect the skin from exposure to chemicals and irritants. Generally, the mechanism of action of such products is mainly due to the formation of a superficial thin film between the skin and the irritant or sensitizer, thus reducing or totally blocking the cutaneous penetration of such agents. Specifically, studies focusing on the effectiveness of commercial protective creams to prevent nickel cutaneous penetration are extremely scarce. The aim of the current work, therefore, is to evaluate the protective role of a commercially available barrier cream for nickel and compare the results with a simple moisturizing, following exposure to Ni powder.

METHODS

Marketed BCs were evaluated and tested. Human skin absorption of Ni was studied in vitro using static Franz diffusion cells.

RESULTS

Our results demonstrate that the application of both formulations caused a reduction of Ni inside the skin (8.00 ± 3.35 μg cm-2 for the barrier cream and 22.6 ± 12.6 μg cm-2 for the general moisturizing product), with the specialized barrier cream being statistically (p = 0.015) more efficient on forming a protective barrier, thus evidencing the importance of some ingredients in such formulations on the nickel dermal accumulation.

CONCLUSIONS

The composition of the formulations based on film-forming or chelating agents may play an imperative role in reducing the cutaneous penetration of Ni.

Microsponge-Based Gel Loaded with Immunosuppressant as a Simple and Valuable Strategy for Psoriasis Therapy: Determination of Pro-Inflammatory Response through Cytokine IL-2 mRNA Expression

Tacrolimus (TL) is a topical calcineurin inhibitor immunosuppressive drug widely used to manage various skin disorders. Herein, we report a TL-loaded microsphere gel formulation with severe atopic dermatitis effects that are required to manage skin disorders. The current study adopted a modified emulsion solvent evaporation technique to synthesize TL-loaded microspheres, which were further converted into gels for skin use. Characterization of the synthesized formulation was performed by differential dynamic light scattering, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray crystallography, Brunauer-Emmett-Teller (BET) analysis, differential scanning calorimetry, and drug release. A Franz diffusion cell was used to study the diffusion of TL for up to 8 h at pH 6.8 and 5.5. Evaluation of cell viability was determined by MTT assay and showed higher IC50 values compared to the plain drug. RNA extraction, real-time polymerase chain reaction (RT-PCR), and reverse transcription were also performed to determine the expression levels of the anti-inflammatory cytokine IL-2. Particle size determination was performed by a zeta sizer, and the TL microsphere size was 1745 ± 70 nm with a good polydispersity (0.337 ± 0.12). The drug entrapment efficiency was also very good at 60% ± 10, and the drug release was 93.9% ± 3.5 within 8 h. An in vitro diffusion study of the formulation also showed improved permeability at both pH values (4.5 and 5.5). The findings of the hemolytic tests demonstrated that TL-MG at concentrations of 50, 100, and 200 mg/mL did not produce any hemolysis. A dose-dependent pattern of cytotoxicity was found during the cell viability assay, with an IC50 value of 787.55 ± 12.78 µg/mL. There was a significant decrease in the IL-2 level in the TL-MG group compared to the other groups. TL-MG microspheres were nontoxic carriers for tacrolimus delivery, with greater loading capacity, a significant release profile, and enhanced cellular uptake with improved permeability.

Evaluating the role of protective creams on the cutaneous penetration of Ni nanoparticles

There is an increase of application of Nickel in the form of nanoparticles (NiNPs) in several fields including modern metallurgy, bioengineering, and medicine. Such growth of the areas of application is actually accompanied with an increase of exposure to Nickel, thus an intensification of the negative effects, the most frequent being the allergic contact dermatitis. Indeed, due to their smaller size, and therefore their higher surface area, NiNPs can release more Ni ions compared to bulk material, that can penetrate and permeate through the skin. To reduce the Ni cutaneous penetration, barrier creams (BC) are applied on the skin surface. There is little information, however, on the efficiency of such commercial protective creams on decreasing Ni cutaneous penetration. For this reason, the objective of the current study was to investigate the protective role of one commercially available formulation for Ni (Nik-L-Block™ containing a chelating agent) and one moisturizing cream (Ceramol 311 basic cream without chelating agent), following exposure to NiNPs, using in vitro Franz cells, as well as the cytotoxicity of NiNPs in primary human dermal fibroblasts was studied. Our results demonstrated that although both tested formulations can decrease Ni accumulation in the skin (4.13 ± 1.74 μg/cm² for Nik-L-Block™ and 7.14 ± 1.46 μg/cm² for Ceramol 311 basic cream); there are significant differences between the two creams (p = 0.004). Based on the experimental evidence, we therefore conclude that the composition of such formulations has an imperative role for dermal uptake of Ni. Finally, NiNPs showed no cytotoxic effect on cultured human dermal fibroblasts after 24 and 72 h.

Neutral Oil-Incorporated Liposomal Nanocarrier for Increased Skin Delivery of Ascorbic Acid

In this study, a neutral oil-incorporated liposomal system (lipo-oil-some, LOS) was designed to improve the skin absorption of ascorbic acid (Vit C), and the effects of an edge activator and neutral oil on the skin absorption of Vit C were evaluated. As components of the LOS system, sodium deoxycholate, polysorbate 80, and cholesterol were screened as edge activators, and camellia oil, tricaprylin, and grapeseed oil were employed as neutral oils. The LOS systems prepared by the ethanol injection method were spherical in shape, 130-350 nm in size, and had 4-27% Vit C loading efficiency (%). In a skin absorption study using a Franz diffusion cell mounted with porcine skin, the LOS system prepared with sodium deoxycholate (10 w/w% of phospholipid) exhibited 1.2-and 2.9-fold higher absorption than those prepared with polysorbate 80 and cholesterol, respectively. Moreover, the type of neutral oil had a marked effect on the absorption of Vit C; the liposomal system containing camellia oil provided 1.3 to 1.8 times higher flux (45.4 μg/cm²∙h) than vesicles with tricaprylin or grapeseed oil, respectively. The optimized lipid nanocarrier is expected to be a promising tool for promoting the skin absorption of Vit C and improving its dermatological functions.

Transdermal Delivery of 2-PAM as a Tool to Increase the Effectiveness of Traditional Treatment of Organophosphate Poisoning

For the first time, the efficacy of post-exposure treatment of organophosphate (OP) poisoning was increased by transdermal delivery of acetylcholinesterase (AChE) reactivator pyridine-2-aldoxime methochloride (2-PAM) as a preventive countermeasure. By selecting the optimal ratio of components, classical transfersomes (based on soybean phosphatidylcholine and Tween 20) and modified transfersomes (based on soybean phosphatidylcholine, Tween 20 and pyrrolidinium cationic surfactants with different hydrocarbon tail lengths) were obtained for 2-PAM encapsulation. Transfersomes modified with tetradecylpyrrolidinium bromide showed the best results in encapsulation efficiency and sustained release of 2-PAM from vesicles. Using Franz cells, it was found that the incorporation of surfactants into PC liposomes results in a more prolonged release of 2-PAM through the rat skin. Transfersomes containing 2-PAM, after exhaustive physical and chemical characterization, were embedded in a gel based on Carbopol^® 940. A significantly high degree of erythrocyte AChE reactivation (23 ± 7%) was shown for 2-PAM in unmodified transfersomes in vivo. Preliminary transdermal administration of 2-PAM 24 h before emergency post-exposure treatment of OP poisoning leads to an increase in the survival rate of rats from 55% to 90%.

Probing Pharmaceutical Strategies to Promote the Skin Delivery of Asiatic Acid from Hydrogels: Enhancement Effects of Organic Amine Counterions, Chemical Enhancers, and Microneedle Pretreatment

Asiatic acid (AA) is a pentacyclic triterpene isolated from Centella asiatica, holding great promise for treating a variety of skin disorders. However, the dermal application of AA is limited by its poor solubility and permeability. This study aimed to identify a hydrogel formulation for AA and improve its skin penetration by various penetration enhancement methods. Four kinds of hydrogel bases were selected to prepare the AA hydrogel, in which different organic amines and chemical enhancers were incorporated in combination with microneedle pretreatment. The results showed that AA had good release profiles in the presence of hyaluronic acid as the hydrogel base and organic amines as the counter-ions. Diethylamine and Span 80 could promote drug penetration into the skin, and pretreatment with microneedles could further increase the drug permeability. In conclusion, the optimized hyaluronic acid hydrogel has great potential for use in the topical delivery of AA, and its penetration via the skin can be further improved by different pharmaceutical approaches.