Formulation and Evaluation of Organogels Containing Hyaluronan Microparticles for Topical Delivery of Caffeine

Lecithin Organogel: A Promising Carrier for the Treatment of Skin Diseases

Skin is the largest organ of the human body, as it protects the body from the external environment. Nowadays, skin diseases and skin problems are more common, and millions of people are affected daily. Skin diseases are due to numerous infectious pathogens or inflammatory conditions. The increasing demand for theoretical research and practical applications has led to the rising prominence of gel as a semisolid material. To this end, organogels has been widely explored due to their unique composition, which includes organic solvents and mineral or vegetable oils, among others. Organogels can be described as semisolid systems wherein an organic liquid phase is confined within a three-dimensional framework consisting of self-assembled, cross-linked, or entangled gelator fibers. These gels have the ability to undergo significant expansion and retain substantial amounts of the liquid phase, reaching up to 99% swelling capacity. Furthermore, they respond to a range of physical and chemical stimuli, including temperature, light, pH, and mechanical deformation. Notably, due to their distinctive properties, they have aroused significant interest in a variety of practical applications. Organogels favor the significant encapsulation and enhanced permeation of hydrophobic molecules when compared with hydrogels. Accordingly, organogels are characterized into lecithin organogels, pluronic lecithin organogels, sorbitan monostearate-based organogels, and eudragit organogels, among others, based on the nature of their network and the solvent system. Lecithin organogels contain lecithin (natural and safe as a living cell component) as an organogelator. It acts as a good penetration enhancer. In this review, first we have summarized the fundamental concepts related to the elemental structure of organogels, including their various forms, distinctive features, methods of manufacture, and diverse applications. Nonetheless, this review also sheds light on the delivery of therapeutic molecules entrapped in the lecithin organogel system into deep tissue for the management of skin diseases and provides a synopsis of their clinical applications.

Topical caffeine-loaded nanostructured lipid carriers for enhanced treatment of cellulite: A 32 full factorial design optimization and in vivo evaluation in rats

The goal of this study was the development and evaluation of semisolid caffeine (CAF) loaded nanostructured lipid carriers (NLCs) for topical treatment of cellulite. CAF-loaded NLC formulations were prepared via high-speed homogenization followed by ultrasonication. A 32 full factorial design was employed for formulation optimization. The total lipid content (%) and the liquid lipid content per total lipids (%) were chosen as factors, whereas particle size (PS), polydispersity index (PDI), zeta potential (|ZP|) and viscosity (VIS) were selected as responses. The design suggested CAF-NLC3 as the optimum formulation consisting of a total lipid content of 15% w/w (palmitic acid and soft paraffin/isopropyl myristate, 7:3 w/w) and a surfactant content of 10% w/w (Tween 80/lecithin, 8:1.2 w/w). CAF-NLC3 revealed PS, PDI, ZP, VIS and CAF content values of 318.8 nm, 0.253, -41.1 mV, 18.0 Pa.s and 97.57%, respectively. It showed a pseudoplastic rheological behavior, acceptable pH value (5.25), good spreadability (1.12 mm2/g) and spherical shape employing transmission electron microscopy. Differential scanning calorimetry and X-ray diffraction demonstrated the amorphization of CAF in CAF-NLC3. CAF-NLC3 remained stable for 3 months at room and refrigeration conditions. A single topical application of CAF-NLC3 on shaved abdominal skins of Wistar rats revealed enhanced skin retention of CAF by 2-fold and 1.4-fold after 4 h when compared with plain CAF gel (CAF-P) and marketed CAF gel (CAF-M), respectively. Furthermore, CAF-NLC3 exhibited a superior anti-cellulite activity in comparison with CAF-P and CAF-M through elevating extracellular matrix components (collagen 1, elastin and hyaluronic acid) and stimulating the brown adipose tissue thermogenesis via up-regulating UCP1 and PPAR-γ expression. In addition, CAF-NLC3 prominently increased lipolysis through HSL activity and decreased pro-inflammatory cytokines such as ICAM-1 and VCAM-1 after 30 days of treatment on a high fat diet-induced cellulite rat model. These findings were further confirmed by histopathological examination supported by morphometric analysis. Therefore, incorporation of CAF in a semisolid NLC formulation would be a promising cosmetic approach for the topical treatment of cellulite.

Enhanced intradermal delivery of Dragon's blood in biocompatible nanosuspensions hydrogel patch for skin photoprotective effect

Dragon's Blood is a member of the Chinese medicinal herb, having anti-oxygen and anti-inflammatory activity for the photoprotective effect. However, the poor water solubility of raw Dragon's Blood powder has limited its intradermal delivery process. In this study, we evaluated nanosuspensions to enhance intradermal delivery of Dragon's Blood exerting a photoprotective effect. The prepared nanosuspension was added to a composite hydrogel patch matrix for better skin application. In the present research, we used biocompatible materials hyaluronic acid and amino acid surfactants as nanosuspension stabilizers and agar/gelatin/sodium polyacrylate as hydrogel patch matrix. The prepared Dragon's Blood nanosuspension had a particle size of 447.0 ± 48.6 nm. The micro-structures morphology and viscoelasticity characteristics by SEM and rheological testing confirmed a sufficient crosslinked hydrogel network. The skin retention amount of Dragon's Blood nanosuspension was 1.48 times of raw Dragon's Blood powder water suspension, and the skin penetration amount of Dragon's Blood nanosuspension was only about 1/3 of Dragon's Blood DMSO solution. In the UVB-irradiated HaCaT cell phototoxicity model, Dragon's Blood nanosuspension also significantly increased cell viability by about 1 time of the model group and decreased the production of reactive oxygen species about 1/2 times of model group. In vivo safety and efficiency evaluation experiment illustrated that DB-NS hydrogel patch processes have favorable safety and photoprotective effect with no skin irritancy and phototoxicity. Furthermore, DB-NS and DB-NS hydrogel patches could protect skin from UVA and UVB irritating skin reactions. Overall, our study of the combined use of biocompatible and biodegradable materials as excipients of nanosuspension and hydrogel patch could be used as an effective additive of Intradermal delivery and skin photoprotection.

Helwah MK, Noureldin MH, Abbas H. Dual-effects of caffeinated hyalurosomes as a nano-cosmeceutical gel counteracting UV-induced skin ageing

Caffeine (CAF) is a challenging natural bioactive compound with proven antiaging efficacy. However, being hydrophilic hampers its permeation through the skin. Our aim is to develop a novel CAF-loaded nano-cosmeceutical tool counteracting skin photoaging via improving CAF skin permeation using a bioactive nanocarrier. Caffeinated hyalurosomes are novel biocompatible antiaging nanoplatforms designed by immobilization of phospholipid vesicles with a hyaluronan polymer. Physicochemical properties of the selected hyalurosomes formulation showed nano-sized vesicles (210.10 ± 1.87 nm), with high zeta potential (-31.30 ± 1.19 mv), and high encapsulation efficiency (84.60 ± 1.05%). In vitro release results showed outstanding sustained release profile from caffeinated hyalurosomes compared to the CAF-loaded in conventional gel over 24 h. The in-vivo study revealed a photoprotective effect of caffeinated hyalurosomes, reflected from the intact and wrinkling-free skin. Results of biochemical analyses of oxidative stress, pro-inflammatory mediators, and anti-wrinkling markers further confirmed the efficacy of the prepared hyalurosomes compared to the CAF conventional gel. Finally, histopathological examination demonstrated normal histological structures of epidermal layers with minimal inflammatory cell infiltrates in the caffeinated hyalurosomes group compared to the positive control group. Conclusively, caffeinated hyalurosomes successfully achieved enhanced CAF loading and penetration into the skin besides the hydration effect of hyaluronan. Consequently, the developed delivery system presents a promising skin protection nano-platforms via the double effects of both hyaluronan and CAF, hence it guards against skin photodamage.

Development of SEDDS formulation containing caffeine for dermal delivery

OBJECTIVE

The objective of this work was to develop a self-emulsifying drug delivery system (SEDDS) containing caffeine for the treatment of cellulite.

METHODS

SEDDS were prepared using the solution method. 0.5% (w/v) caffeine was added to the previously selected excipients. The system was characterized by droplet size, zeta potential, emulsification time and long-term stability. In vitro release and skin permeation were investigated using Franz-type diffusion cells. The cytotoxicity was evaluated on normal human keratinocytes.

RESULTS

Caffeine SEDDS were thermodynamically stable, with a zeta potential less than - 22 mV and droplet size around 30 nm, and were long-term stable. The permeation study showed that the formulation promoted caffeine accumulation in the skin layers, suggesting an increase in local circulation. Cytotoxicity studies on HaCaT cells were not conclusive as the surfactant used indicated false-positive results due to its high molar mass.

CONCLUSION

It was possible to obtain a stable SEDDS that could cause an increase in blood flow in the applied area, resulting in cellulite reduction.

A Review of Potential Use of Amazonian Oils in the Synthesis of Organogels for Cosmetic Application

New strategies for the delivery of bioactives in the deeper layers of the skin have been studied in recent years, using mainly natural ingredients. Among the strategies are organogels as a promising tool to load bioactives with different physicochemical characteristics, using vegetable oils. Studies have shown satisfactory skin permeation, good physicochemical stability mainly due to its three-dimensional structure, and controlled release using vegetable oils and low-molecular-weight organogelators. Within the universe of natural ingredients, vegetable oils, especially those from the Amazon, have a series of benefits and characteristics that make them unique compared to conventional oils. Several studies have shown that the use of Amazonian oils brings a series of benefits to the skin, among which are an emollient, moisturizing, and nourishing effect. This work shows a compilation of the main Amazonian oils and their nutraceutical and physicochemical characteristics together with the minority polar components, related to health benefits, and their possible effects on the synthesis of organogels for cosmetic purposes.

Ground coffee waste-derived carbon for adsorptive removal of caffeine: Effect of surface chemistry and porous structure

Carbon-based adsorbents show high adsorption capacity towards caffeine due to their porosity and surface functionality. However, the main limiting factor for high performance has not been addressed; furthermore, the adsorption interaction with different active sites needs to be explored. In this study, we synthesized a hierarchical porous nitrogen-doped carbon with unique surface functionality by single-step calcination of coffee waste with KOH under N₂. The porous structure, nitrogen content, and types are optimized by varying calcination temperature and KOH concentration. The result of the adsorption experiments shows that both the nitrogen type and the pore size distribution are the limiting factors to adsorption. In addition, the effect of acidic and basic functional groups is studied in detail. The adsorption of caffeine on CW-C is dominantly governed by EDA interaction between the resonance structure of pyridonic-N and the electron-withdrawing group of the caffeine, and the dispersive force caused by the oxidized-N and delocalized π electron of caffeine. Furthermore, we demonstrate that the surface of CW-C is not suitable for the formation of electrostatic and non-electrostatic interaction with caffeine. The maximum adsorption capacity of caffeine at 25 °C is 274.2 mg/g. Moreover, we demonstrate that the unique physio-chemical properties of CW-C are capable of adsorbing other emerging contaminants such as diclofenac, where maximum adsorption capacity of 242.3 mg/g diclofenac is recorded.

Application of Solvent Parameters for Predicting Organogel Formation

Solvents, accounting the majority of the organogel system, have a tremendous impact on the characteristics of gels. To date, there is a large variety of organogel systems; relatively few have been investigated in the field of structure-solvent correlation. Here, a series of solvent parameters were applied to explore the role of solvent effect on network forming and gel property, intending to build the connection between the precise solvent parameter and gel property. Among the solvent parameters, Kamlet-Taft Parameters and Hansen solubility parameters can distinguish specific types of intermolecular interactions, which could correlate solvent parameter with the gel property. From an analysis of the morphologies obtained from POM and SEM, the gelator structure has an impact on its self-assembly. For possible conformations, the gelators were investigated through XRD. The investigation of solvent-property relationship will provide a theoretical basis for controllable drug delivery implants.

Hyaluronic Acid in the Third Millennium

Since its first isolation in 1934, hyaluronic acid (HA) has been studied across a variety of research areas. This unbranched glycosaminoglycan consisting of repeating disaccharide units of N-acetyl-d-glucosamine and d-glucuronic acid is almost ubiquitous in humans and in other vertebrates. HA is involved in many key processes, including cell signaling, wound reparation, tissue regeneration, morphogenesis, matrix organization and pathobiology, and has unique physico-chemical properties, such as biocompatibility, biodegradability, mucoadhesivity, hygroscopicity and viscoelasticity. For these reasons, exogenous HA has been investigated as a drug delivery system and treatment in cancer, ophthalmology, arthrology, pneumology, rhinology, urology, aesthetic medicine and cosmetics. To improve and customize its properties and applications, HA can be subjected to chemical modifications: conjugation and crosslinking. The present review gives an overview regarding HA, describing its history, physico-chemical, structural and hydrodynamic properties and biology (occurrence, biosynthesis (by hyaluronan synthases), degradation (by hyaluronidases and oxidative stress), roles, mechanisms of action and receptors). Furthermore, both conventional and recently emerging methods developed for the industrial production of HA and its chemical derivatization are presented. Finally, the medical, pharmaceutical and cosmetic applications of HA and its derivatives are reviewed, reporting examples of HA-based products that currently are on the market or are undergoing further investigations.