Bakuchiol nanoemulsion loaded electrospun nanofibers for the treatment of burn wounds

The present work aims to develop and evaluate the wound healing potential of bakuchiol nanoemulsion loaded electrospun scaffolds. Since oxidative stress and microbial burden leads the burn wounds to become chronic and fatal to patients, a phytoconstituent, bakuchiol (BAK), was screened on the basis of antioxidant and antimicrobial potential which also defined its dose. Furthermore, BAK was incorporated into a nanoemulsion to enhance its therapeutic efficacy, reduce its dosage frequency, and maximize its stability. The present study is inclined towards the collaborative interaction of natural products and novel drug delivery systems to develop safe and therapeutically efficient systems for burn wound healing. The optimized nanoemulsion showed excellent antioxidant and antimicrobial potential against wound susceptible pathogens, i.e., Candida albicans and Methicillin-resistant Staphylococcus aureus which was further loaded into gelatin based hydrogel and nanofibrous scaffold system. The mesh structure of scaffolds was chosen as a suitable carrier system for wound healing process not only because it offers resemblance to skin's anatomy but is also capable of providing uniform distribution of wound biomarkers across the skin. The prepared nanofibers were assessed for their analgesic, anti-inflammatory, and wound healing potential which was observed to be significantly better than its gel formulation.

Artemisia monosperma essential oil nanoformulations alleviate imiquimod-induced psoriasis-like dermatitis in mice

Psoriasis is an inflammatory immune-mediated skin disease that affects nearly 2-3 % of the global population. The current study aimed to develop safe and efficient anti-psoriatic nanoformulations from Artemisia monosperma essential oil (EO). EO was extracted using hydrodistillation (HD), microwave-assisted hydrodistillation (MAHD), and head-space solid-phase microextraction (HS-SPME), as well as GC/ MS was used for its analysis. EO nanoemulsion (NE) was prepared using the phase inversion method, while the biodegradable polymeric film (BF) was prepared using the solvent casting technique. A.monosperma EO contains a high percentage of non-oxygenated compounds, being 90.45 (HD), 82.62 (MADH), and 95.17 (HS-SPME). Acenaphthene represents the major aromatic hydrocarbon in HD (39.14 %) and MADH (48.60 %), while sabinene as monoterpene hydrocarbon (44.2 %) is the primary compound in the case of HS-SPME. The anti-psoriatic Effect of NE and BF on the successful delivery of A.monosperma EO was studied using the imiquimod (IMQ)-induced psoriatic model in mice. Five groups (n = 6 mice) were classified into control group, IMQ group, IMQ+standard group, IMQ+NE group, and IMQ+BF group. NE and BF significantly alleviated the psoriatic skin lesions and decreased the psoriasis area severity index, Baker's score, and spleen index. Also, they reduced the expression of Ki67 and attenuated the levels of tumor necrosis factor-alpha, interleukin 6, and interleukin 17. Additionally, NE and NF were able to downregulate the NF-κB and GSK-3β signaling pathways. Despite the healing properties of BF, NE showed a more prominent effect on treating the psoriatic model, which could be referred to as its high skin penetration ability and absorption. These results potentially contribute to documenting experimental and theoretical evidence for the clinical uses of A.monosperma EO nanoformulations for treating psoriasis.

Therapeutic potential of limonene-based syringic acid nanoemulsion: Enhanced ex-vivo cutaneous deposition and clinical anti-psoriatic efficacy

Nanoemulsions have carved their position in topical delivery owing to their peculiar features of forming a uniform film on the skin and conquering stratum corneum barrier and hence fostering dermal penetration and retention. The present work developed syringic acid nanoemulsion (SA-NE) by spontaneous emulsification as an anti-psoriatic remedy via the dermal route. SA-NE were prepared with either lauroglycol90, limonene or their combination (oil phase) and tween80 (surfactant) with variable concentrations. The physicochemical characteristics of SA-NE were assessed together with Ex-vivo skin deposition and dermal toxicity. The effectiveness of optimal formula in psoriatic animal model and psoriatic patients was investigated using PASI scoring and dermoscope examination. Results showed that, SA-NE containing mixture of lauroglycol 90, limonene and 10 % tween80 (F5), was selected as the optimal formula presenting stable nanoemulsion for 2-month period, showing droplet size of 177.6 ± 13.23 nm, polydispersity index of 0.16 ± 0.06, zeta potential of -21.23 ± 0.41 mV. High SA% in different skin strata and no dermal irritation was noticed with limonene-based SA-NE also it showed high in-vitro anti- inflammatory potential compared to the blank and control formulations. A preclinical study demonstrated that limonene-based SA-NE is effective in alleviating psoriasis-like skin lesions against imiquimod-induced psoriasis in rats. Clinically, promising anti-psoriatic potential was asserted as all patients receiving F5 experienced better clinical improvement and response to therapy, achieving ≥ 50 % reduction in PASI scores versus only 35 % responders in the Dermovate® cream group. Collectively, the practical feasibility of limonene-based SA-NE topical delivery can boost curative functionality in the treatment of psoriatic lesions.

Recent Approaches for the Topical Treatment of Psoriasis Using Nanoparticles

Psoriasis (PSO) is a chronic autoimmune skin condition characterized by the rapid and excessive growth of skin cells, which leads to the formation of thick, red, and scaly patches on the surface of the skin. These patches can be itchy and painful, and they may cause discomfort for patients affected by this condition. Therapies for psoriasis aim to alleviate symptoms, reduce inflammation, and slow down the excessive skin cell growth. Conventional topical treatment options are non-specific, have low efficacy and are associated with adverse effects, which is why researchers are investigating different delivery mechanisms. A novel approach to drug delivery using nanoparticles (NPs) shows promise in reducing toxicity and improving therapeutic efficacy. The unique properties of NPs, such as their small size and large surface area, make them attractive for targeted drug delivery, enhanced drug stability, and controlled release. In the context of PSO, NPs can be designed to deliver active ingredients with anti-inflammatory effect, immunosuppressants, or other therapeutic compounds directly to affected skin areas. These novel formulations offer improved access to the epidermis and facilitate better absorption, thus enhancing the therapeutic efficacy of conventional anti-psoriatic drugs. NPs increase the surface-to-volume ratio, resulting in enhanced penetration through the skin, including intracellular, intercellular, and trans-appendage routes. The present review aims to discuss the latest approaches for the topical therapy of PSO using NPs. It is intended to summarize the results of the in vitro and in vivo examinations carried out in the last few years regarding the effectiveness and safety of nanoparticles.

Formulation of Piperine-Loaded Nanoemulsion: In Vitro Characterization, Ex Vivo Evaluation, and Cell Viability Assessment

Piperine is an alkaloid, but its therapeutic efficacy is limited due to poor aqueous solubility. In this study, piperine nanoemulsions were prepared using oleic acid (oil), Cremophore EL (surfactant), and Tween 80 (co-surfactant) using the high-energy ultrasonication approach. The optimal nanoemulsion (N2) was further evaluated using transmission electron microscopy, release, permeation, antibacterial, and cell viability studies based on minimal droplet size and maximum encapsulation efficiency. The prepared nanoemulsions (N1-N6) showed a transmittance of more than 95%, a mean droplet size between 105 ± 4.11 and 250 ± 7.4 nm, a polydispersity index of 0.19 to 0.36, and a ζ potential of -19 to -39 mV. The optimized nanoemulsion (N2) showed significantly improved drug release and permeation compared with pure piperine dispersion. The nanoemulsions were stable in the tested media. The transmission electron microscopy image showed a spherical and dispersed nanoemulsion droplet. The antibacterial and cell line results of piperine nanoemulsions were significantly better than the pure piperine dispersion. The findings suggested that piperine nanoemulsions may be a more advanced nanodrug delivery system than conventional ones.

Babchi Oil-Based Nanoemulsion Hydrogel for the Management of Psoriasis: A Novel Energy Economic Approach Employing Biosurfactants

The current research aimed to assess the Babchi oil nanoemulsion-based hydrogel prepared using biosurfactants through a low-energy emulsification process for the topical management of psoriasis. The emulsification capacity and solubilities of many nanoemulsion constituents such as surfactants, co-surfactants, and oil were considered to determine the range of concentration of the constituents. Pseudoternary phase diagrams were created using the method of titration. Nanoemulgel structure, morphology, micromeritics, conductivity, and viscosity were all optimized. The assessment of the Babchi oil nanoemulgel included particle size, polydispersity index (PDI), drug content, pH, spreadability, rheological management, ex vivo drug study, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, in vitro drug release, release kinetics, and dermatokinetics. The selected ratios of the surfactant mixture (Smix) taken were 3:1. The entrapment efficiency estimated was 91.298%. The zeta potential of Babchi oil was observed to be -24.93 mV at 25 °C with water as a dispersant, viscosity as 0.887 cP, and material absorption as 0.01 nm. The size distribution of the particle was 108 nm by the intensity and the conductivity observed was 0.03359 mS/cm. The cumulative amount of Babchi oil penetrated and fluxed by nanoemulgel was considered larger (p ≤ 0.05) than the conventional formulations. Skin retention was observed to be good with decreased lag time. The formulation followed the Higuchi Korsmeyer for Fickian Peppas model for in vitro drug release studies. The oil was most effective on the epidermal layer of the skin for treatment. It was established that the Babchi oil nanoemulgel formulation had superior permeability capabilities for topical and transdermal administration and is a viable alternative to traditional formulations.

Production of Minor Ginsenoside CK from Major Ginsenosides by Biotransformation and Its Advances in Targeted Delivery to Tumor Tissues Using Nanoformulations

For over 2000 years, ginseng (roots of Panax ginseng C.A. Meyer) has been used as a traditional herbal medicine. Ginsenosides are bioactive compounds present in ginseng responsible for the pharmacological effects and curing various acute diseases as well as chronic diseases including cardiovascular disease, cancer and diabetes. Structurally, ginsenosides consist of a hydrophobic aglycone moiety fused with one to four hydrophilic glycoside moieties. Based on the position of sugar units and their abundance, ginsenosides are classified into major and minor ginsenosides. Despite the great potential of ginsenosides, major ginsenosides are poorly absorbed in the blood circulation, resulting in poor bioavailability. Interestingly, owing to their small molecular weight, minor ginsenosides exhibit good permeability across cell membranes and bioavailability. However, extremely small quantities of minor ginsenosides extracted from ginseng plants cannot fulfill the requirement of scientific and clinical studies. Therefore, the production of minor ginsenosides in mass production is a topic of interest. In addition, their poor solubility and lack of targetability to tumor tissues limits their application in cancer therapy. In this review, various methods used for the transformation of major ginsenosides to minor ginsenoside compound K (CK) are summarized. For the production of CK, various transformation methods apply to major ginsenosides. The challenges present in these transformations and future research directions for producing bulk quantities of minor ginsenosides are discussed. Furthermore, attention is also paid to the utilization of nanoformulation technology to improve the bioavailability of minor ginsenoside CK.

Synthesis and Characterization of Chitosan-Decorated Nanoemulsion Gel of 5-Fluorouracil for Topical Delivery

(1) Background: The present study aimed to prepare chitosan-coated nanoemulsion gel containing 5-fluorouracil for enhanced topical delivery. (2) Methods: To formulate the nanoemulsion gel, oleic acid was used as the oil phase and Carbopol 940 as a gelling agent. Chitosan was used as a coating agent to control the release of 5-FU. Drug−excipient compatibility was evaluated using ATR-FTIR. The prepared nanoemulsion formulations were characterized based on particle size distribution, zeta potential, % encapsulation efficiency and drug content. In vitro drug release, skin drug retention and ex vivo permeation profiles were performed across rat skin using a Franz diffusion cell. Skin irritation experiments were also conducted on rats to examine the irritation potential of the formulations. (3) Results: It was found that the drug and excipients were compatible and chitosan successfully coated 5-FU, as demonstrated by ATR-FTIR results. The introduction of chitosan increased the size and zeta potential of the nanoemulsion. The 5-FU release in vitro was significantly lowered in the case of chitosan-decorated nanoemulsion (5-FU-C-NE), whereas the permeation and skin drug retention were higher in the case of 5-FU-C-NE. The formulations were proven non-irritant to the skin of the rats. The optimized formulation of the nanoemulsion was introduced into 1% Carbopol 940 gel. Incorporating the nanoemulsion into the gel further reduced the drug release in vitro and ex vivo permeation, whereas the retention of the drug in the skin was significantly increased (ANOVA; p < 0.05). The increase in skin retention was due to the presence of chitosan and Carbopol 940. The in vitro and ex vivo results were also confirmed with in vivo studies. Incorporating nanoemulsion into gel has resulted in higher Tmax, longer half-life and greater skin drug retention. (4) Conclusion: The results suggest that chitosan-decorated nanoemulsion gel is safe and can potentially be used to promote 5-FU skin retention, which is ideal for skin diseases such as melanoma.

Topical Application of Tetrandrine Nanoemulsion Promotes the Expansion of CD4+Foxp3+ Regulatory T Cells and Alleviates Imiquimod-Induced Psoriasis in Mice

There is compelling evidence that CD4⁺Foxp3⁺ regulatory T cells (Tregs) are indispensable in the inhibition of autoimmune inflammatory responses, including psoriasis. Recently, we showed that systemically treatment with tetrandrine (TET), a two-pore channel inhibitor identified from the Chinese herb Stephania tetrandra S. Moor, could promote the proliferative expansion of Tregs in mice through stimulation of TNF-TNFR2 interaction. We thus hypothesized that topical administration of TET might also expand Tregs and consequently inhibit psoriasis. To this end, we developed a TET nanoemulsion and examined its effect on the expansion of Tregs after topical administration on mouse psoriasis induced by imiquimod. The result of our experiment showed that topical treatment with TET nanoemulsion markedly increased the proportion and number of Tregs in the spleen, as well as TNFR2 and Ki-67 expression by Tregs, in WT and TNFR1 KO mice, but not in TNFR2 KO mice. Consequently, TET nanoemulsion potently inhibited IL-17-expressing cells in the spleen and lymph nodes of imiquimod-treated WT mice, accompanied by decreased serum levels of IL-17A, INF-γ, and TNF and their mRNA levels in the flamed lesion. Importantly, TET nanoemulsion treatment markedly inhibited the development of psoriasis-like disease in WT and TNFR1 KO mice but not in TNFR2 KO mice. Therefore, our study indicates that the topical administration of TET could also stimulate the expansion of Tregs through the TNF-TNFR2 pathway. This effect of TET and its analogs may be useful in the treatment of inflammatory skin diseases such as psoriasis.

Olive oil and clove oil-based nanoemulsion for topical delivery of terbinafine hydrochloride: in vitro and ex vivo evaluation

In this article, formulation studies for terbinafine hydrochloride nanoemulsions, prepared by high-energy ultrasonication technique, are described. Pseudo-ternary phase diagram was constructed in order to find out the optimal ratios of oil and surfactant/co-solvent mixture for nanoemulsion production. Clove and olive oils were selected as oil phase. Based on the droplet size evaluation, maximum nanoemulsion region were determined for formulation development. Further characterization included polydispersity index (PDI), zeta potential, Fourier transform infrared (FT-IR) spectroscopy, morphology, pH, viscosity, refractive index, ex vivo skin permeation, skin irritation, and histopathological examination. Droplet sizes of optimized formulations were in colloidal range. PDI values below 0.35 indicated considerably homogeneous nanoemulsions. Zeta potential values were from 13.2 to 18.1 mV indicating good stability, which was also confirmed by dispersion stability studies. Ex vivo permeation studies revealed almost total skin permeation of terbinafine hydrochloride from the nanoemulsions (96–98%) in 6 hours whereas commercial product reached only 57% permeation at the same time. Maximum drug amounts were seen in epidermis and dermis layers. Skin irritation and histopathological examination demonstrated dermatologically safe formulations. In conclusion, olive oil and clove oil-based nanoemulsion systems have potential to serve as promising carriers for topical terbinafine hydrochloride delivery.

Mimic Nature Using Chemotaxis of Ionic Liquid Microdroplets for Drug Delivery Purposes

Due to the growing prevalence of incurable diseases, such as cancer, worldwide, nowadays, the development of smart drug delivery systems is an inevitable necessity. Chemotaxis-driven movement of ionic liquid microdroplets containing therapeutic compounds is a well-known example of a smart drug delivery system. This review aims to classify, summarize, and compare ionic liquid-based chemotaxis systems in an easily understandable article. Chemotaxis is the basis of the movement of cells and microorganisms in biological environments, which is the cause of many vital biochemical and biological processes. This review attempts to summarize the available literature on single-component biomimetic and self-propelling microdroplet systems based on ionic liquids, which exhibit chemotaxis and spontaneously move in a determined direction by an external gradient, particularly a chemical change. It also aims to review artificial ionic liquid-based chemotaxis systems that can be used as drug carriers for medical purposes. The various ionic liquids used for this purpose are discussed, and different forms of chemical gradients and mechanisms that cause movement in microfluidic channels will be reviewed.

Preparation of eugenol nanoemulsions for antibacterial activities

Eugenol is a versatile plant essential oil, but its high volatility and low water solubility greatly limit its application. Accordingly, this study prepared eugenol nanoemulsions by a high-speed shearing technique. Through visual inspection and a series of characterizations, including dynamic light scattering, and confocal laser scanning microscopy, the optimized formula was determined to be 5% (w/w) oil phase (eugenol) and 8% (w/w) surfactant (Tween-80), and the optimized shearing time was 5 min. The optimized nanoemulsion had good stability, small droplets (85 nm), and uniform distribution. At a concentration of 0.02 mg μL-1, the nanoemulsion showed strong inhibition against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Scanning electron microscopy (SEM) images showed severe deformation and membrane rupture of both bacteria treated by the nanoemulsion. This result was further confirmed by the leakage of proteins in both bacteria after treatment. The results of reactive oxygen species (ROS) and malondialdehyde (MDA) measurements indicated that the increased levels of ROS in both bacteria treated by the nanoemulsion triggered lipid peroxidation, thus increasing the MDA levels, ultimately causing changes in cell membrane permeability and disruption of the membrane structure. In addition, the nanoemulsion had a small effect on the proliferation and apoptosis of hepatocytes (L02) and lung cells (BEAS-2B), indicating its good biocompatibility. In this study, we developed a novel eugenol nanoemulsion with high stability and good biological activity, which may provide a promising and effective method for wound treatment in the healthcare area.

Formulation and characterization of propolis and tea tree oil nanoemulsion loaded with clindamycin hydrochloride for wound healing: In-vitro and in-vivo wound healing assessment

This study aimed to develop propolis and tea tree oil nanoemulsion loaded with clindamycin hydrochloride to heal wound effectively. Nanoemulsion formulae were prepared and characterized by droplet size analysis, zeta potential, viscosity, ex-vivo permeation, and skin deposition. The optimal formula was evaluated in terms of morphology, cytotoxicity, and in-vitro wound healing assay. Also, the efficacy of the optimal formula was evaluated by in-vivo wound healing and histopathological studies. The optimal formula (F3) was composed of 9% tea tree oil and 0.4% propolis extracts with mean droplet size 19.42 ± 1.7 nm, zeta potential value −24.5 ± 0.2 mV, and viscosity 69.4 ± 1.8 mP. Furthermore, the optimal formula showed the highest skin deposition value 550.00 ± 4.9 µg/cm² compared to other formulae. The TEM micrograph of the optimal formula showed that the nanoemulsion droplet has an almost spherical shape. Also, the optimal formula did not show noticeable toxicity to the human skin fibroblast cells. The in-vitro and in-vivo wound healing assay showed unexpected results that the un-loaded drug nanoemulsion formula had a comparable wound healing efficacy to the drug-loaded nanoemulsion formula. These results were confirmed with histopathological studies. Our results showed that the propolis and tea tree oil nanoemulsion, whether loaded or unloaded with an antibiotic, is an efficient local therapy for wound healing.

Lipid-based nanoparticles for psoriasis treatment: a review on conventional treatments, recent works, and future prospects

Psoriasis is a lingering inflammatory skin disease that attacks the immune system. The abnormal interactions between T cells, immune cells, and inflammatory cytokines causing the epidermal thickening. International guidelines have recommended topical treatments for mild to moderate psoriasis whilst systemic and phototherapy treatments for moderate to severe psoriasis. However, current therapeutic approaches have a wider extent to treat moderate to severe type of psoriasis especially since the emergence of diverse biologic agents. In the meantime, topical delivery of conventional treatments has prompted many unsatisfactory effects to penetrate through the skin (stratum corneum). By understanding the physiology of stratum corneum barrier functions, scientists have developed different types of lipid-based nanoparticles like solid lipid nanoparticles, nanostructured lipid carriers, nanovesicles, and nanoemulsions. These novel drug delivery systems help the poorly solubilised active pharmaceutical ingredient reaches the targeted site seamlessly because of the bioavailability feature of the nanosized molecules. Lipid-based nanoparticles for psoriasis treatments create a paradigm for topical drug delivery due to their lipids' amphiphilic feature to efficiently encapsulate both lipophilic and hydrophilic drugs. This review highlights different types of lipid-based nanoparticles and their recent works of nano formulated psoriasis treatments. The encapsulation of psoriasis drugs through lipid nanocarriers unfold numerous research opportunities in pharmaceutical applications but also draw challenges for the future development of nano drugs.

Nanoemulsions: A Review on the Conceptualization of Treatment for Psoriasis Using a 'Green' Surfactant with Low-Energy Emulsification Method

Psoriasis is a skin disease that is not lethal and does not spread through bodily contact. However, this seemingly harmless condition can lead to a loss of confidence and social stigmatization due to a persons' flawed appearance. The conventional methods of psoriasis treatment include taking in systemic drugs to inhibit immunoresponses within the body or applying topical drugs onto the surface of the skin to inhibit cell proliferation. Topical methods are favored as they pose lesser side effects compared to the systemic methods. However, the side effects from systemic drugs and low bioavailability of topical drugs are the limitations to the treatment. The use of nanotechnology in this field has enhanced drug loading capacity and reduced dosage size. In this review, biosurfactants were introduced as a 'greener' alternative to their synthetic counterparts. Glycolipid biosurfactants are specifically suited for anti-psoriatic application due to their characteristic skin-enhancing qualities. The selection of a suitable oil phase can also contribute to the anti-psoriatic effect as some oils have skin-healing properties. The review covers the pathogenic pathway of psoriasis, conventional treatments, and prospective ingredients to be used as components in the nanoemulsion formulation. Furthermore, an insight into the state-of-the-art methods used in formulating nanoemulsions and their progression to low-energy methods are also elaborated in detail.

Polymeric Gels and Their Application in the Treatment of Psoriasis Vulgaris: A Review

Psoriasis is a chronic skin disease, and it is especially characterized by the occurrence of red, itchy, and scaly eruptions on the skin. The quality of life of patients with psoriasis is decreased because this disease remains incurable, despite the rapid progress of therapeutic methods and the introduction of many innovative antipsoriatic drugs. Moreover, many patients with psoriasis are dissatisfied with their current treatment methods and the form with which the drug is applied. The patients complain about skin irritation, clothing stains, unpleasant smell, or excessive viscosity of the preparation. The causes of these issues should be linked with little effectiveness of the therapy caused by low permeation of the drug into the skin, as well as patients’ disobeying doctors’ recommendations, e.g., concerning regular application of the preparation. Both of these factors are closely related to the physicochemical form of the preparation and its rheological and mechanical properties. To improve the quality of patients’ lives, it is important to gain knowledge about the specific form of the drug and its effect on the safety and efficacy of a therapy as well as the patients’ comfort during application. Therefore, we present a literature review and a detailed analysis of the composition, rheological properties, and mechanical properties of polymeric gels as an alternative to viscous and greasy ointments. We discuss the following polymeric gels: hydrogels, oleogels, emulgels, and bigels. In our opinion, they have many characteristics (i.e., safety, effectiveness, desired durability, acceptance by patients), which can contribute to the development of an effective and, at the same time comfortable, method of local treatment of psoriasis for patients.

Vesicular systems for dermal and transdermal drug delivery

Dermal/transdermal drug delivery continues to grow in importance as a means of enhancing treatment activity while reducing toxicity by avoiding the systemic absorption of the drug. At the same time, this has led to the adjustment of a wide diversity of drug carriers. This paper begins with a review of the skin, including its structure and the parameters that influence drug diffusion, followed by strategies to improve dermal drug delivery. Of the multitude of existing carriers, we will focus on the most advanced vectors in dermal/transdermal delivery, and in particular, on vesicular systems. This review will present the state of the art as well as the new trends in this domain. Through the description of these systems, we will try to obtain information on the ideal properties that the carrier must have in order to improve the cutaneous and transcutaneous penetration of the drug.

Supramolecular and Macromolecular Matrix Nanocarriers for Drug Delivery in Inflammation-Associated Skin Diseases

Skin is our biggest organ. It interfaces our body with its environment. It is an efficient barrier to control the loss of water, the regulation of temperature, and infections by skin-resident and environmental pathogens. The barrier function of the skin is played by the stratum corneum (SC). It is a lipid barrier associating corneocytes (the terminally differentiated keratinocytes) and multilamellar lipid bilayers. This intricate association constitutes a very cohesive system, fully adapted to its role. One consequence of this efficient organization is the virtual impossibility for active pharmaceutical ingredients (API) to cross the SC to reach the inner layers of the skin after topical deposition. There are several ways to help a drug to cross the SC. Physical methods and chemical enhancers of permeation are a possibility. These are invasive and irritating methods. Vectorization of the drugs through nanocarriers is another way to circumvent the SC. This mini-review focuses on supramolecular and macromolecular matrices designed and implemented for skin permeation, excluding vesicular nanocarriers. Examples highlight the entrapment of anti-inflammatory API to treat inflammatory disorders of the skin.

Synthesis and characterization of novel tamarind gum and rice bran oil-based emulgels for the ocular delivery of antibiotics

In this study, we developed tamarind gum (TG) and rice bran oil (RBO)-based emulgels. The control formulation (TR0), did not contain RBO. The emulgels were named as TR1, TR2, TR3, and TR4, which contained 5% (w/w), 10% (w/w), 15% (w/w), and 20% (w/w/) of RBO, respectively. The microscopic studies showed that the emulgels were biphasic in nature. FTIR spectroscopy revealed the reduction in the hydrogen bonding with an increase in the RBO content. Impedance profiles suggested that the resistive component of the emulgels was increased as the RBO content was increased. The thermal analysis suggested that the addition of RBO reduced the water holding capacity of the emulgels. Stress relaxation studies revealed that the fluidic component was considerably higher in TG/RBO-based emulgels as compared to TR0. In vitro release study of the model drug (ciprofloxacin HCl; a hydrochloride salt of ciprofloxacin) suggested a significantly lower release from the emulgel matrices (TR1-TR4) in comparison to TR0. However, ex vivo corneal permeation of the drug increased with an increase in the RBO content. Since the emulgels were able to improve the corneal permeation of the model drug, the emulgels can be explored to deliver drugs to the internal structures of the eye.

Optimization and Development of Methotrexate- and Resveratrol-Loaded Nanoemulsion Formulation Using Box-Behnken Design for Rheumatoid Arthritis

Methotrexate (MTX) is the first line of choice for the management of rheumatoid arthritis (RA) and has been reported for its low bioavailability and side effects. Combination therapy has been widely investigated to overcome bioavailability issues and to reduce adverse effects associated with monotherapy. Various phytoconstituents such as resveratrol (RSV) and curcumin have been found to possess potent anti-inflammatory activity via downregulating the signaling of cytokines (interleukin [IL]-1, IL-6, and tumor necrosis factor alpha) and nuclear factor kappa B signaling. The prime objective of this study was to develop transdermal gel containing MTX-RSV loaded nanoemulsions (NEs) to overcome bioavailability issues and adverse effects of RA monotherapy. The NEs optimized by using Box-Behnken Design were incorporated within gel, and an in vitro skin permeation study performed on rat skin by using vertical Franz diffusion cells exhibited controlled drug release up to 48 h. Subsequently, anti-inflammatory and potential anti-arthritic activities of the combination in nanocarrier were assessed in rats and showed 78.76 ± 4.16% inhibition in inflammation and better anti-arthritic effects. Consequently, integration of dual delivery with nanotechnology can hopefully produce successful therapeutic options for rheumatic diseases.

Novel rhein-phospholipid complex targeting skin diseases: development, in vitro, ex vivo, and in vivo studies

Rhein (RH), an anthraquinone derivative, has proven to be a promising molecule for treating several skin disorders thanks to its pleiotropic pharmacological activities like antimicrobial, antifungal, antioxidant, and anticancer. However, RH's low water and oil solubility and poor skin permeability halted its topical delivery. This is the first work to investigate the expediency of tailoring a rhein-phospholipid complex (RH-PLC) to improve RH challenging physicochemical and skin permeability properties. The phospholipid complex was prepared by employing different methods and different RH/PL molar ratios. RH-PLC was successfully developed at a stoichiometric ratio of 1:1 using a novel pH-dependent method where at a certain pH, it exhibits the highest complexation efficiency (95%). RH-PLC formation was confirmed using FTIR, DSC, and XRPD analysis. RH-PLC showed a significant increase in water and n-octanol solubility. RH-PLC was self-assembled upon dispersion into water forming nano-sized particles (196.6 ± 1.6 nm) with high negatively charged surface (- 29.7 ± 2.45 mV). RH-PLC exhibited a significant 3.3- and 2.46-fold increase in ex vivo and in vivo skin permeability when compared with RH suspension, respectively. Confocal microscopy study confirmed the ability of RH-PLC to penetrate deeply into rat skin. Besides, skin irritation test on healthy rats indicated compatibility and safety of RH-PLC. Conclusively, phospholipid complex might be a suitable approach to improve permeability of RH and other promising abandoned poor-permeable drugs. The proposed RH-PLC is expected to be a major progressive step toward the development of a topical RH formulation. Graphical abstract.

Preferential Accumulation of Phospholipid-PEG and Cholesterol-PEG Decorated Gold Nanorods into Human Skin Layers and Their Photothermal-Based Antibacterial Activity

Herein, a library of gold nanorods (GNR) decorated with polyethylene glycol-thiol (PEG-SH) containing different functionalities were synthesized and characterized by optical absorption spectroscopy, zeta potential, dynamic light scattering (DLS), transmission electron microscope (TEM) and proton nuclear magnetic resonance (1H-NMR). The colloidal stability of GNR when exposed to skin, and their preferential accumulation into excised human skin layers were investigated. Confocal laser scanning microscopy, transmission electron microscope (TEM) and inductively coupled plasma-optical emission spectroscopy (ICP-OES) were utilized to track the penetration of GNR into different skin layers. The results demonstrated that cholesterol-PEG coated GNR were preferentially loaded up in the upper layers of skin (stratum corneum), while phospholipid-PEG coated counterparts were drastically deposited in skin dermis. Neutral methoxy-PEG-coated GNR were distributed in both SC and dermis skin layers, while charged GNR (anionic-carboxylic acid-PEG-GNR and cationic-amine-PEG-GNR) revealed a minimal accumulation into skin. DSPE-PEG-GNR and Chol-PEG-GNR demonstrated antibacterial activities against Staphylococcus aureus (S aureus) at MIC values of 0.011 nM and 0.75 nM, respectively. Photothermal treatment for S. aureus at sub-MIC concentrations resulted in a significant bactericidal effect when using Chol-PEG-GNR but not DSPE-PEG-GNR. Gold-based nanoscale systems have great value as a promising platform for skin diseases therapy.

Nanoemulsions in drug delivery: formulation to medical application

Nanoscale oil-in-water emulsions (NEs), heterogeneous systems of two immiscible liquids stabilized by emulsifiers or surfactants, show great potential in medical applications because of their attractive characteristics for drug delivery. NEs have been explored as therapeutic carriers for hydrophobic compounds via various routes of administration. NEs provide opportunities to improve drug delivery via alternative administration routes. However, deep understanding of the NE manufacturing and functionalization fundamentals, and how they relate to the choice of administration route and pharmacological profile is still needed to ease the clinical translation of NEs. Here, we review the diversity of medical applications for NEs and how that governs their formulation, route of administration, and the emergence of increasing sophistication in NE design for specific application.

Active natural oil-based nanoemulsion containing tacrolimus for synergistic antipsoriatic efficacy

AIM

The current study is emphasized on development of a nanoemulsion system that simultaneously delivers two antipsoriatic agents viz. Tacrolimus and Kalonji oil (functional excepient) topically.

MATERIALS & METHODS

A nanoemulsion was characterized for quality attributes; a nanoemulsion gel was evaluated for spreadability, viscosity, dermal bioavailability, and in vitro efficacy in A-431 cell line, and so forth. In vivo performance was evaluated on psoriasis model in BALB/c mice.

RESULTS

Nanoemulsion depicted droplet size: 93.37 ± 2.58 nm with PDI (Polydispersity Index) 0.330 ± 0.025. The nanoemulsion gel exhibited desirable spreadability with sustained release pattern (biphasic). Dermal bioavailability enhancement (4.33-fold) accompanied significant in vitro results. A significant reduction in serum cytokines and improvement in psoriatic condition was achieved in vivo, indicating formulation efficacy compared with marketed formulation (Tacroz Forte, Glenmark Pharmaceuticals Ltd, Maharashtra, India).

CONCLUSION

Nanoemulsion gel thus provides an effective alternative for psoriasis treatment.

A practical framework for implementing Quality by Design to the development of topical drug products: Nanosystem-based dosage forms

Skin has been increasingly recognized as an important drug administration route with topical formulations, offering a targeted approach for the treatment of several dermatological disorders. The effectiveness of this route is hampered by its natural barrier, the stratum corneum (SC), and hence, different strategies have been investigated to improve percutaneous drug transport. The design of nanodelivery systems, aiming at solving skin delivery issues, have been largely explored, due to their potential to revolutionize dermal therapies, improving therapeutic effectiveness and reducing side effects. Apart from nanosystem benefits, the fulfilment of the reproducibility requirements and quality standards still limit their industrial production. The optimization of nanosystem formulation and manufacturing process is complex, usually involving a large number of variables. Therefore, a science- and risk-oriented approach, such as Quality by Design (QbD) will provide a comprehensive and noteworthy knowledge, yielding high quality drug products without extensive regulatory burden. This review aims to set up the basis for QbD development approach, encompassing preliminary and systematic risk assessments, with critical process parameters (CPPs) and critical material attributes (CMAs) identification, of different nanosystems potentially used in dermal therapies.

A Tutorial for Developing a Topical Cream Formulation Based on the Quality by Design Approach

The pharmaceutical industry has entered in a new era, as there is a growing interest in increasing the quality standards of dosage forms, through the implementation of more structured development and manufacturing approaches. For many decades, the manufacturing of drug products was controlled by a regulatory framework to guarantee the quality of the final product through a fixed process and exhaustive testing. Limitations related to the Quality by Test system have been widely acknowledged. The emergence of Quality by Design (QbD) as a systematic and risk-based approach introduced a new quality concept based on a good understanding of how raw materials and process parameters influence the final quality profile. Although the QbD system has been recognized as a revolutionary approach to product development and manufacturing, its full implementation in the pharmaceutical field is still limited. This is particularly evident in the case of semisolid complex formulation development. The present review aims at establishing a practical QbD framework to describe all stages comprised in the pharmaceutical development of a conventional cream in a comprehensible manner.

Nanoemulsion containing 8-methoxypsoralen for topical treatment of dermatoses: Development, characterization and ex vivo permeation in porcine skin

Oral therapy with 8-methoxypsoralen (8-MOP) may cause major side effects, whereas the topical treatment might not be much effective due to the low penetration induced by typical formulations. Therefore, the objectives of this work are the development and characterization of a nanoemulsion (NE) containing 8-MOP together with an ex vivo permeation study, monitored by a validated HPLC-Fluo method, to determine the amount of drug retained in viable skin (epidermis (E) and dermis (D)) and in stratum corneum (SC). The optimized conditions for NE formulation were achieved by full factorial designs (2⁵ and 3²): 60 s and 60% of ultrasound time and potency, respectively; 10 mL of final volume; 2% v/v of oil phase (clove essential oil); and 10% m/v of Poloxamer 407. The NE showed mean droplet diameter of 24.98 ± 0.49 nm, polydispersity index (PDI) of 0.091 ± 0.23, pH values of 6.54 ± 0.06, refractive index of 1.3525 ± 0.0001 and apparent viscosity of 51.15 ± 3.66 mPa at 20 °C. Droplets with nanospherical diameters were also observed by transmission electron microscopy (TEM). Ex vivo permeation study showed that 8.5% of the applied 8-MOP dose permeated through the biological membranes, with flux (J) of 1.35 μg cm^-2 h^-1. The drug retention in E + D and in SC was 10.15 ± 1.36 and 1.95 ± 0.71 µg cm^-2, respectively. Retention in viable skin induced by the NE was almost two-fold higher than a compounded cream (5.04 ± 0.30 μg cm^-2). These results suggested that the developed NE is a promising alternative for 8-MOP topical therapy when compared to commercial formulations.

Recent advances of controlled drug delivery using microfluidic platforms

Conventional systematically-administered drugs distribute evenly throughout the body, get degraded and excreted rapidly while crossing many biological barriers, leaving minimum amounts of the drugs at pathological sites. Controlled drug delivery aims to deliver drugs to the target sites at desired rates and time, thus enhancing the drug efficacy, pharmacokinetics, and bioavailability while maintaining minimal side effects. Due to a number of unique advantages of the recent microfluidic lab-on-a-chip technology, microfluidic lab-on-a-chip has provided unprecedented opportunities for controlled drug delivery. Drugs can be efficiently delivered to the target sites at desired rates in a well-controlled manner by microfluidic platforms via integration, implantation, localization, automation, and precise control of various microdevice parameters. These features accordingly make reproducible, on-demand, and tunable drug delivery become feasible. On-demand self-tuning dynamic drug delivery systems have shown great potential for personalized drug delivery. This review presents an overview of recent advances in controlled drug delivery using microfluidic platforms. The review first briefly introduces microfabrication techniques of microfluidic platforms, followed by detailed descriptions of numerous microfluidic drug delivery systems that have significantly advanced the field of controlled drug delivery. Those microfluidic systems can be separated into four major categories, namely drug carrier-free micro-reservoir-based drug delivery systems, highly integrated carrier-free microfluidic lab-on-a-chip systems, drug carrier-integrated microfluidic systems, and microneedles. Microneedles can be further categorized into five different types, i.e. solid, porous, hollow, coated, and biodegradable microneedles, for controlled transdermal drug delivery. At the end, we discuss current limitations and future prospects of microfluidic platforms for controlled drug delivery.

Topical and cutaneous delivery using nanosystems

The goal of topical and cutaneous delivery is to deliver therapeutic and other substances to a desired target site in the skin at appropriate doses to achieve a safe and efficacious outcome. Normally, however, when the stratum corneum is intact and the skin barrier is uncompromised, this is limited to molecules that are relatively lipophilic, small and uncharged, thereby excluding many potentially useful therapeutic peptides, proteins, vaccines, gene fragments or drug-carrying particles. In this review we will describe how nanosystems are being increasingly exploited for topical and cutaneous delivery, particularly for these previously difficult substances. This is also being driven by the development of novel technologies, which include minimally invasive delivery systems and more precise fabrication techniques. While there is a vast array of nanosystems under development and many undergoing advanced clinical trials, relatively few have achieved full translation to clinical practice. This slow uptake may be due, in part, to the need for a rigorous demonstration of safety in these new nanotechnologies. Some of the safety aspects associated with nanosystems will be considered in this review.