Enhanced transdermal permeability of Terbinafine through novel nanoemulgel formulation; Development, in vitro and in vivo characterization

Formulation and evaluation of itraconazole-loaded nanoemulgel for efficient topical delivery to treat fungal infections

Aim: The clinical application of conventional oral dosage form of itraconazole is limited due to its poor bioavailability. The aim of the study was to develop nanoemulgel of Itraconazole for topical delivery. Method: Nanoemulsions were prepared, optimized and further incorporated into a gel and evaluated for homogeneity, pH, viscosity, spreadability, in vitro drug release and skin irritation studies. Results: Cumulative drug release from nanoemulsions was within the range of 37.24 to 47.63% at 10 h. Drug release % for all the nanoemulgel formulations at10 h was 32.39, 39.75 and 45.9% respectively. Nanoemulgel was non-irritant as demonstrated by skin irritation studies in animals. Conclusion: Itraconazole nanoemulgels were proved to be potential for effective topical delivery of drug with enhanced bioavailability.

Chitosan-based topical formulation integrated with green-synthesized silver nanoparticles utilizing Camellia sinensis leaf extracts: A promising approach for managing infected wounds

This study explores the eco-friendly biosynthesis of silver nanoparticles (AgNPs) utilizing Camellia sinensis leaf extract. We assess their antioxidant and antibacterial properties. Furthermore, we impregnated AgNPs into 2 % chitosan (CHS) gel and assessed their wound-healing potential in Escherichia coli and Staphylococcus aureus infected wounds. Optimized AgNPs demonstrated a mean particle size of 36.90 ± 1.22 nm and a PDI of 0.049 ± 0.001. Green-synthesized AgNPs exhibited enhanced free radical inhibition (IC50: 31.45 μg/mL, 34.01 μg/mL, 27.40 μg/mL) compared to leaf extract (IC50: 52.67 μg/mL, 59.64 μg/mL, 97.50 μg/mL) in DPPH, hydrogen peroxide, and nitric oxide free radical scavenging assays, respectively. The MIC/MBC values of AgNPs against E. coli and S. aureus were 5 ppm/ 7.5 ppm and 10 ppm/ 15 ppm, respectively. Furthermore, our study showed that green-synthesized AgNPs at MIC significantly reduced the biofilm production of E. coli (70.37 %) and S. aureus (67.40 %). The CHS/AgNPs gel exhibited potent wound healing activities, comparable to a commercial cream with the re-epithelialization period of 8.16 ± 0.75. Histological analysis demonstrated enhanced skin regeneration with a thicker epidermal layer, well-defined papillary dermal structure, and organized collagen fibers. In summary, these findings hold promise for addressing bacterial infections, particularly those associated with biofilms-related wound infections.

An Updated Review on Nanoemulsion: Factory for Food and Drug Delivery

BACKGROUND

A nanoemulsion is a colloidal system of small droplets dispersed in another liquid. It has attracted considerable attention due to its unique properties and various applications. Throughout this review, we provide an overview of nanoemulsions and how they can be applied to various applications such as drug delivery, food applications, and pesticide formulations.

OBJECTIVE

This updated review aims to comprehensively overview nanoemulsions and their applications as a versatile platform for drug delivery, food applications, and pesticide formulations.

METHODS

Research relevant scientific literature across various databases, including PubMed, Scopus, and Web of Science. Suitable keywords for this purpose include "nanoemulsion," "drug delivery," and "food applications." Ensure the search criteria include recent publications to ensure current knowledge is included.

RESULTS

Several benefits have been demonstrated in the delivery of drugs using nanoemulsions, including improved solubility, increased bioavailability, and controlled delivery. Nanoemulsions have improved some bioactive compounds in food applications, including vitamins and antioxidants. At the same time, pesticide formulations based on nanoemulsions have also improved solubility, shelf life, and effectiveness.

CONCLUSION

The versatility of nanoemulsions makes them ideal for drug delivery, food, and pesticide formulation applications. These products are highly soluble, bioavailable, and targeted, providing significant advantages. More research and development are required to implement nanoemulsion-based products on a commercial scale.

Microemulsions, nanoemulsions and emulgels as carriers for antifungal antibiotics

According to estimates, up to 25% of the world's population has fungal skin diseases, making them the most prevalent infectious disease. Several chemical classes of antifungal drugs are available to treat fungal infections. However, the major challenges of conventional formulations of antifungal drugs include poor pharmacokinetic profiles like solubility, low permeability, side effects and decreased efficacy. Novel drug delivery is a promising approach for overcoming pharmacokinetic limitations and increasing the effectiveness of antibiotics. In this review, we have shed light on microemulsions, nanoemulsions, and emulgels as novel drug delivery approaches for the topical delivery of antifungal antibiotics. We believe these formulations have potential translational value and could be developed for treating fungal infections in humans.

Development, stabilization, and characterization of nanoemulsion of vitamin D3-enriched canola oil

In this study, the oil-in-water nanoemulsion (NE) was prepared and loaded with vitamin D3 in food-grade (edible) canola oil and stabilized by Tween 80 and Span 80 by using a water titration technique with droplet sizes of 20 to 200 nm. A phase diagram was established for the influence of water, oil, and S-Mix concentration. The outcomes revealed that the particle size of blank canola oil nanoemulsion (NE) ranged from 60.12 to 62.27 (d.nm) and vitamin D3 NE ranged from 93.92 to 185.5 (d.nm). Droplet size and polydispersity index (PDI) of both blank and vitamin D3-loaded NE results were less than 1, and zeta potential results for blank and vitamin D3 loaded NE ranged from -9.71 to -15.32 mV and -7.29 to -13.56 mV, respectively. Furthermore, the pH and electrical conductivity of blank NE were 6.0 to 6.2 and 20 to 100 (μs/cm), respectively, whereas vitamin D3-loaded NE results were 6.0 to 6.2 and 30 to 100 (μs/cm), respectively. The viscosity results of blank NE ranged from 0.544 to 0.789 (mPa.s), while that of vitamin D3-loaded NE ranged from 0.613 to 0.793 (mPa.s). In this study, the long-term stability (3 months) of canola oil NE containing vitamin D3 at room temperature (25 C) and high temperature (40 C) was observed.

Crisaborole loaded nanoemulgel for the mitigation of atopic dermatitis in mice model

OBJECTIVE

The present work aims to formulate nanoemulgel of crisaborole (CB) and evaluate its effectiveness against 2,4-Di-nitrochlorobenzene induced (DNCB) atopic dermatitis (AD) in mice.

SIGNIFICANCE

AD is a chronic inflammation of the skin affecting the quality of life. CB is a topical PDE4 inhibitor marketed as a 2% ointment. It, however, possesses poor aqueous solubility. An o/w nanoemulsion shall exhibit an enhanced therapeutic effect owing to the increased solubility of CB and an augmented skin penetration. The addition of a gelling agent to form a nanoemulgel further provides ease of application to the patients.

METHODS

Nanoemulsion was prepared by aqueous titration method using caproyl PGMC, cremophore EL and propylene glycol as the oil, surfactant, and cosurfactant respectively. The formulations were characterized by their size, zeta potential and polydispersity index (PDI). 1% Carbopol 934 was used as the gelling agent to formulate nanoemulgel comprising of optimized nanoemulsion (NE 9). Ex vivo skin permeation of the CB nanoemulgel was compared with the CB ointment. Its therapeutic effect was evaluated in Balb/c mice.

RESULTS

NE 9 comprised of 7.49% oil, 37.45% Smix (1:3) and water 55.06%. Its particle size, PDI and zeta potential were 15.45 ± 5.265 nm, 0.098 and -17.9 ± 8.00 mV respectively. The nanoemulgel exhibited a 3-fold higher permeation flux as compared to the ointment. In vivo studies demonstrated that the nanoemulgel provided better therapeutic effect than the ointment.

CONCLUSION

We can thereby conclude that nanoemulgel formulation can be a successful drug delivery strategy for enhancing the therapeutic effect of CB.

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.

Design and fabrication of Sesamol-loaded transfersomal gel for wound healing: physicochemical characterization and in-vivo evaluation

OBJECTIVE

In the present study, an attempt has been made to develop SL-loaded transfersomal gel for the effective treatment of delayed wound healing.

SIGNIFICANCE

The wound healing process consists of a complex series of biochemical events and changes in cellular activity that restore the integrity of the skin and the subcutaneous tissue. Sesamol (SL), which is a natural phenolic compound, is known for its antioxidant properties, anti-inflammatory properties, and wound-healing abilities.

METHODS

A thin-film hydration method was used to prepare SL-loaded transfersomes. Different formulations containing Tween-80 and Span-80 as edge activators were prepared and optimized. Various characteristics of vesicles were assessed, such as size, shape, loading efficiency, deformability, and in vitro skin penetration. The optimized formulation was then incorporated into 1% carbopol 940 gel. An in vivo wound healing potential of the selected formulation was assessed by an excision wound model.

RESULTS

The SL-loaded transfersomal gel displayed improved skin penetration and better skin deposition. Wound healing studies showed that the highest wound contraction was observed with SL-loaded transfersomes. Following 21 days of application of the transfersomal gel, a marked improvement in skin histological architecture was found.

CONCLUSION

The study findings suggest that transfersomal gel has great potential as a therapeutic option in wound healing.

Nanoemulgel: A Novel Nano Carrier as a Tool for Topical Drug Delivery

Nano-emulgel is an emerging drug delivery system intended to enhance the therapeutic profile of lipophilic drugs. Lipophilic formulations have a variety of limitations, which includes poor solubility, unpredictable absorption, and low oral bioavailability. Nano-emulgel, an amalgamated preparation of different systems aims to deal with these limitations. The novel system prepared by the incorporation of nano-emulsion into gel improves stability and enables drug delivery for both immediate and controlled release. The focus on nano-emulgel has also increased due to its ability to achieve targeted delivery, ease of application, absence of gastrointestinal degradation or the first pass metabolism, and safety profile. This review focuses on the formulation components of nano-emulgel for topical drug delivery, pharmacokinetics and safety profiles.

Therapeutic Textiles Functionalized with Keratin-Based Particles Encapsulating Terbinafine for the Treatment of Onychomycosis

Onychomycosis is the most common nail fungal infection worldwide. There are several therapy options available for onychomycosis, such as oral antifungals, topicals, and physical treatments. Terbinafine is in the frontline for the treatment of onychomycosis; however, several adverse effects are associated to its oral administration. In this work, innovative keratin-based carriers encapsulating terbinafine were designed to overcome the drawbacks related to the use this drug. Therapeutic textiles functionalized with keratin-based particles (100% keratin; 80% keratin/20% keratin-PEG) encapsulating terbinafine were developed. The controlled release of terbinafine from the functionalized textiles was evaluated against different mimetic biologic solutions (PBS buffer-pH = 7.4, micellar solution and acidic sweat solution-pH = 4.3). The modification of keratin with polyethylene glycol (PEG) moieties favored the release of terbinafine at the end of 48 h for all the solution conditions. When the activity of functionalized textiles was tested against Trichophyton rubrum, a differentiated inhibition was observed. Textiles functionalized with 80% keratin/20% keratin-PEG encapsulating terbinafine showed a 2-fold inhibition halo compared with the textiles containing 100% keratin-encapsulating terbinafine. No activity was observed for the textiles functionalized with keratin-based particles without terbinafine. The systems herein developed revealed therapeutic potential towards nail fungal infections, taking advantage of keratin-based particles affinity to keratin structures and of the keratinase activity of T. rubrum.

Investigation of a Minocycline-Loaded Nanoemulgel for the Treatment of Acne Rosacea

In the present investigation, a nanoemulgel of minocycline was formulated and optimized for an improved drug delivery and longer retention time in the targeted area. Combining eucalyptus oil, Tween 20, and Transcutol HP, different o/w nanoemulsions were formulated by the oil phase titration method and optimized by pseudo-ternary phase diagrams. The morphology, droplet size, viscosity, and refractive index of the thermodynamically stable nanoemulsion were determined. Furthermore, optimized nanoemulsion was suspended in 1.0% w/v of Carbopol 940 gel to formulate the nanoemulgel, and for this, pH, viscosity, and spreadability were determined and texture analysis was performed. To compare the extent of drug penetration between nanoemulsion and nanoemulgel, ex vivo skin permeation studies were conducted with Franz diffusion cell using rat skin as the permeation membrane, and the nanoemulgel exhibited sustained-release behavior. It can be concluded that the suggested minocycline-containing naoemulgel is expected to treat acne rosacea more effectively.

Fabrication and Characterizations of Pharmaceutical Emulgel Co-Loaded with Naproxen-Eugenol for Improved Analgesic and Anti-Inflammatory Effects

The aim of this study was to fabricate and characterize a pharmaceutical emulgel co-loaded with naproxen/eugenol for transdermal delivery to improve the analgesic and anti-inflammatory effects and to eliminate GIT adverse reactions. Emulgel was prepared using a slow emulsification method and evaluated for physical appearance, thermodynamic stability, viscosity, pH, spreadability, extrudability, in-vitro drug release, drug content, ex-vivo permeation, drug retention studies and in-vivo studies. The emulgel exhibited good physical attributes, being thermodynamically stable with no phase separation, having excellent homogeneity, and pH 5.5 to 6.5. Slight changes in viscosity, spreadability and extrudability with respect to high temperature were observed (p > 0.05). The drug content was 96.69 ± 1.18% and 97.24 ± 1.27% for naproxen and eugenol, respectively. The maximum release of naproxen after 12 h was 85.14 ± 1.11%, whereas eugenol was 86.67 ± 1.23% from emulgel following anomalous non-Fickian mechanism. The maximum % permeation of naproxen across skin was 78.5 ± 1.30, whereas maximum % permeation of eugenol was 83.7 ± 1.33 after 12 h. The skin retention of eugenol and naproxen was 8.52 ± 0.22% and 6.98 ± 0.24%, respectively. The optimized emulgel inhibited the carrageenan induced paw edema. The pain reaction times of optimized emulgel and standard marketed product (Voltral®) were 11.16 ± 0.17 and 10.36 ± 0.47, respectively, with no statistically significant difference (p > 0.05). This study concluded that transdermal delivery of naproxen-eugenol emulgel synergized the anti-inflammatory and analgesic effects of naproxen and eugenol.

Silk peptide-hyaluronic acid based nanogels for the enhancement of the topical administration of curcumin

The present study focused on the development of Cur-loaded SOHA nanogels (Cur-SHNGs) to enhance the topical administration of Cur. The physiochemical properties of Cur-SHNGs were characterized. Results showed that the morphology of the Cur-SHNGs was spherical, the average size was 171.37 nm with a zeta potential of −13.23 mV. Skin permeation experiments were carried out using the diffusion cell systems. It was found that the skin retention of Cur-SHNGs was significantly improved since it showed the best retention value (0.66 ± 0.17 μg/cm²). In addition, the hematoxylin and eosin staining showed that the Cur-SHNGs improved transdermal drug delivery by altering the skin microstructure. Fluorescence imaging indicated that Cur-SHNGs could effectively deliver the drug to the deeper layers of the skin. Additionally, Cur-SHNGs showed significant analgesic and anti-inflammatory activity with no skin irritation. Taken together, Cur-SHNGs could be effectively used for the topical delivery of therapeutic drugs.

Emerging trends and promises of nanoemulsions in therapeutics of infectious diseases

Infectious diseases are prevalent and have contributed to high morbidity rates by creating havoc like the COVID-19, 1918 influenza and Black Death (the plague) pandemics. Antimicrobial resistance, adverse effects, the emergence of co-infections and the high cost of antimicrobial therapies are major threats to the health of people worldwide while impacting overall healthcare and socioeconomic development. One of the most common ways to address this issue lies in improving existing antimicrobial drug-delivery systems. Nanoemulsions and their modified forms have been successfully employed for the delivery of antimicrobials to treat infectious diseases. In this article, the authors comprehensively reviewed how nanoemulsion-based formulation systems are shifting the paradigm for therapeutics and diagnosis of infectious diseases.

Ex vivo permeation parameters and skin deposition of melatonin-loaded microemulsion for treatment of alopecia

Background

Melatonin (MEL) is a powerful antioxidant molecule with anti-androgenic property. A microemulsion (ME) system loaded with MEL was designed for treatment of androgenic alopecia. Pseudo-ternary phase diagram was constructed, and ME formulae were developed using coconut oil, Tween 80 and PEG 400. In the present study, MEL ME was characterized and evaluated for droplet size, polydispersity index, zeta potential, morphology using TEM imaging. MEL ex vivo permeation study through rat skin followed by tape stripping for stratum corneum (SC) was performed for different ME formulae, to determine skin permeation parameters and detect SC-MEL deposition.

Results

Spherical and uniform particles of MEL-loaded microemulsion were formulated with high stability. In ex vivo permeation study, MEL ME exhibited low steady-state skin flux along with pronounced SC deposition which prevailed a controlled release manner.

Conclusion

The results suggested that MEL ME could be a promising candidate for further permeation and in vivo studies for androgenic alopecia treatment.

Development, Characterization and Optimization of the Anti-Inflammatory Influence of Meloxicam Loaded into a Eucalyptus Oil-Based Nanoemulgel

The purpose of the present study was to explore the influence of a certain natural essential oil, namely eucalyptus oil, as an anti-inflammatory agent in addition to its prospective role in enhancing the action of meloxicam in reducing inflammation. As far as we know, this has been the first integration of meloxicam and eucalyptus essential oil into a nanoemulgel formulation intended for topical use. Primarily, eucalyptus oil was utilized in developing a nanoemulsion formulation incorporating meloxicam. A 22 factorial design was constructed using two independent variables (oil concentration and surfactant concentration) with two responses (particle size and % of in vitro release). One optimized formula was selected depending on the desirability function and subjected to a stability study. The optimized nanoemulsion was mixed with HPMC as a gelling agent to produce a meloxicam-loaded nanoemulgel, which was examined for its properties, stability, in vitro release and ex vivo permeation. Eventually, the anti-inflammatory activity was evaluated and compared with a placebo and corresponding gel formulation. The developed nanoemulgel revealed acceptable physical characteristics to be applied topically. Studying of the in vitro release was conducted successfully for 6 h. The ex vivo permeation from the nanoemulgel formulations was prompted, showing an appropriate value of the steady-state transdermal flux (SSTF). As a final point, the anti-inflammatory activity of the developed nanoemulgel revealed a valued anti-inflammatory influence. Additionally, the concurrence of eucalyptus essential oil and meloxicam was assured, and their potential in combating and lowering inflammation was supported.

The ascension of nanosponges as a drug delivery carrier: preparation, characterization, and applications

Nanosponges are nanosized drug carriers with a three-dimensional structure created by crosslinking polymers. They have the advantage of being able to hold a wide range of drugs of various sizes. Nanosponges come in a variety of shapes and sizes. They are distinguished by the research method used, the type of polymer used, and the type of drug they may contain. Nanosponges are superior to other delivery systems because they can provide a controlled drug release pattern with targeted drug delivery. The period of action, as well as the drug's residence time, may be regulated. Since it is made of biodegradable materials, it has a low toxicity and is safe to use. The efficiency of drug encapsulation is determined by the size of the drug molecule and the amount of void space available. Cancer, enzyme and biocatalyst carrier, oxygen delivery, solubility enhancement, enzyme immobilization, and poison absorbent are some of the applications for nanosponges. The method of preparation, characterization, factors affecting nanosponge development, drug loading and release mechanism, recent developments in this area, and patents filed in the area of nanosponges are all highlighted in this study. Graphical abstract.

Musa acuminata nanoemulgel: formulation, in vitro kinetics and antimicrobial studies

The study was intended to formulate nanoemulgel from the leaf extract of Musa acuminata. Ethanol and chloroform were used as solvents in the ratio of 1:8 (%w/v). DL-alpha-tocopherol, characterised by gas chromatography mass spectrometry, was identified to be the major component with potential biological activities. Based on a pseudo-ternary plot, the 1:1 S mix (surfactant:co-surfactant) ratio was optimised as it posed maximum regions of emulsion. The prepared nanoemulgel was evaluated for physical appearance, pH, spreadability and swelling index. The appearance was pale yellowish-white, translucent within a pH range of 5–5.8. Antimicrobial studies were performed against dandruff-causing microbes (Staphylococcus epidermidis and Malassezia furfur). In vitro studies were carried out for optimised formulations of EG2, EG4, CG2 and CG3. The drug release of 94.28% after 12 h with the Higuchi plot of R 2 value as 0.99 was observed for EG2. The kinetically optimised formulation, EG2, was found to have a good spreadability of 12.2 (g cm)/s and a swelling index of 64%.

Nanoemulsion-based dosage forms for the transdermal drug delivery applications: A review of recent advances

INTRODUCTION

Nanoemulsion-based drug delivery approaches have witnessed massive acceptance over the years and acquired a significant foothold owing to their tremendous benefits over the others. It has widely been used for transdermal delivery of hydrophobic and hydrophilic drugs with solubility, lipophilicity, and bioavailability issues.

AREAS COVERED

The review highlights the recent advancements and applications of transdermal nanoemulsions. Their utilities and characteristics, clinical pertinence showcasing intellectual properties and advancements, potential in treating disorders accompanying liquid, semisolid, and solid dosage forms, the ability to modulate a drug's physicochemical properties, and regulatory status are thoroughly summarized.

EXPERT OPINION

Despite tremendous therapeutic utilities and extensive investigations, this field of transdermal nanoemulsion-based technologies yet tackles several challenges such as optimum use of surfactant mixtures, economic burden due to high energy consumption during production, lack of concrete regulatory requirement, etc. Provided with the concrete guidelines on the safe use of surfactants, stability, use of scalable and economical methods, and the use of NE as a transdermal system would solve the purpose best as nanoemulsion shows remarkable improvement in drug release profiles and bioavailability of many drugs. Nevertheless, a better understanding of nanoemulsion technology holds a promising outlook and would land more opportunities and better delivery outcomes.

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.

Development, Optimization, and Evaluation of Luliconazole Nanoemulgel for the Treatment of Fungal Infection

The present study aimed to optimize luliconazole nanoemulsion using Box–Behnken statistical design, which was further incorporated into the polymeric gel of Carbopol 934. The formulation was characterized for its size, entrapment efficiency, ex vivo permeation, and mechanism of release. The size of the dispersed globules of the optimized drug-loaded nanoemulsion was found to be 17 ± 3.67 nm with a polydispersity index (PDI) less than 0.5. Although the surface charge was recorded at –9.53 ± 0.251, the stability was maintained by the polymeric matrix that prevented aggregation and coalescence of the dispersed globules. The luliconazole-nanoemulgel (LUL-NEG) was characterized for drug content analysis, viscosity, pH, and refractive index, where the results were found to be 99.06 ± 0.59%, 9.26 ± 0.08 Pa.s, 5.65 ± 0.17, and 1.31 ± 0.08, respectively. The permeation across the rat skin was found to be significantly higher with LUL-NEG when compared with LUL gel. Furthermore, the skin irritation test performed in experimental animals revealed that the blank NEG, as well as the LUL-NEG, did not produce any signs of erythema following 48 h exposure. In addition, the histopathological findings of the experimental skins reported no abnormal signs at the formulation application site. Finally, the NEG formulation was found to create a statistically significant zone of inhibition ( $P$  < 0.05) when compared to all other test groups. Overall, it could be summarized that the nanoemulgel approach of delivering luliconazole across the skin to treat skin fungal infections could be a promising strategy.

Chitosan (Poly-(D) glucosamine) based solid lipid nanoparticles of dexibuprofen for topical delivery: Formulation development and characterizations

Chitosan a poly-(D) glucosamine is a polysaccharide made by treating shrimp and other crustacean shells with the alkali sodium hydroxide. It is a hydrophilic polymer that helps to retain the drug inside the solid lipid nanoparticles (SLN’s) and prolongs the release of drug from the carrier system. The purpose of the study was to formulate Chitosan decorated SLN’s for the topical delivery of dexibuprofen by hot pressure homogenization technique. Blank SLN’s, drug loaded SLN’s and Chitosan decorated SLN’s were prepared. Particle size, zeta potential and PDI were determined. FTIR study was conducted to evaluate the compatibility of excipients with the active drug. Surface morphology of SLN’s was determined by field emission scanning electron microscope. Drug content and entrapment efficiency of SLN’s were determined using indirect method. In vitro release and ex vivo permeation study of SLN’s were carried out using Franz diffusion cell. The droplet size fell into the nano range i.e. 132±7 to 424±2 nm which is effective for topical drug delivery system. The PDI of formulations range from 0.21 to 0.42 which depicts the homogeneity of all the SLN’s formulations. Vibrational analysis indicates that there is no interaction between active drug and excipient used in the formulation. The surface morphology revealed the spherical shape of Chitosan decorated SLN’s. The in vitro release of formulations showed 79.91±1.07 to 89.94±1.8 % drug release. The drug permeation study showed high permeation of drug into the skin. The percent drug permeation ranges from 64.15±0.93 to 71.80±0.88% indicating good permeation of drug across the skin. Overall, SLN’s are an effective carrier for topical delivery of dexibuprofen and thus bypasses side effects associated with oral delivery.

Glimepiride-Loaded Nanoemulgel; Development, In Vitro Characterization, Ex Vivo Permeation and In Vivo Antidiabetic Evaluation

Glimepiride (GMP), an oral hypoglycemic agent is extensively employed in the treatment of type 2 diabetes. Transdermal delivery of GMP has been widely investigated as a promising alternative to an oral approach but the delivery of GMP is hindered owing to its low solubility and permeation. The present study was designed to formulate topical nanoemulgel GMP system and previously reported solubility enhanced glimepiride (GMP/βCD/GEL-44/16) in combination with anti-diabetic oil to enhance the hypoglycemic effect. Nanoemulsions were developed using clove oil, Tween-80, and PEG-400 and were gelled using xanthan gum (3%, w/w) to achieve the final nanoemulgel formulations. All of the formulations were evaluated in terms of particle size, zeta potential, pH, conductivity, viscosity, and in vitro skin permeation studies. In vivo hypoglycemic activity of the optimized nanoemulgel formulations was evaluated using a streptozocin-induced diabetes model. It was found that a synergistic combination of GMP with clove oil improved the overall drug permeation across the skin membrane and the hypoglycemic activity of GMP. The results showed that GMP/βCD/GEL-44/16-loaded nanoemulgel enhanced the in vitro skin permeation and improved the hypoglycemic activity in comparison with pure and marketed GMP. It is suggested that topical nano emulsion-based GMP gel and GMP/βCD/GEL-44/16 could be an effective alternative for oral therapy in the treatment of diabetes.

Preparation, characterization and evaluation of anti-inflammatory and anti-nociceptive effects of brucine-loaded nanoemulgel

Brucine (BRU) is a natural product derived from nux-vomica seeds. It is commonly used as an anti-inflammatory and anti-nociceptive drug to relieve arthritis and traumatic pain. Nevertheless, its use is significantly limited by its low aqueous solubility, as well as the gastrointestinal problems and systemic toxicity that may occur following oral administration. The goal of this study, therefore, was to formulate and evaluate a nanoemulgel formulation of BRU for enhanced topical anti-inflammatory and anti-nociceptive activities. Different formulations were developed (BRU gel, emulgel and nanoemulgel) using 1% w/w NaCMC as a gelling agent. The formulated preparations were assessed for their physical appearance, spreadability, viscosity, particle size, in vitro drug release and ex vivo permeation studies. In addition, the carrageenan-induced rat hind paw edema method was adopted to scrutinize the anti-inflammatory activity, while the hot plate method and acetic acid-induced writhing test were used to assess the anti-nociceptive activity of different formulations in male BALB/c mice. The formulated BRU-loaded preparations showed good physical characteristics. Cumulative drug release from BRU-loaded nanoemulgel was remarkably higher than that of the other formulations. Ex vivo drug permeation of the nanoemulgel formulation across rat skin showed enhanced drug permeation and higher transdermal flux as compared to BRU-loaded gel or emulgel. Most importantly, the carrageenan-induced rat hind paw edema model verified the efficient anti-inflammatory potential of BRU-loaded nanoemulgel. In addition, BRU-loaded nanoemulgel exhibited significant protective effects against thermal stimulation in the hot plate test and remarkably inhibited acetic acid-induced abdominal writhing in mice. Furthermore, a skin irritation test indicated that BRU-loaded nanoemulgel elicited neither edema nor erythema upon application to rat skin. Collectively, our results suggest that myrrh oil-based nanoemulgel might represent a promising delivery vehicle for potentiating the anti-inflammatory and anti-nociceptive actions of brucine.

Antimicrobial and wound healing properties of cotton fabrics functionalized with oil-in-water emulsions containing Pinus brutia bark extract and Pycnogenol® for biomedical applications

Topical formulations containing 1-2% of Pinus brutia bark extract and Pycnogenol® have been prepared to investigate the effect of flavonoids on the stability of O/W emulsions, which were subjected to physicochemical and thermal stability tests. The formulations have been applied to cotton fabrics to evaluate antimicrobial properties against Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus brasiliensis. Furthermore, prepared cotton fabrics have been tested on keratinocytes seeded in cell culture inserts for wound healing. Results of freeze thaw cycle test indicated enhanced thermo-stability with no major changes in pH and viscosity, likewise the results of centrifugation assay. However, the addition of Pycnogenol® has tremendously decreased the viscosity of the topical formulation (10,900 cp.). In terms of antimicrobial activity, 2% P. brutia treated cotton fabrics decreased the proliferation of Aspergillus brasiliensis 78.8%, which were more effective than that of Pycnogenol® formulation (62.9%). As for wound healing, 2% P. brutia treated cotton fabrics increased HaCaT keratinocyte cell proliferation and accelerated the cell-free gap closure compared to Pycnogenol® and untreated control groups. The obtained results indicate the utilization of pine bark for developing an eco-friendly natural antifungal finish for medical textiles.

Nanoemulgel, an Innovative Carrier for Diflunisal Topical Delivery with Profound Anti-Inflammatory Effect: in vitro and in vivo Evaluation

Purpose

Rheumatoid arthritis is an autoimmune disorder that directly affects joints. However, other body organs including heart, eyes, skin, blood vessels and lungs may also be affected. The purpose of this study was to design and evaluate a nanoemulgel formulation of diflunisal (DIF) and solubility enhanced diflunisal (DIF-IC) for enhanced topical anti-inflammatory activity.

Methodology

Nanoemulsion formulations of both DIF and DIF-IC were prepared and incorporated in three different gelling agents, namely carboxymethylcellulose sodium (CMC-Na), sodium alginate (Na-ALG) and xanthan gum (XG). All the formulations were evaluated in term of particle size, pH, conductivity, viscosity, zeta potential and in vitro drug release. The formulation 2 (NE2) of both DIF and DIF-IC which expressed optimum release and satisfactory physicochemical properties was incorporated with gelling agents to produce final nanoemulgel formulations. The optimized nanoemulgel formulation was subjected to three different in vivo anti-inflammatory models including carrageenan-induced paw edema model, histamine-induced paw edema model and formalin-induced paw edema model.

Results

DIF-IC-loaded nanoemulgel formulations yielded significantly enhanced in vitro skin permeation than DIF-loaded nanoemulgel. The nanoemulgel formulation of DIF-IC formulated with XG produced improved in vivo anti-inflammatory activity.

Conclusion

It was recommended that DIF-IC-based nanoemulgel formulation prepared with XG could be a better option for effective topical treatment of inflammatory conditions.

Physicochemical Characterization of Finasteride Nanosystem for Enhanced Topical Delivery

INTRODUCTION

The current work aimed to formulate a novel chitosan-based finasteride nanosystem (FNS-NS) for skin delivery to optimize the drug availability in skin for a longer time and enhance ex vivo performance of finasteride against androgenic alopecia.

METHODS

Both undecorated and chitosan decorated FNS-NSs were synthesized by a high energy emulsification technique. All the prepared nanosystems were further subjected to physicochemical characterizations like pH, viscosity, encapsulation efficiency, surface morphology and in vitro drug release behavior. The influence of the nanosystem on the drug permeation and retention in rat skin was examined using Franz diffusion cell apparatus.

RESULTS

The droplet size of developed nanosystems ranged from 41 to 864 nm with a low polydispersity index. The zeta potential of the nanosystems was between -10 mV and +56 mV. This chitosan decorated nanosystem exhibited controlled drug release, ie about 78-97% in 24 h. Among all the nanosystems, our chitosan decorated formulation (F5) had low drug permeation (16.35 µg/cm2) and higher drug retention (10.81 µg/cm2).

CONCLUSION

The abovementioned results demonstrate satisfactory in vitro drug release, skin retention profiles and ex vivo performance with chitosan decorated FNS-NS (F5). This optimized formulation could increase drug availability in skin and could become a promising carrier for topical delivery to treat androgenic alopecia.

Enhancement of Curcumin Anti-Inflammatory Effect via Formulation into Myrrh Oil-Based Nanoemulgel

Background: Curcumin (Cur) possesses a variety of beneficial pharmacological properties including antioxidant, antimicrobial, anti-cancer and anti-inflammatory activities. Nevertheless, the low aqueous solubility and subsequent poor bioavailability greatly limits its effectiveness. Besides, the role of myrrh oil as an essential oil in treating inflammatory disorders has been recently demonstrated. The objective of the current investigation is to enhance Cur efficacy via developing Cur nanoemulgel, which helps to improve its solubility and permeability, for transdermal delivery. Methods: The formulated preparations (Cur gel, emulgel and nanoemulgel) were evaluated for their physical appearance, spreadability, viscosity, particle size, in vitro release and ex vivo drug permeation studies. The in vivo anti-inflammatory activity was estimated using the carrageenan-induced rat hind paw edema method. Results: The formulated Cur-loaded preparations exhibited good physical characteristics that were in the acceptable range of transdermal preparations. The release of Cur from gel, emulgel and nanoemulgel after 12 h was 72.17 ± 3.76, 51.93 ± 3.81 and 62.0 ± 3.9%, respectively. Skin permeation of Cur was significantly (p < 0.05) improved when formulated into nanoemulgel since it showed the best steady state transdermal flux (SSTF) value (108.6 ± 3.8 µg/cm²·h) with the highest enhancement ratio (ER) (7.1 ± 0.2). In vivo anti-inflammatory studies proved that Cur-loaded nanoemulgel displayed the lowest percent of swelling (26.6% after 12 h). Conclusions: The obtained data confirmed the potential of the nanoemulgel dosage form and established the synergism of myrrh oil and Cur as an advanced anti-inflammatory drug.

Apremilast Microemulsion as Topical Therapy for Local Inflammation: Design, Characterization and Efficacy Evaluation

Apremilast (APR) is a selective phosphodiesterase 4 inhibitor administered orally in the treatment of moderate-to-severe plaque psoriasis and active psoriatic arthritis. The low solubility and permeability of this drug hinder its dermal administration. The purpose of this study was to design and characterize an apremilast-loaded microemulsion (APR-ME) as topical therapy for local skin inflammation. Its composition was determined using pseudo-ternary diagrams. Physical, chemical and biopharmaceutical characterization were performed. Stability of this formulation was studied for 90 days. Tolerability of APR-ME was evaluated in healthy volunteers while its anti-inflammatory potential was studied using in vitro and in vivo models. A homogeneous formulation with Newtonian behavior and droplets of nanometric size and spherical shape was obtained. APR-ME released the incorporated drug following a first-order kinetic and facilitated drug retention into the skin, ensuring a local effect. Anti-inflammatory potential was observed for its ability to decrease the production of IL-6 and IL-8 in the in vitro model. This effect was confirmed in the in vivo model histologically by reduction in infiltration of inflammatory cells and immunologically by decrease of inflammatory cytokines IL-8, IL-17A and TNFα. Consequently, these results suggest that this formulation could be used as an attractive topical treatment for skin inflammation.

Nanosystems against candidiasis: a review of studies performed over the last two decades

The crescent number of cases of candidiasis and the increase in the number of infections developed by non-albicans species and by multi-resistant strains has taken the attention of the scientific community, which has been searching for new therapeutic alternatives. Among the alternatives found the use of nanosystems for delivery of drugs already commercialized and new biomolecules have grown, in order to increase stability, solubility, optimize efficiency and reduce adverse effects. In view of the growing number of studies involving technological alternatives for the treatment of candidiasis, the present review came with the intention of gathering studies from the last two decades that used nanotechnology for the treatment of candidiasis, as well as analysing them critically and pointing out the future perspectives for their application with this purpose. Different studies were considered for the development of this review, addressing nanosystems such as metallic nanoparticles, mesoporous silica nanoparticles, polymeric nanoparticles, liposomes, nanoemulsion, microemulsion, solid lipid nanoparticle, nanostructured lipid carrier, lipidic nanocapsules and liquid crystals; and different clinical presentations of candidiasis. As a general overview, nanotechnology has proven to be an important ally for the treatment against the diversity of candidiasis found in the clinic, whether in increasing the effectiveness of commercialized drugs and reducing their adverse effects, as well as allowing exploring more effectively properties therapeutics of new biomolecules.

Co-Delivery of Imiquimod and Curcumin by Nanoemugel for Improved Topical Delivery and Reduced Psoriasis-Like Skin Lesions

The current investigation aimed to improve the topical efficacy of imiquimod in combination with curcumin using the nanoemulsion-based delivery system through a combinatorial approach. Co-delivery of curcumin acts as an adjuvant therapeutic and to minimize the adverse skin reactions that are frequently associated with the topical therapy of imiquimod for the treatment of cutaneous infections and basal cell carcinomas. The low-energy emulsification method was used for the nano-encapsulation of imiquimod and curcumin in the nanodroplet oil phase, which was stabilized using Tween 20 in an aqueous dispersion system. The weak base property of imiquimod helped to increase its solubility in oleic acid compared with ethyl oleate, which indicates that fatty acids should be preferred as the oil phase for the design of imiquimod-loaded topical nanoemulsion compared with fatty acid esters. The phase diagram method was used to optimize the percentage composition of the nanoemulsion formulation. The mean droplet size of the optimized nanoemulsion was 76.93 nm, with a polydispersity index (PdI) value of 0.121 and zeta potential value of −20.5 mV. The optimized imiquimod-loaded nanoemulsion was uniformly dispersed in carbopol 934 hydrogel to develop into a nanoemulgel delivery system. The imiquimod nanoemulgel exhibited significant improvement (p < 0.05) in skin permeability and deposition profile after topical application. The in vivo effectiveness of the combination of imiquimod and curcumin nanoemulgel was compared to the imiquimod nanoemulgel and imiquimod gel formulation through topical application for ten days in BALB/c mice. The combination of curcumin with imiquimod in the nanoemulgel system prevented the appearance of psoriasis-like symptoms compared with the imiquimod nanoemulgel and imiquimod gel formulation entirely. Further, the imiquimod nanoemulgel as a mono-preparation slowed and reduced the psoriasis-like skin reaction when compared with the conventional imiquimod gel, and that was contributed to by the control release property of the nano-encapsulation approach.

Development of nanoemulsion gel drug delivery systems of cetirizine; factorial optimisation of composition, in vitro evaluation and clinical study

Aim: This work aimed to develop topical nanoemulsion gels of cetirizine, a second-generation antihistamine, to avoid its oral intake drawbacks and enhance skin permeation.Methods: Cetirizine nanoemulsions were formulated and characterised for their particle size, polydispersity index, zeta potential, drug release and drug permeation through rat skin. The optimised formulation, obtained using 2³ full factorial design, was incorporated in carbopol and chitosan gels and evaluated clinically for urticaria treatment.Results: The optimised formulation had particle size of 32.015 ± 1.87 nm, polydispersity index of 0.29 ± 0.04, zeta potential of -19.31 ± 0.43 mV, cetirizine percent released of 98.50 ± 1.23% and permeability coefficient of 7.65 cm.h^-1. Cetirizine nanoemulsion gels were more effective than their control gels in urticaria treatment with significant decrease in the degree of wheals and itching and higher recovery percent.Conclusion: Cetirizine nanoemulsion topical gels are expected to be a rational and effective tool for avoiding cetirizine oral side effects and targeting the affected skin.

Nano-emulgel: Emerging as a Smarter Topical Lipidic Emulsion-based Nanocarrier for Skin Healthcare Applications

BACKGROUND

In recent decades, enormous efforts for different drug discovery processes have led to a number of drug molecules available today to overcome different challenges of the health care system. Unfortunately, more than half of these drugs are listed in either BCS (biopharmaceutical classification system) class II/ IV or both are eliminated from the development pipeline due to their limited clinical use. A nanotechnological approach bears much hope and lipoidal fabrication is found to be suitable for the delivery of such drugs. Nanoemulsion based gel i.e. nanoemulgel out of different nanolipoidal formulations has been found to be a suitable approach to successful drug delivery through topical routes. In past few years many herbal and synthetic active pharmaceutical ingredients (APIs) has been patented as nano sized emulsified gel for various therapeutic activities.

METHODS

Nanoemulgel is basically an emulsion-based topical gel formulation, where nanosized emulsion globules can be prepared with the help of high energy or low energy methods and further converted into nanoemulgel by adding a suitable gelling agent. Nanoemulgel fabrication enlists various kinds of polymeric materials, surfactants and fatty substances of natural, synthetic and semi-synthetic nature with a globule size range from 5 to 500 nm.

RESULTS

Nanoemulgel can be applicable to various acute and chronic diseases through topical routes.

CONCLUSION

Nanoemulgel preparations of many recently approved drugs are being used successfully in different areas of health care and have re-defined the significance of topical route of delivery as compared to other routes. However, along with various improvements in the current state of the delivery system, the safety factor needs to be taken into account by toxicological studies of the materials used in such formulations.

Novel Clove Essential Oil Nanoemulgel Tailored by Taguchi's Model and Scaffold-Based Nanofibers: Phytopharmaceuticals with Promising Potential as Cyclooxygenase-2 Inhibitors in External Inflammation

PURPOSE

Clove essential oil is a phytochemical possessing a vast array of biological activities. Nevertheless, fabricating nano topical delivery systems targeted to augment the anti-inflammatory activity of the oil has not been investigated so far. Accordingly, in this study, controlled release nanoparticulate systems, namely nanoemulgel and nanofibers (NFs), of the oil were developed to achieve such goal.

METHODS

The nanoemulsion was incorporated in the hydrogel matrix of mixed biopolymers - chitosan, guar gum and gum acacia - to formulate nanoemulsion-based nanoemulgel. Taguchi's model was adopted to evaluate the effect of independently controlled parameters, namely, the concentration of chitosan (X1), guar gum (X2), and gum acacia (X3) on different dependently measured parameters. Additionally, the nanoemulsion-based NFs were prepared by the electrospinning technique using polyvinyl alcohol (PVA) polymer. Extensive in vitro, ex vivo and in vivo evaluations of the aforementioned formulae were conducted.

RESULTS

Both Fourier transform-infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) established the complete dispersion of the nanoemulsion in the polymeric matrices of the prepared nanoemulgel and NFs. The ex vivo skin permeation data of clove essential oil from the prepared formulations showed that NFs can sustain its penetration through the skin comparably with nanoemulgel. Topical treatment with NFs (once application) and nanoemulgel (twice application) evoked a marvelous in vivo anti-inflammatory activity against croton oil-induced mouse skin inflammation model when compared with pure clove essential oil along with relatively higher efficacy of medicated NFs than that of medicated nanoemulgel. Such prominent anti-inflammatory activity was affirmed by histopathological and immunohistochemical examinations.

CONCLUSION

These results indicated that nanoemulsion-based nanoemulgel and nanoemulsion-based NFs could be introduced to the phytomedicine field as promising topical delivery systems for effective treatment of inflammatory diseases instead of nonsteroidal anti-inflammatory drugs that possess adverse effects.

Development and optimization of nanoemulsion based gel for enhanced transdermal delivery of nitrendipine using box-behnken statistical design

Objective: The purpose of present research was to develop and statistically optimize nitrendipine nanoemulsion gel for transdermal delivery using box-behnken statistical design.Method: The nanoemulsion formulations bearing nitrendipine were prepared by application of ternary phase diagram and spontaneous emulsification method. Box-behnken design was employed for the optimization of nitrendipine loaded nanoemulsion. The independent variables were oil, surfactant and co-surfactant while globule size, drug content and zeta potential were dependent variables. The optimized nanoemulsion formulation was incorporated into gel and evaluated for in-vitro release, ex-vivo permeation studies, confocal laser scanning microscopy, skin irritation and histopathological studies.Results: The optimized formulation through box-behnken statistical design showed globule size of 20.43 ± 1.50 nm, drug content of 97.05 ± 1.77% and zeta potential of -15.45 ± 0.35 mV. The ex-vivo study confirmed the enhanced delivery of nitrendipine from nanoemulsion gel than compare to drug solution by virtue of better permeation and solubility. Nanoemulsion gel was proved significantly superior by confocal laser scanning microscopy for satisfactory permeation and distribution of gel, deep into the rat skin. The optimized gel was found with no allergic dermal effects and was proved safe by histopathological studies for transdermal application.Conclusions: Results reveals that developed nitrendipine nanoemulsion gel overcomes the limitation of low penetration and accentuate permeation through albino Wistar rat skin. It was concluded that nanoemulsion gel could be utilized as a potential carrier for transdermal delivery of nitrendipine.

Preparation and Evaluation of Atorvastatin-Loaded Nanoemulgel on Wound-Healing Efficacy

Tissue repair and wound healing are complex processes that involve inflammation, granulation, and remodeling of the tissue. The potential of various statins including atorvastatin (ATR) to improve the wound healing effect was established. The aim of this study was to formulate and evaluate the efficacy of topical application of ATR-based nanoemulgel on wound healing. The prepared formulations (ATR gel, ATR emulgel, and ATR nanoemulgel) were evaluated for their physical appearance, rheological behavior, in vitro drug release and ex vivo drug permeation. The in vivo wound healing effect was evaluated in wound-induced rats. The prepared ATR gel formulations showed good physical properties and were comparable. The release profiles of drugs from gel, emulgel, and nanoemulgel were distinct. Skin permeation potential of ATR was significantly (p < 0.05) enhanced when formulated into nanoemulgel. In vivo wound healing studies showed that ATR nanoemulgel exhibited the highest percent wound contraction. Histopathological assessment showed marked improvement in the skin histological architecture after 21 days of ATR nanoemulgel treatment. In conclusion, the data demonstrated here signify the prospective of ATR nanoemulgel as an innovative therapeutic approach in wound healing.

Nanoemulsion: A Review on Mechanisms for the Transdermal Delivery of Hydrophobic and Hydrophilic Drugs

Nanoemulsions (NEs) are colloidal dispersions of two immiscible liquids, oil and water, in which one is dispersed in the other with the aid of a surfactant/co-surfactant mixture, either forming oil-in-water (o/w) or water-in-oil (w/o) nanodroplets systems, with droplets 20–200 nm in size. NEs are easy to prepare and upscale, and they show high variability in their components. They have proven to be very viable, non-invasive, and cost-effective nanocarriers for the enhanced transdermal delivery of a wide range of active compounds that tend to metabolize heavily or suffer from undesirable side effects when taken orally. In addition, the anti-microbial and anti-viral properties of NE components, leading to preservative-free formulations, make NE a very attractive approach for transdermal drug delivery. This review focuses on how NEs mechanistically deliver both lipophilic and hydrophilic drugs through skin layers to reach the blood stream, exerting the desired therapeutic effect. It highlights the mechanisms and strategies executed to effectively deliver drugs, both with o/w and w/o NE types, through the transdermal way. However, the mechanisms reported in the literature are highly diverse, to the extent that a definite mechanism is not conclusive.

In Vitro Drug Dissolution/Permeation Testing of Nanocarriers for Skin Application: a Comprehensive Review

This review highlights in vitro drug dissolution/permeation methods available for topical and transdermal nanocarriers that have been designed to modulate the propensity of drug release, drug penetration into skin, and permeation into systemic circulation. Presently, a few of USFDA-approved in vitro dissolution/permeation methods are available for skin product testing with no specific application to nanocarriers. Researchers are largely utilizing the in-house dissolution/permeation testing methods of nanocarriers. These drug release and permeation methods are pending to be standardized. Their biorelevance with reference to in vivo plasma concentration-time profiles requires further exploration to enable translation of in vitro data for in vivo or clinical performance prediction.

Formulation and Characterization of Eplerenone Nanoemulsion Liquisolids, An Oral Delivery System with Higher Release Rate and Improved Bioavailability

Because Eplerenone (EPL) is a Biopharmaceutical Classification System (BCS) class-II drug and is prone to extensive liver degradation, it suffers from poor bioavailability after oral administration. This work aimed to prepare liquisolids loaded with EPL-nanoemulsions (EPL-NEs) that have a higher drug release rate and improved bioavailability by the oral route. Based on solubility studies, mixtures of Triacetin (oil) and Kolliphor EL/PEG 400 surfactant/co-surfactant (Smix) in different ratios were used to prepare EPL-NE systems, which were characterized and optimized for droplet size, zeta potential, polydispersity index (PDI), and drug content. Systems were then loaded onto liquisolid formulations and fully evaluated. A liquisolid formulation with better drug release and tableting properties was selected and compared to EPL-NEs and conventional EPL oral tablets in solid-state characterization studies and bioavailability studies in rabbits. Only five NEs prepared at 1:3, 1:2, and 3:1 Smix met the specified optimization criteria. The drug release rate from liquisolids was significantly increased (90% within 45 minutes). EPL-NE also showed significantly improved drug release but with a sustained pattern for four hours. Liquisolid bioavailability reached 2.1 and 1.2 relative to conventional tablets and EPL-NE. This suggests that the EPL-NE liquisolid is a promising oral delivery system with a higher drug release rate, enhanced absorption, decreased liver degradation, and improved bioavailability.