In vitro/in vivo characterization of nanoemulsion formulation of metronidazole with improved skin targeting and anti-rosacea properties

Rosacea Topical Treatment and Care: From Traditional to New Drug Delivery Systems

Rosacea is a multifactorial chronic inflammatory dermatosis characterized by flushing, nontransient erythema, papules and pustules, telangiectasia, and phymatous alterations accompanied by itching, burning, or stinging, the pathophysiology of which is not yet fully understood. Conventional topical treatments usually show limited efficacy due to the physical barrier property of the skin that hinders skin penetration of the active ingredients, thereby hampering proper drug skin delivery and the respective therapeutic or cosmetic effects. New advances regarding the physiopathological understanding of the disease and the underlying mechanisms suggest the potential of new active ingredients as promising therapeutic and cosmetic approaches to this dermatosis. Additionally, the development of new drug delivery systems for skin delivery, particularly the potential of nanoparticles for the topical treatment and care of rosacea, has been described. Emphasis has been placed on their reduced nanometric size, which contributes to a significant improvement in the attainment of targeted skin drug delivery. In addition to the exposition of the known pathophysiology, epidemiology, diagnosis, and preventive measures, this Review covers the topical approaches used in the control of rosacea, including skin care, cosmetics, and topical therapies, as well as the future perspectives on these strategies.

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.

Development of Nanoemulsions for Topical Application of Mupirocin

Mupirocin (MUP) is a topical antibacterial agent used to treat superficial skin infections but has limited application due to in vivo inactivation and plasma protein binding. A nanoemulsion formulation has the potential to enhance the delivery of mupirocin into the skin. MUP-loaded nanoemulsions were prepared using eucalyptus oil (EO) or eucalyptol (EU), Tween^® 80 (T80) and Span^® 80 (S80) as oil phase (O), surfactant (S) and cosurfactant (CoS). The nanoemulsions were characterised and their potential to enhance delivery was assessed using an in vitro skin model. Optimised nanoemulsion formulations were prepared based on EO (MUP-NE EO) and EU (MUP-NE EU) separately. MUP-NE EO had a smaller size with mean droplet diameter of 35.89 ± 0.68 nm and narrower particle size index (PDI) 0.10 ± 0.02 nm compared to MUP-NE EU. Both nanoemulsion formulations were stable at 25 °C for three months with the ability to enhance the transdermal permeation of MUP as compared to the control, Bactroban^® cream. Inclusion of EU led to a two-fold increase in permeation of MUP compared to the control, while EO increased the percentage by 48% compared to the control. Additionally, more MUP was detected in the skin after 8 h following MUP-NE EU application, although MUP deposition from MUP-NE EO was higher after 24 h. It may be possible, through choice of essential oil to design nanoformulations for both acute and prophylactic management of topical infections.

Insightful exploring of advanced nanocarriers for the topical/transdermal treatment of skin diseases

Dermatological products constitute a big segment of the pharmaceutical market. From conventional products to more advanced ones, a wide variety of dosage forms have been developed till current date. A representative of the advanced delivery means is carrier-based systems, which can load large number of drugs for treatment of dermatological diseases, or simply for cosmeceutical purposes. To make them more favorable for topical delivery, further incorporation of these carriers in a topical vehicle, such as gels or creams is made. Therefore in this review article, an overview is compiled of the most commonly encountered novel carrier based topical delivery systems; namely lipid based (nanoemulsions, microemulsions, solid lipid nanoparticles [SLNs] and nanostructured lipid carriers [NLCs]), and vesicular carriers (non-deformable, such as liposomes, niosomes, emulsomes and cerosomes, and deformable, such as transfersomes, ethosomes, transethosomes, and penetration enhancer vesicles), with special emphasis on those loaded in a secondary gel vehicle. A special focus was made on the commonly encountered dermatological diseases, such as bacterial and fungal infections, psoriasis, dermatitis, eczema, vitiligo, oxidative damage, aging, alopecia, and skin cancer.

Murine models of rosacea: a review

Rosacea is a chronic inflammatory disease characterized by facial flushing, erythema, telangiectasia, papules, and pustules. Its pathogenesis has not been fully understood. In 2017, the global ROSacea COnsensus (ROSCO) panel updated the diagnosis, classification, and assessment of rosacea. Phenotype-based treatments and long-term managements have also been recommended. Murine models are a powerful tool in unveiling and dissecting the mechanisms of human diseases. Here, we summarized murine models of rosacea developed or used in previous research, including LL-37 intradermal injection model, KLK-5-induced inflammation model, croton oil inflammation model, 12-O-Tetradecanoylphorbol-13-acetate inflammation model, arachidonic acid inflammation model, RTX-induced vasodilation model, and UVB-induced model. LL-37 injection model has become the most intensively used model in rosacea research. Each model could show the pathophysiological and clinical features of rosacea to some extent. However, no model can show the full picture of the characteristics of rosacea. Improving existed murine models, developing new murine models, and applying them to pathogenesis and treatment research on rosacea are highly warranted in the future.

Preparation and Evaluation of Azelaic Acid Topical Microemulsion Formulation: In Vitro and In Vivo Study

The aim of this study was to design oil in water (O/W) microemulsion formulations for the topical administration of azelaic acid. The permeability of azelaic acid through rat skin and the anti-inflammatory activities of the formulations were conducted to examine the efficacy of the designed formulations. Skin irritation and stability tests were also performed. The permeability of azelaic acid was significantly increased by using O/W microemulsions as carriers. The edema index of ear swelling percentage was significantly recovered by the 5% drug-loaded formulation and a 20% commercial product, demonstrating that the experimental formulation possessed comparable effect with the commercial product on the improvement of inflammation. The experimental formulation did not cause significant skin irritation compared to the negative control group. Moreover, the drug-loaded formulation also showed thermodynamic stability and chemical stability after storage for 30 days. In conclusion, the O/W microemulsion was a potential drug delivery carrier for azelaic acid topical application.

Different Types of Gel Carriers as Metronidazole Delivery Systems to the Oral Mucosa

Periodontal diseases are some of the most widespread oral afflictions, and they are labeled as chronic infections caused by the accumulation of bacteria in dental plaque that produces localized inflammation of the periodontium. The use of local drug delivery systems to treat periodontal diseases has received greater attention, because the active substance is targeted directly to the affected area, which minimizes its systemic side effects. Therefore, the purpose of the investigation was to develop and characterize different types of gel formulations-bigel, hydrogel and oleogel-as local delivery systems containing metronidazole (MET), which can be applied to the oral mucosa. The influence of the formulation type on the mechanical, rheological and mucoadhesive properties were examined. Moreover, in vitro release of metronidazole, its ex vivo permeation through buccal porcine mucosa and antimicrobial activity measured by the plate diffusion method were estimated. It was found that the gel formulations obtained were non-Newtonian systems, showing a shear-thinning behavior and thixotropic properties with good textural features such as firmness, compressibility and adhesiveness. Moreover, the preparations designed possessed beneficial mucoadhesive properties. The formulated hydrogels and bigels containing micronized MET were considered as better formulations in terms of drug release and antimicrobial activity compared to commercially available metronidazole ointment. An ex vivo permeation study with the use of porcine buccal mucosa demonstrated that the bigel formulation was characterized by higher initial permeability rate providing a fast therapeutic effect with simultaneous moderate retention in mucosal tissue to decrease the risk of local cytotoxicity.

Metronidazole-loaded nanostructured lipid carriers to improve skin deposition and retention in the treatment of rosacea

The objective of the present investigation was to improve the skin deposition and retention of metronidazole (MTZ) in rosacea therapy by incorporating it into nanostructured lipid carriers (NLCs). The main challenge in this endeavor was the partial hydrophilicity of MTZ, which mandated careful selection of excipients, including solid and liquid lipids, surfactants, and their ratios in combination. NLCs were produced by the phase inversion temperature method and finally converted into a gel for topical application. The prepared nanoparticles were evaluated for their particle size, zeta potential, entrapment efficiency, solid-state characteristics, surface morphology, in vitro drug release, and permeation through excised skin. The gel was additionally characterized for its pH, drug content, viscosity, and spreadability. The prepared nanoparticles were spherical in shape and of size less than 300 nm. Incorporation of judiciously chosen excipients made possible a relatively high entrapment efficiency of almost 40%. The drug release was found to be biphasic, with an initial burst release followed by sustained release up to 8 hours. In comparison to the plain drug gel, which had a tissue deposition of 11.23%, the NLC gel showed a much superior and desirable deposition of 26.41%. The lipophilic nature of the carrier, its size, and property of occlusion enabled greater amounts of drug to enter and be retained in the skin, simultaneously minimizing permeation through the skin, i.e. systemic exposure. The results of the study suggest that NLCs of anti-rosacea drugs have the potential to be used in the therapy of rosacea.

Nanoemulsion strategy of pioglitazone for the treatment of skin inflammatory diseases

Pioglitazone (PGZ) is a peroxisome proliferator-activated receptor agonist. Its role in the inflammatory response modulation paves the way for additional therapeutic applications. The purpose of this study was to develop a pioglitazone nanoemulsion (PGZ-NE) in order to investigate its anti-inflammatory efficacy on the skin. To that end, an NE vehicle developed for skin delivery was optimized and characterized. The resulting PGZ-NE showed good anti-inflammatory efficacy by decreasing the expression of inflammatory cytokines IL-6, IL-1β and TNF-α. The properties of the developed nanocarrier allowed achievement of a high permeation flux of PGZ through the skin as well as a high retained amount in the skin, likely due to the depot effect of ingredients, which assured a prolonged local action, with good skin tolerability among participating individuals. Consequently, these results suggest that PGZ-NE may be used as an alternative treatment for inflammatory skin diseases such as rosacea, atopic dermatitis or psoriasis.

Stimulus Sensitive Smart Nanoplatforms: An Emerging Paradigm for the Treatment of Skin Diseases

Background:

Over the past century, the prevalence of skin diseases has substantially increased. These diseases present a significant physical, emotional and socio-economic burden to the society. Such conditions are also associated with a multitude of psychological traumas to the suffering patients. The effective treatment strategy implicates targeting of drugs to the skin. The field of drug targeting has been revolutionized with the advent of nanotechnology. The emergence of stimulus-responsive nanoplatforms has provided remarkable control over fundamental polymer properties for external triggers. This enhanced control has empowered pioneering approaches in the treatment of chronic inflammatory skin diseases.

Objective:

Our aim was to investigate the studies on smart nanoplatforms that exploit the altered skin physiology under diseased conditions and provide site-specific controlled drug delivery.

Method:

All literature search regarding the advances in stimulus sensitive smart nanoplatforms for skin diseases was done using Google Scholar and Pubmed.

Conclusion:

Various stimuli explored lately for such nano platforms are pH, temperature, light and magnet. Although, the scientists have actively taken up this research topic but there are still certain lacunaes associated which have been discussed in this review. Further, an interdisciplinary collaboration between the healthcare providers and pharmacists is a pivotal requirement for such systems to be available for patients.

Biopharmaceutical profile of a clotrimazole nanoemulsion: Evaluation on skin and mucosae as anticandidal agent

Clotrimazole (CLT) was formulated in a nanoemulsion (NE) for the topical treatment of candidiasis consisting of 10% labrafac^® lipophile, 60% labrasol^®:capryol^® 90 mixture (ratio 4:1) and 30% propylene glycol. Physicochemical properties, stability, rheology, in vitro drug release, ex vivo drug permeation through human skin and porcine buccal, sublingual and vaginal mucosae, antifungal efficacy, as well as in vivo skin tolerance were evaluated. 1% CLT-NE (CLT-NE1) and 2% CLT-NE (CLT-NE2) exhibited 153 ± 17.25 and 186 ± 15.38 nm droplet sizes, low polydispersity indexes, negative zeta potentials and biocompatible pH values. The CLT-NEs exhibited typical Newtonian profiles with viscosities of 42.14 ± 0.037 mPa·s and 41.35 ± 0.041 mPa·s, respectively and higher extensibility properties than commercial counterparts retaining their physicochemical properties for 180 days. NEs provided a sustained release of drug according to the first order model. Similar skin permeation properties were observed between CLT-NE1 and commercial reference. However, significant higher CLT amounts retained in mucosae were provided by CLT-NE2 when compared with references. Antifungal efficacies were also higher than commercial references, and the in vivo tolerance study confirmed the suitability for topical application, making CLT-NEs a great tool for clinical investigation of topical candidiasis treatments.

Biomedical applications of microemulsion through dermal and transdermal route

Microemulsions are thermodynamically stable, transparent, colloidal drug carrier system extensively used by the scientists for effective drug delivery across the skin. It is a spontaneous isotropic mixture of lipophilic and hydrophilic substances stabilized by suitable surfactant and co-surfactant. The easy fabrication, long-term stability, enhanced solubilization, biocompatibility, skin-friendly appearance and affinity for both the hydrophilic and lipophilic drug substances make it superior for skin drug delivery over the other carrier systems. The topical administration of most of the active compounds is impaired by limited skin permeability due to the presence of skin barriers. In this sequence, the microemulsion represents a cost-effective and convenient drug carrier system which successfully delivers the drug to and across the skin. In the present review work, we compiled various attempts made in last 20 years, utilizing the microemulsion for dermal and transdermal delivery of various drugs. The review emphasizes the potency of microemulsion for topical and transdermal drug delivery and its effect on drug permeability.

Development of a carboxymethyl chitosan functionalized nanoemulsion formulation for increasing aqueous solubility, stability and skin permeability of astaxanthin using low-energy method

In this research, firstly astaxanthin (ASX)-loaded nanoemulsions (NEs) were produced using a convenient low-energy emulsion phase inversion method. The optimised ASX-NEs were prepared in the presence of Cremophor^® EL and Labrafil^® M 1944 CS, with a surfactant-to-oil ratio of 4:6. The ASX-NE droplets were spherical with a mean droplet diameter below 100 nm and a small negative surface charge. The system was stable without alteration of mean droplet diameter for three months. Then, the ASX-NE was functionalised with carboxymethyl chitosan (CMCS) through direct CMCS (0.02%) incorporation during the preparation process. The ASX chemical stability and skin permeability increased in the following order: ASX solution control < ASX-NE < CMCS-ASX-NE. Cell viability assays on L929 cells revealed low cytotoxicity of blank NE, ASX-NE and CMCS-ASX-NE in the range from 5 to 500 μg mL^-1. In conclusion, the CMCS-ASX-NE might be a promising delivery vehicle in dermal and transdermal products.

Effect of oil structure on cyclodextrin-based Pickering emulsions for bupivacaine topical application

Cyclodextrins (CDs) coupled with oils forms an insoluble inclusion complex that is able to adsorb to the interface between oils and aqueous phases; it thereby stabilizes Pickering emulsions. Three types of oils (triglyceride, linear chain oil, and ring-structured oil) were chosen to work with CDs to prepare bupivacaine (BPC)-encapsulated Pickering emulsions. We also investigated the relationship between oils and CDs; as well as their influences on stability, drug-releasing capability and skin permeability. Particle sizes and microstructures were determined by dynamic light scattering and scanning electron microscopy, respectively. In vitro drug release studies and in vitro skin permeation studies were evaluated by using Franz diffusion model. Particle sizes of all Pickering emulsions were larger than 1μm, and the morphology was spherical and covered with rough surfaces. BPC was released over an extended period, and the releasing ratios from Pickering emulsions were only 12.2%-23.1% after 48h. In skin permeation studies, compared with other formulations, a formula involved with ring-structured oil allowed the highest permeation amount through skin. However, after 24h of exposure, formulation operated with linear chain oil showed the highest skin-retaining amount. These results suggest that Pickering emulsions could regulate the target site of skin depending on various types of oil used.

Size-dependent penetration of nanoemulsions into epidermis and hair follicles: implications for transdermal delivery and immunization

Nanoemulsions have been widely applied to dermal and transdermal drug delivery. However, whether and to what depth the integral nanoemulsions can permeate into the skin is not fully understood. In this study, an environment-responsive dye, P4, was loaded into nanoemulsions to track the transdermal translocation of the nanocarriers, while coumarin-6 was embedded to represent the cargoes. Particle size has great effects on the transdermal transportation of nanoemulsions. Integral nanoemulsions with particle size of 80 nm can diffuse into but not penetrate the viable epidermis. Instead, these nanoemulsions can efficiently fill the whole hair follicle canals and reach as deep as 588 μm underneath the dermal surfaces. The cargos are released from the nanoemulsions and diffuse into the surrounding dermal tissues. On the contrary, big nanoemulsions, with mean particle size of 500 nm, cannot penetrate the stratum corneum and can only migrate along the hair follicle canals. Nanoemulsions with median size, e.g. 200 nm, show moderate transdermal permeation effects among the three-size nanoemulsions. In addition, colocalization between nanoemulsions and immunofluorescence labeled antigen-presenting cells was observed in the epidermis and the hair follicles, implying possible capture of nanoemulsions by these cells. In conclusion, nanoemulsions are advantageous for transdermal delivery and potential in transcutaneous immunization.

Tacrolimus and curcumin co-loaded liposphere gel: Synergistic combination towards management of psoriasis

Psoriasis is an autoimmune skin disorder characterized by hyper proliferation and poor differentiation of keratinocytes. It significantly affects patient's quality of life. This study reports the anti-psoriatic efficacy of tacrolimus and curcumin loaded liposphere gel formulation. Poor solubility, poor skin penetration and erratic absorption are some problems associated with the topical delivery of these drugs. To overcome these problems, lipospheres containing combination of tacrolimus and curcumin was prepared with a particle size of nearly 50nm and incorporated into a gel for topical application. Liposphere gel showed slow release of both the drugs and shear thinning behaviour that is desirable property of topical formulation. Further, dermal distribution study using dye loaded formulation suggested penetration of dye into skin layers. The therapeutic efficacy of tacrolimus and curcumin loaded liposphere gel was assessed on imiquimod induced psoriatic plaque model, and the level of expression of psoriatic biochemical markers was evaluated using enzyme-linked immunosorbent assay. Results indicated improvement in the phenotypic and histopathological features of psoriatic skin treated with tacrolimus and curcumin loaded liposphere gel. There was reduction in the level of TNF-α, IL-17 and IL-22 compared to imiquimod group. These results corroborate the premise that liposphere gel containing combination of tacrolimus and curcumin can be an effective strategy for the treatment of psoriasis.

Preparation of a mixed-matrix hydrogel of vorinostat for topical administration on the rats as experimental model

Oral vorinostat has the remarkable curative effect on aggravated and recurrent cutaneous T-cell lymphoma (CTCL), but is accompanied by serious adverse effects. Therefore, oral vorinostat is not applicable to the treatment of early stage CTCL. The aim of this study is to develop a novel vorinostat formulation which is effective for early stage CTCL and free of the serious adverse effects. A mixed-matrix hydrogel of vorinostat was prepared and characterized as a potential topical skin delivery system. Moisture retention, swelling behavior, viscosity, real-time morphology and differential scanning calorimeter analysis (DSC) of hydrogel were evaluated to select the solvent, matrix and humectant. The optimal HPMC/HPC ratio, pH, additive, dose and drug loading of vorinostat hydrogel were determined by evaluating the cumulative vorinostat amount of skin retention and transdermal amount of vorinostat through the skin in vitro. The optimal hydrogel presented a low transdermal amount of vorinostat through the skin, suggesting that the hydrogel reduced the amount of vorinostat that was absorbed in the systemic circulation. More importantly, in vivo percutaneous permeation experiments were also performed to evaluate the permeation behavior of vorinostat into the skin. The topical application with a much lower dose showed higher AUC (the cumulative vorinostat amount of skin retention) than oral application and the hydrogel achieved a sustained permeation of vorinostat in the skin for 24h in vivo. It indicated that a higher relative bioavailability for hydrogel was achieved compared with oral vorinostat. Moreover, there was no damage, inflammation or cell swelling of the skin after administration. Thus, the mixed-matrix vorinostat hydrogel prepared in this study could deliver vorinostat into local skin more efficiently than oral administration.

A novel topical targeting system of caffeine microemulsion for inhibiting UVB-induced skin tumor: characterization, optimization, and evaluation

The purpose of the present study was to develop an optimal microemulsion (ME) formulation as topical nanocarrier of caffeine (CAF) to enhance CAF skin retention and subsequently improve its therapeutic effect on UVB-induced skin carcinogenesis. The pseudo-ternary phase diagram was developed composing of Labrafil M 1944 CS as oil phase, Cremophor EL as surfactant, tetraglycol as cosurfactant, and water. Four ME formulations at water content of 50, 60, 70, and 80% were prepared along the water dilution line of oil to surfactant ratio of 1:3 and characterized in terms of morphology, droplet size, and electric conductivity. A gel at the same drug loads (1%, w/w) was used as control. Ex vivo skin permeation studies were conducted for ME optimization. The optimized formulation (ME4) was composed of 5% (w/w) Labrafil M 1944 CS, 15% (w/w) Smix (2/1, Cremophor EL and tetraglycol), and 80% (w/w) aqueous phase. The skin location amount of CAF from ME4 was nearly 3-fold higher than control (P < 0.05) with improved permeated amount through the skin. The skin targeting localization of hydrophilic substance from ME4 was further visualized through fluorescent-labeled ME by a confocal laser scanning microscope. In pharmacodynamics studies, CAF-loaded ME4 was superior in terms of increasing apoptotic sunburn cells (P < 0.05) as compared with control. Overall results suggested that the ME4 might be a promising vehicle for the topical delivery of CAF.

Synergetic skin targeting effect of hydroxypropyl-β-cyclodextrin combined with microemulsion for ketoconazole

The objective was to develop a ternary skin targeting system for ketoconazole (KET) using a combined strategy of microemulsion (ME) and cyclodextrin (HP-β-CD), i.e., KET-CD-ME, which exploits both virtues of cyclodextrin complex and ME to obtain the synergetic effect. KET-CD-ME was formulated using Labrafil M 1944 CS as oil phase, Solutol HS 15 as surfactant, Transcutol P as cosurfactant, and HP-β-CD solution as aqueous phase. The formulation of KET-CD-ME was optimized and the optimal formulation was characterized in terms of particle size, size distribution, pH value, and viscosity. Long term stability experiment showed that HP-β-CD could increase the physical stability of ternary system and KET chemical stability. Percutaneous permeation of KET from KET-CD-ME in vitro through rat skin was investigated in comparison with KET microemulsion (KET-ME), KET HP-β-CD inclusion solution (KET-CD), KET aqueous suspension, and commercial KET cream; the results showed that the combination of ME with HP-β-CD exhibited significantly synergistic effect on KET deposition within the skin (29.38 ± 1.79 μg/cm(2)) and a slightly synergistic effect on KET penetration through the skin (11.3 μg/cm(2)/h). The enhancement of the combination on skin deposition was further visualized by confocal laser scanning microscope (CLSM). In vitro sensitivity against Candida parapsilosis test indicated that KET-CD-ME enhanced KET antifungal activity mainly owing to the solubilization of HP-β-CD on KET in the ternary system. Moreover, the interactions between HP-β-CD and KET in the ternary system were elucidated through microScale thermophoresis (MST) and 2D (1)H NMR spectroscopy. The profiles from MST confirmed the host-guest interactions of HP-β-CD with KET in the ternary system and a deep insight into the interactions between KET and HP-β-CD were obtained by means of 2D (1)H NMR spectroscopy. The results indicate that the ternary system of ME combination with HP-β-CD may be a promising approach for skin targeting delivery of KET.

Formulation design for topical drug and nanoparticle treatment of skin disease

The skin has evolved to resist the penetration of foreign substances and particles. Topical therapeutic and cosmeceutical delivery is a growing field founded on selectively overcoming this barrier. Both the biology of the skin and the nature of the formulation/active ingredient must be aligned for efficient transcutaneous delivery. This review discusses the biological changes in the skin barrier that occur with common dermatological conditions. This context is the foundation for the discussion of formulation strategies to improve penetration profiles of common active ingredients in dermatology. Finally, we compare and contrast those approaches to recent advances described in the research literature with an eye toward the future of topical formulation design.

Improved percutaneous delivery of azelaic acid employing microemulsion as nanocarrier: formulation optimization, in vitro and in vivo evaluation

Topical administration of an optimal microemulsion could effectively enhance the amount of azelaic acid in skin without causing skin irritation.

Nanomiemgel--a novel drug delivery system for topical application--in vitro and in vivo evaluation

Aim

The objective of this study was to formulate and evaluate a unique matrix mixture (nanomiemgel) of nanomicelle and nanoemulsion containing aceclofenac and capsaicin using in vitro and in vivo analyses and to compare it to a marketed formulation (Aceproxyvon).

Methods

Nanomicelles were prepared using Vitamin E TPGS by solvent evaporation method and nanoemulsion was prepared by high-pressure homogenization method. In vitro drug release and human skin permeation studies were performed and analyzed using HPLC. The efficiency of nanomiemgel as a delivery system was investigated using an imiquimod-induced psoriatic like plaque model developed in C57BL/6 mice.

Results

Atomic Force Microscopy images of the samples exhibited a globular morphology with an average diameter of 200, 250 and 220 nm for NMI, NEM and NMG, respectively. Nanomiemgel demonstrated a controlled release drug pattern and induced 2.02 and 1.97-fold more permeation of aceclofenac and capsaicin, respectively than Aceproxyvon through dermatomed human skin. Nanomiemgel also showed 2.94 and 2.09-fold greater Cmax of aceclofenac and capsaicin, respectively than Aceproxyvon in skin microdialysis study in rats. The PASI score, ear thickness and spleen weight of the imiquimod-induced psoriatic-like plaque model were significantly (p<0.05) reduced in NMG treated mice compared to free drug, NEM, NMI & Aceproxyvon.

Conclusion

Using a new combination of two different drug delivery systems (NEM+NMI), the absorption of the combined system (NMG) was found to be better than either of the individual drug delivery systems due to the utilization of the maximum possible paths of absorption available for that particular drug.