Nitazoxanide and quercetin co-loaded nanotransfersomal gel for topical treatment of cutaneous leishmaniasis with macrophage targeting and enhanced anti-leishmanial effect

Purpose

Anti-leishmanial medications administered by oral and parenteral routes are less effective for treatment of cutaneous leishmaniasis (CL) and cause toxicity, hence targeted drug delivery is an efficient way to improve drug availability for CL with reduced toxicity. This study aimed to develop, characterize and evaluate nitazoxanide and quercetin co-loaded nanotransfersomal gel (NTZ-QUR-NTG) for the treatment of CL.

Methods

NTZ-QUR-NT were prepared by thin film hydration method and were statistically optimized using Box-Behnken design. To ease the topical delivery and enhance the retention time, the NTZ-QUR-NT were dispersed in 2 % chitosan gel. Moreover, in-vitro drug release, ex-vivo permeation, macrophage uptake, cytotoxicity and anti-leishmanial assays were performed.

Results

The optimized formulation indicated mean particle size 210 nm, poly dispersity index (PDI) 0.16, zeta potential (ZP) -15.1 mV and entrapment efficiency (EE) of NTZ and QUR was 88 % and 85 %, respectively. NTZ-QUR-NT and NTZ-QUR-NTG showed sustained release of the incorporated drugs as compared to the drug dispersions. Skin permeation of NTZ and QUR in NTZ-QUR-NTG was 4 times higher in comparison to the plain gels. The NTZ-QUR-NT cell internalization was almost 10-folds higher than NTZ-QUR dispersion. The cytotoxicity potential (CC50) of NTZ-QUR-NT (71.95 ± 3.32 μg/mL) was reduced as compared to NTZ-QUR dispersion (49.77 ± 2.15 μg/mL. A synergistic interaction was found between NTZ and QUR. Moreover, in-vitro anti-leishmanial assay presented a lower IC50 value of NTZ-QUR-NT as compared to NTZ-QUR dispersion. Additionally, a significantly reduced lesion size was observed in NTZ-QUR-NTG treated BALB/c mice, indicating its antileishmanial potential.

Conclusion

It can be concluded that nanotransfersomal gel has the capability to retain and permeate the incorporated drugs through stratum corneum and induce synergetic anti-leishmanial effect of NTZ and QUR against cutaneous leishmaniasis.

Betamethasone Dipropionate Nanocrystals: Investigation, Feasibility and In Vitro Evaluation

Corticosteroids, such as betamethasone dipropionate (BMD), have been the mainstay in topical therapy as potent glucocorticoid receptor agonist with immune suppression, anti-proliferative, and anti-inflammatory effects. Moreover, they have poor skin penetration, which is a hurdle against its potential therapeutic benefits. In present investigation, nanocrystals as carrier for effective topical delivery of BMD were explored using wet milling as technique and polysorbate 80 as a non-ionic stabilizer. Upon optimizing different process parameters, promising results were observed at stabilizer concentration of 0.9% w/v having particle size analysis (PSA) and PDI as 284 nm and 0.299, respectively. These results were supported by the FTIR and PXRD spectra of BMD-API and BMD nanocrystals, suggesting strong crystal lattice structure of BMD being reduced due to milling. The reduction in particle morphology was evident from the FESEM images. The optimized batch of BMD nanocrystals was incorporated into Carbopol gel base, showing pH 6.2 ± 0.2 and viscosity 87.00 ± 5.2 Pa s at 25°C. A drug diffusion study using Franz diffusion cell proclaimed around ~86% BMD release from nanogel across the membrane. Also, it was observed that the BMD permeation across the skin was 2.39-fold higher with marketed formulation in contrast to BMD nanogel, suggesting prolonged drug release. The skin permeation flux with nanogel was at a much lower rate along with ~50.27% drug retention in different strata of skin, resulting in retention of drug nanocrystals. Thus, in nutshell the prolonged drug release from nanogel would fulfill the aim of once a day application and would aid in reducing the adverse events associated with repeated drug applications.

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.

Olive Oil Based Methotrexate Loaded Topical Nanoemulsion Gel for the Treatment of Imiquimod Induced Psoriasis-like Skin Inflammation in an Animal Model

Simple Summary

Psoriasis, being chronic inflammatory illness, provoked by genetic and environmental factors is linked to several other life-threatening diseases. Methotrexate is regarded as gold standard for the management of psoriasis, so an attempt was made to incorporate this drug into nanoemulsion gel. Thus olive oil based formulation was fabricated to target animal model induced psoriasis- like skin inflammation. The optimized methotrexate nanoemulsion gel formulation produced a psoriasis area and severity Index (PASI) decrease that was similar or better than the 91% reduction seen in the methotrexate tablet group. The results of this study revealed effectiveness of methotrexate nanoemulsion gel formulation to treat psoriasis and reduce the remission of psoriasis-like symptoms.

Abstract

Psoriasis, a chronic inflammatory illness, is on the rise and is linked to several other life-threatening diseases. The primary goal of this study was to create a nanoemulsion gel loaded with methotrexate and olive oil (MTX NEG). The formulation was evaluated for physicochemical characterization, entrapment efficiency, drug release kinetics, skin permeation studies and stability tests. In addition, the efficacy of MTX NEG against psoriasis was tested using imiquimod-induced psoriasis in a rat model. The final optimized MTX NEG was developed with a particle size of 202.6 ± 11.59 nm and a PDI of 0.233 ± 0.01, with a 76.57 ± 2.48% average entrapment efficiency. After 20 h, the release kinetics predicted a 72.47% drug release at pH 5.5. FTIR findings demonstrated that the optimized MTX NEG formulation effectively fluidized both the epidermis and dermis of the skin, potentially increasing drug permeability and retention. The application of Tween 80 and PEG 400, on the other hand, significantly enhanced these effects, as these are well known penetration enhancers. After 24 h, an average of 70.78 ± 5.8 μg/cm² of methotrexate was permeated from the nanoemulsion gel with a flux value of 2.078 ± 0.42 μg/cm²/h, according to permeation measurements. Finally, in vivo experiments on rabbit skin revealed that the increased skin penetration of methotrexate-loaded nanoemulsion gel was not due to structural alterations in intercellular lipid layers in the stratum corneum. In vivo antipsoriatic studies on rats revealed that MTX NEG produced a PASI decrease that was extremely similar and even better than the 91% reduction seen in the MTX tablet group. According to the pharmacokinetic profile, Cmax was 8.5 μg/mL, Tmax was 12 h, and t1/2 was 15.5 ± 2.37 h. These findings reinforce that MTX-NEG based on olive oil could be a possible treatment for psoriasis and could decrease the remission of psoriasis-like symptoms.

Macrophage targeting with the novel carbopol-based miltefosine-loaded transfersomal gel for the treatment of cutaneous leishmaniasis: in vitro and in vivo analyses

OBJECTIVE

The purpose of this study was to develop novel carbopol-based miltefosine-loaded transfersomal gel (HePCTG) for the treatment of cutaneous leishmaniasis (CL) via efficient targeting of leishmania infected macrophages.

METHODS

Miltefosine-loaded transfersomes (HePCT) were prepared by ethanol injection method followed by their incorporation into carbopol gel to form HePCTG. The prepared HePCT were assessed for physicochemical properties including mean particle size, polydispersity index, zeta potential, entrapment efficiency, morphology, and deformability. Similarly, HePCTG was evaluated for physiochemical and rheological attributes. The in vitro release, skin permeation, skin irritation, anti-leishmanial activity, and in vivo efficacy in BALB/c mice against infected macrophages were also performed for HePCT.

RESULTS

The optimized HePCT displayed a particle size of 168 nm with entrapment efficiency of 92%. HePCTG showed suitable viscosity, pH, and sustained release of the incorporated drug. Furthermore, HePCT and HePCTG demonstrated higher skin permeation than drug solution. The results of macrophage uptake study indicated improved drug intake by passive diffusion. The lower half maximal inhibitory concentration value, selectivity index and higher 50% cytotoxic concentration  value of HePCT compared to that of HePC solution demonstrated the improved anti-leishmanial efficacy and non-toxicity of the formulation. This was further confirmed by the notable reduction in parasite load and lesion size observed in in vivo anti-leishmanial study.

CONCLUSION

It can be stated that the formulated HePCTG can effectively be used for the treatment of CL.

Novel Vitamin E TPGS based docetaxel nanovesicle formulation for its safe and effective parenteral delivery: Toxicological, pharmacokinetic and pharmacodynamic evaluation

Docetaxel (DTX) is a highly lipophilic, BCS class IV drug with poor aqueous solubility (12.7 µg/mL). Presently, only injectable formulation is available in the market which uses a large amount of surfactant (Tween 80) and dehydrated alcohol as a solubilizer. High concentrations of Tween 80 in injectable formulations are associated with severe consequences i.e. nephrotoxicity, fluid retention, and hypersensitivity reactions. The present study aims to eliminate Tween 80, thus novel biocompatible surfactant Vitamin E TPGS based nanovesicle formulation of DTX (20 mg/mL) was developed and evaluated for different quality control parameters. Optimized nanovesicular formulation (NV-TPGS-3) showed nanometric size (102.9 ± 2.9 nm), spherical vesicular shape, high drug encapsulation efficiency (95.2 ± 0.5%), sustained-release profile and high dilution integrity with normal saline. In vitro cytotoxicity assay, showed threefold elevation in the IC₅₀ value of the optimized formulation in comparison to the commercial formulation. Further, no mortality and toxicity were observed during 28 days repeated dose sub-acute toxicity studies in Swiss albino mice up to the dose of 138 mg/kg, whereas, commercial formulation showed toxicity at 40 mg/kg. In addition, in vivo anticancer activity on Ehrlich Ascites Carcinoma induced mice showed a significant tumour growth inhibition of 76.3 ± 5.3% with the NV-TPGS-3 treatment when compared to Ehrlich Ascites Carcinoma control. Results demonstrated that the developed Vitamin E TPGS based nanovesicular formulation of DTX could be a better alternative to increase its clinical uses with improved therapeutic efficacy, reduced toxicity and dosing frequency, and sustained drug release behaviour.

Development and Characterization of a Semi-Solid Dosage Form of Meglumine Antimoniate for Topical Treatment of Cutaneous Leishmaniasis

Cutaneous leishmaniasis (CL) is treated with painful intralesional injections of meglumine antimoniate (MA). With the aim of developing an alternative topical treatment for CL, a gel-based formulation with 30% MA was prepared and its physicochemical properties, stability and rheological behavior were studied. The following were assessed: drug release on propylene hydrophilic membranes ex vivo human skin permeation, tolerance in healthy volunteers, cytotoxicity in three cell lines and anti-leishmanial activity against Leishmania infantum promastigotes and amastigotes. The MA gel formulation was found to have suitable pH, and good spreadability and stability. Low quantities of pentavalent antimony (Sb^V) were observed in release and permeation tests, whereas retention was high in both non-damaged and damaged skin (71,043.69 ± 10,641.57 and 10,728 ± 2254.61 µg/g/cm² of Sb^V, respectively). The formulation did not have a toxic effect on the cell lines, and presented lower Sb^V IC₅₀ values against amastigotes (15.76 ± 4.81 µg/mL) in comparison with the MA solution. The high amount of drug retained in the skin and the Sb^V IC₅₀ values obtained suggest that this semi-solid dosage form has potential as an alternative treatment of CL.

Linolenic acid-modified MPEG-PEI micelles for encapsulation of amphotericin B

Aim: To encapsulate amphotericin B (AmB) with reduced toxicity and comparable activity. Results & methodology: The α-linolenic acid (ALA)-modified monomethoxy polyethylene glycol-g-PEI-g-ALA conjugate was employed to prepare AmB-loaded micelles (AmB-M). In vitro activity and release behavior of AmB-M were investigated. AmB-M enhanced AmB's water-solubility to 1.2 mg/ml, showing good storage stability. AmB-M could achieve a sustained and slow release of AmB, low hemolysis activity and negligible kidney toxicity when compared with commercial AmB injection. Antifungal activity and biofilm inhibition experiments confirmed that the antifungal activity of AmB-M against Candida albicans was similar to that of AmB injection. Conclusion: Monomethoxy polyethylene glycol-g-PEI-g-ALA micelles could be a preferable choice to treat systemic fungal infections as an efficient drug delivery system.

Impact of Process Parameters on Particle Size Involved in Media Milling Technique Used for Preparing Clotrimazole Nanocrystals for the Management of Cutaneous Candidiasis

Clotrimazole is widely used for the management of cutaneous candidiasis infection. The low solubility of clotrimazole and excipient-related topical side effects (of currently available marketed products) cause the compromised efficacy of the therapy with poor patient compliance. In the present investigation, a clotrimazole nanocrystal-based nanogel was developed. Clotrimazole nanocrystals were optimized with studying the impact of individual process parameters of the media milling technique. The optimum level of individual process parameters was considered in the development of optimized batches. A promising result was obtained with a non-ionic stabilizer, polysorbate 80, at a concentration of 1.5%w/v, showing a distinct reduction in the particle size from above 31 μm to 264 nm and a polydispersity index of 0.211 with media milling at 1500 rpm for 6 h. This result was found to be in concordance with the TEM images, revealing a sharp diminution in particle morphology. Powder X-ray diffraction and differential scanning calorimetry results revealed crystallinity of clotrimazole (CTZ) in nanocrystal form. The optimized nanocrystal suspension was formulated into nanogel with carbopol 934, having a viscosity of 86.43 ± 2.06 Pa s at 25°C, which enhanced the ease of application of CTZ nanocrystals topically. A diffusion study showed around 82% of CTZ is transported across the membrane with the flux of 110.07 μg cm^-2 h^-1. In vivo results of the nanogel revealed improvement in CTZ release with 52% CTZ retention in different strata of the skin. The developed nanogel showed a significant improvement in the eradication of fungal infection within 10 days of application over Candida albicans-induced Wistar rat model. In a nutshell, the CTZ nanocrystal-loaded nanogel could achieve the goal of retaining CTZ in skin layers providing a prolonged effect and was able to treat cutaneous candidiasis in a short span with improved compliance for the candidiasis patients.

Sodium stibogluconate loaded nano-deformable liposomes for topical treatment of leishmaniasis: macrophage as a target cell

Topical drug delivery against cutaneous leishmaniasis (CL) signifies an effective alternate for improving the availability and reducing the toxicity associated with the parenteral administration of conventional sodium stibogluconate (SSG) injection. The basic aim of the study was to develop nano-deformable liposomes (NDLs) for the dermal delivery of SSG against CL. NDLs were formulated by a modified thin film hydration method and optimized via Box–Behnken statistical design. The physicochemical properties of SSG-NDLs were established in terms of vesicle size (195.1 nm), polydispersity index (0.158), zeta potential (−32.8 mV), and entrapment efficiency (35.26%). Moreover, deformability index, in vitro release, and macrophage uptake studies were also accomplished. SSG-NDLs were entrapped within Carbopol gel network for the ease of skin application. The ex vivo skin permeation study revealed that SSG-NDLs gel provided 10-fold higher skin retention towards the deeper skin layers, attained without use of classical permeation enhancers. Moreover, in vivo skin irritation and histopathological studies verified safety of the topically applied formulation. Interestingly, the cytotoxic potential of SSG-NDLs (1.3 mg/ml) was higher than plain SSG (1.65 mg/ml). The anti-leishmanial activity on intramacrophage amastigote model of Leishmania tropica showed that IC₅₀ value of the SSG-NDLs was ∼ fourfold lower than the plain drug solution with marked increase in the selectivity index. The in vivo results displayed higher anti-leishmanial activity by efficiently healing lesion and successfully reducing parasite burden. Concisely, the outcomes indicated that the targeted delivery of SSG could be accomplished by using topically applied NDLs for the effective treatment of CL.

A Mechanistic Study to Determine the Structural Similarities Between Artificial Membrane Strat-M™ and Biological Membranes and Its Application to Carry Out Skin Permeation Study of Amphotericin B Nanoformulations

Type of biological membrane used in skin permeation experiment significantly affects skin permeation and deposition potential of tested formulations. In this study, a comparative study has been carried out to evaluate the potential of a synthetic membrane (Strat-M™) with rat, human, and porcine ear skin to carry out skin permeation study of nanoformulations of a high molecular weight drug, amphotericin B. Results demonstrated that the permeation of this high molecular weight drug through Strat-M™ showed close similitude to human skin. Value of correlation coefficient (R²) of log diffusion between Strat-M™ and human skin was found to be 0.99 which demonstrated the similarities of Strat-M™ membrane to the human skin. In similarity factor analysis, the value of f₂ was also found to be 85, which further demonstrated the similarities of Strat-M™ membrane to human skin. Moreover, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analysis of synthetic and biological membranes depicted almost similar morphological features (thickness, pore size, surface morphology, and diameter) of synthetic membrane with human skin. The results of the study demonstrated Strat-M™ as a better alternative to carry out skin permeation experiment due to the consistent results, reproducibility, easy availability, and minimum variability with human skin.