Novel topical formulations of Terbinafine-HCl for treatment of onychomycosis

Novel Discoveries and Clinical Advancements for Treating Onychomycosis: A Mechanistic Insight

Onychomycosis continues to be the most challenging disease condition for pharmaceutical scientists to develop an effective drug delivery system. Treatment challenges lie in incomplete cure and high relapse rate. Present compilation provides cumulative information on pathophysiology, diagnostic techniques, and conventional treatment strategies to manage onychomycosis. Novel technologies developed for successful delivery of antifungal molecules are also discussed in brief. Multidirectional information offered by this article also unlocks the panoramic view of leading patented technologies and clinical trials. The obtained clinical landscape recommends the use of advanced technology driven approaches, as a promising way-out for treatment of onychomycosis. Collectively, present review warrants the application of novel technologies for the successful management of onychomycosis. This review will assist readers to envision a better understanding about the technologies available for combating onychomycosis. We also trust that these contributions address and certainly will encourage the design and development of nanocarriers-based delivery vehicles for effective management of onychomycosis.

Development and Characterization of Terbinafine-Loaded Nanoemulgel for Effective Management of Dermatophytosis

Dermatophytosis, the most prevalent fungal infection, is witnessing a rising incidence annually. To address this challenge, we developed a terbinafine-loaded oil-in-water nanoemulsion (TH-NE) through the aqueous microtitration method. The formulation comprised olive oil (oil phase), Span 80 (surfactant), and propylene glycol (co-surfactant). Pseudo-phase ternary diagrams and thermodynamic studies underscored the stability of TH-NE. Employing the Box-Behnken design (BBD), we optimized TH-NE, which resulted in a remarkable particle size of 28.07 nm ± 0.5, a low polydispersity index (PDI) of 0.1922 ± 0.1, and a substantial negative zeta potential of -41.87 mV ± 1. Subsequently, TH-NE was integrated into a 1.5% carbopol matrix, yielding a nanoemulgel (TH-NEG). Texture analysis of TH-NEG demonstrated a firmness of 168.00 g, a consistency of 229.81 g/s, negative cohesiveness (-83.36 g), and a work of cohesion at -107.02 g/s. In vitro drug release studies revealed an initial burst effect followed by sustained release, with TH-NEG achieving an impressive 88% release over 48 h, outperforming TH-NE (74%) and the marketed formulation (66%). Ex vivo release studies mirrored these results, with TH-NEG (86%) and TH-NE (71%) showcasing sustained drug release in comparison to the marketed formulation (67%). Confocal microscopy illustrated that TH-NEG and TH-NE penetrated to depths of 30 µm and 25 µm, respectively, into the epidermal layer. Furthermore, dermatokinetic studies highlighted the enhanced drug penetration of TH-NEG compared to TH-NE through mouse skin. In summary, our study establishes TH-NEG as a promising carrier for terbinafine in treating dermatophytosis, offering improved drug delivery and sustained release potential.

Contemporary Techniques and Potential Transungual Drug Delivery Nanosystems for The Treatment of Onychomycosis

The humanoid nail is considered an exceptional protective barrier that is formed mainly from keratin. Onychomycosis is the cause of 50% of nail infections that is generally caused by dermatophytes. Firstly, the infection was regarded as a cosmetic problem but because of the tenacious nature of onychomycosis and its relapses, these infections have attracted medical attention. The first line of therapy was the oral antifungal agents which were proven to be effective; nevertheless, they exhibited hepato-toxic side effects, alongside drug interactions. Following, the opportunity was shifted to the topical remedies, as onychomycosis is rather superficial, yet this route is hindered by the keratinized layers in the nail plate. A potential alternative to overcome the obstacle was applying different mechanical, physical, and chemical methods to boost the penetration of drugs through the nail plate. Unfortunately, these methods might be expensive, require an expert to be completed, or even be followed by pain or more serious side effects. Furthermore, topical formulations such as nail lacquers and patches do not provide enough sustaining effects. Recently, newer therapies such as nanovesicles, nanoparticles, and nanoemulsions have emerged for the treatment of onychomycosis that provided effective treatment with possibly no side effects. This review states the treatment strategies such as mechanical, physical, and chemical methods, and highlights various innovative dosage forms and nanosystems developed in the last 10 years with a focus on advanced findings regarding formulation systems. Furthermore, it demonstrates the natural bioactives and their formulation as nanosystems, and the most relevant clinical outcomes.

Protection of hair color with pomegranate peel extract-loaded liposomal formulation: Preparation, characterization, and ex-vivo activity studies

BACKGROUND

Pomegranate peel extract is known as a powerful antioxidant and due to preventing oxidation, it can reduce color change of dyed hair after washing. Liposomes are vesicular systems that include lipids and can form a film on hair fibers. Delivery system and active agent have a synergistic effect on protecting hair color and reducing dyeing frequency.

AIMS

This study aimed to prepare liposomes suspension as an innovative formulation of pomegranate peel extract to reduce hair color changing.

METHODS

Pomegranate peel extract-loaded liposomes were prepared with lipidic film hydration method. The characterizations of formulations (F1 and F2) were defined by several parameters. The pH, particle size, polydispersity index, zeta potential, microscopical image, loading capacity (LC), and encapsulation efficiency (EE) of formulations were determined. The antioxidant capacity of formulations and actives were tested. The effect of formulations on hair color change was shown with ex-vivo studies.

RESULTS

The results showed that cholesterol influenced particle size, zeta potential, and antioxidant capacity. The particle sizes of formulations were 217.71 ± 6.74 nm and 577.5 ± 1.41 nm for F1 and F2, respectively. F2 formulation had better results for zeta potential (33.8 mV) while F1 was neutral. Morphologic images confirmed vesicular structure or liposomes. The EE was found higher for F2 than F1 (F1: 57.14 and F2: 78.69). Antioxidant studies confirmed that active substance and the vesicular system had a synergistic effect on protection from oxidation. Selected formulation reduced hair color change as shown in ex-vivo tests.

CONCLUSION

Pomegranate peel extract-loaded liposomes were designed for hair color protection. It was shown with this study that prepared formulations have a good color protection on hair fibers due to antioxidant properties of pomegranate peel extract and film forming effect of liposomal formulations. According to results, prepared liposomal formulations may serve as a good alternative for reducing dyeing frequency and protecting hair fibers.

Chitosan Nanoparticles Loaded Poloxamer 407 Gel for Transungual Delivery of Terbinafine HCl

The current study aimed to develop chitosan nanoparticles (CSNP) loaded poloxamer 407 (P407) gel formulation for transungual delivery of terbinafine HCl (TBN). TBN-CSNP were prepared by nanoprecipitation method and optimized by face-centered central composite design (FCCCD). Optimized TBN-CSNP formulation exhibited a spherical shape with hydrodynamic diameter; zeta potential and entrapment efficiency (EE) of 229 ± 5 nm; 37 ± 1.5 mV; and 75 ± 2% respectively. The solid state of TBN and its compatibility with formulation ingredients were confirmed through XRD and FTIR analysis respectively. TBN-CSNP loaded P407 gel exhibited pseudoplastic rheological behavior having a spreadability of 11 ± 2 g·cm/s. The washability study showed that 40 ± 2% of the gel was eroded after washing 12 times. Drug release from TBN-CSNP- and TBN-CSNP-loaded gel was 84 ± 5% and 57 ± 3%, respectively. The cumulative quantity of TBN permeated from TBN-CSNP-loaded P407 gel and TBN-loaded P407 gel was 25 ± 8 and 27 ± 4 µg/cm2, respectively. The nail uptake study showed that 3.6 ± 0.7 and 2.1 ± 0.3 µg of rhodamine was uptaken by the nail following 2 h topical application of TBN-CSNP loaded P407 gel and TBN loaded P407 gel, respectively. Hence, the developed CSNP-based P407 gel formulation can be a potential carrier for transungual delivery of TBN to topically treat onychomycosis.

Quality by Design Guided Development of Polymeric Nanospheres of Terbinafine Hydrochloride for Topical Treatment of Onychomycosis Using a Nano-Gel Formulation

Superficial fungal diseases of the skin and nails are an increasingly common occurrence globally, requiring effective topical treatment to avoid systemic adverse effects. Polymeric nanoparticles have demonstrated sustained and effective drug delivery in a variety of topical formulations. The aim of this project was to develop polymeric antifungal nanospheres containing terbinafine hydrochloride (TBH) to be loaded into a hydrogel formulation for topical nail drug delivery. A quality by design (QbD) approach was used to achieve optimized particles with the desired quality target product profile (QTPP). Polyvinyl alcohol (PVA) at 2% w/v and a drug to polymer ratio of 1:4, together with a robust set of processes and material attributes, resulted in nanoparticles of 108.7 nm with a polydispersity index (PDI) of 0.63, 57.43% recovery, and other desirable characteristics such as zeta potential (ZP), particle shape, aggregation, etc. The nanospheres were incorporated into a carbomer-based gel, and the delivery of TBH through this formulation was evaluated by means of in vitro drug release testing (IVRT) and ex vivo nail permeation study. The gel containing the TBH nanospheres demonstrated a slower and controlled drug release profile compared with the control gel, in addition to a more efficient delivery into the nail. These antifungal nanospheres can be utilized for topical therapy of a multitude of superficial fungal infections.

EthoLeciplex: A new tool for effective cutaneous delivery of minoxidil

This work designates EthoLeciplex, a vesicular system consisting of phospholipid, CTAB, ethanol and water, as an innovative vesicular system for cutaneous/transfollicular minoxidil delivery. Minoxidil loaded EthoLeciplex was fabricated by one-step fabrication process. Formulations were designed to study the effects of drug/phospholipid ratio, CTAB/phospholipid ratio, and ethanol concentration on vesicular size, PDI, surface charge and EE%. The optimized formulation was characterized by in vitro release, drug/excipient compatibility, ex vivo skin permeability and safety. A size of 83.6 ± 7.3 to 530.3 ± 29.4 nm, PDI of 0.214 ± 0.01 to 0.542 ± 0.08, and zeta potential of +31.6 ± 4.8 to +57.4 ± 12.5 mV were observed. Encapsulation efficiency was obtained in its maximum value (91.9 ± 16.2%) at the lowest drug/phospholipid ratio, median CTAB/phospholipid and the highest ethanol concentration. The optimized formulation was consisted of 0.3 as drug/lipid ratio, 1.25 as CTAB/lipid ratio and 30% ethanol concentration and showed responses' values in agreement with the predicted results. DSC studies suggested that EthoLeciplex existed in flexible state with complete incorporation of minoxidil into lipid bilayer. The cumulative amount of minoxidil permeated from EthoLeciplex, conventional liposome and ethanolic solution after 12h were 36.3 ± 1.5 µg/ml, 21 ± 2.0 µg/ml and 55 ± 4.0 µg/ml respectively. Based on the remaining amount, the amount of minoxidil accumulated in different skin layers can be predicted in descending order as follows; EthoLeciplex > conventional liposome > minoxidil solution. EthoLeciplex produced marked disorder in the stratum corneum integrity and swelling with no features of skin toxicity. This new cationic system is a promising carrier for cutaneous/transfollicular drug delivery.

The Unique Carboxymethyl Fenugreek Gum Gel Loaded Itraconazole Self-Emulsifying Nanovesicles for Topical Onychomycosis Treatment

The novel itraconazole (ITZ) nail penetration enhancing self-emulsifying nanovesicles (ITZ-nPEVs) loaded in carboxymethyl fenugreek gum (CMFG) gel circumvent the systemic onychomycosis treatment. The ITZ-nPEVs were prepared by the thin film hydration technique, and the particle size (PS), zeta potential (ZP), drug content (DC), entrapment efficiency (% EE), deformity index (DI), viscosity, morphology, and physical stability of the ITZ-nPEVs were measured. In terms of nail hydration, transungual drug absorption, and antifungal efficacy against Candida albicans, the chosen ITZ-nPEVs, nPEV-loaded CMFG (CMFG-ITZ-nPEVs) gel, and the commercialized Itrostred gel were compared. The ITZ-nPEVs showed spherical structure with high DC, % EE, low PS and PDI and positive ZP of ITZ ranging from 95.36 to 93.89 mg/5 mL and 95.36–96.94%, 196.55–252.5 nm, 0.092–0.49, and +11.1 to +22.5 mV, respectively. Compared to the Itrostred gel, the novel ITZ-nPEVs exhibited hydration enhancement factor for 24 h (HE24) of 1.53 and 1.39 drug uptake enhancement factor into nail clippings. Moreover, zone of inhibitions for ITZ-nPEVs (27.0 ± 0.25 mm) and CMFG-ITZ-nPEVs (33.2 ± 0.09 mm) against Candida albicans were significantly greater than that of Itrostred gel (22.9 ± 0.44 mm). For clinical investigation on onychomycotic patients, a nail penetration enhancer containing ITZ-nPEV-loaded CMFG gel presents a highly promising approach.

Poloxamer 407 Based Gel Formulations for Transungual Delivery of Hydrophobic Drugs: Selection and Optimization of Potential Additives

The current study aimed to develop poloxamer 407 (P407) gel for transungual delivery of antifungal hydrophobic drugs with sufficient gel strength and drug loading. Gel strength and drug loading of P407 gel was improved by use of functional additives. Hydration enhancement effect was used to select optimum nail penetration enhancer. Face-centered central composite design (FCCCD) was used to observe the effect of the selected penetration enhancer (thioglycolic acid (TGA)) and cosolvent (ethanol) on gelation behavior to develop formulation with enough loading of hydrophobic drug, i.e., terbinafine HCl (TBN), and its permeation across the nail plate without compromising on gel strength. It was observed that increasing concentration of P407 and TGA significantly reduced gelation temperature and enhanced the gel strength of P407 gel and can be used to improve P407 gel strength. Under the scanning electron microscope, the significant effect of TGA as an ungual penetration enhancer was observed on the morphology of the nail plate. Optimized P407 gel prepared with modified cold method showed a gelation temperature of 8.7 ± 0.16 °C, gel strength of 122 ± 7.5 s and drug loading of 1.2% w/w, which was four times more than the drug loading in the gels prepared with conventional cold method. Rheological behavior was pseudoplastic with 47.75 ± 3.48% of gel erosion after 12 washings and 67.21 ± 2.16% of drug release after 12 h. A cumulative amount of TBN permeated from P407 gel with and without PE after 24 h was 27.30 ± 4.18 and 16.69 ± 2.31 µg/cm², respectively. Thioglycolic acid can be used as a nail penetration enhancer without the chemical modification or addition of extra additives while retaining the gel strength. Water miscible cosolvents with moderate evaporability such as ethanol, can be incorporated to P407 gel by minor modification in method of preparation to load the required dose of hydrophobic drugs. Developed P407 gel formulation with sufficient gel strength and drug loading will be a promising carrier for transungual delivery of hydrophobic antifungal agents.

Onychomycosis: Current Understanding and Strategies for Enhancing Drug Delivery into Human Nail Tissue

BACKGROUND

Onychomycosis is by far the most common finger or toe nail fungal infectious disease caused by dermatophytes, non-dermatophytic molds or yeast. It accounts for 50% of the total nail disorders, and affects patients physically, socially, and psychologically and can seriously influence their quality of life.

OBJECTIVES

Oral antifungals are routinely used to treat the nail fungal disease; however oral therapy is associated with severe side effects and longer treatment times. In recent years, drug delivery directly into the nail or nail bed has gained attention and various topical products have been tested that can cure the disease when applied topically or transungually. Nevertheless, drug penetration into and through the nail is not straightforward and requires chemicals to improve its permeability or by applying physical stress to promote drug penetration into and through the nail. This lucid review presents an overview of various causes of onychomycosis, current therapeutic approaches, and efforts aimed at increasing the permeability of nails through various strategies such as chemical, physical and mechanical methods for permeation enhancement.

CONCLUSION

Various strategies have been proposed for the treatment of onychomycosis, however, much research into a more precise and effective therapy is still required.

Nanoliposome-loaded antifungal drugs for dermal administration: A review

Cutaneous fungal infections are the fourth most common health problem, which involves approximately one billion people worldwide. Drug delivery to the skin seems to be the best choice for superficial fungal infections. Topical formulations can release a sufficient amount of drug in therapeutical concentrations and permeate higher layers of the skin like the stratum corneum. As the outermost layer of the epidermis, the stratum corneum prevents the drug from penetrating the skin. Liposomes, especially nanosized as topical drug delivery systems to the skin, can show various functions depending on their size, lipids and cholesterol components, the percent of ingredients, lamellarity, and surface charge. Nanoliposomes can increase permeation through the stratum corneum, decrease systemic effects with their localizing actions, and overcome many dermal drug delivery obstacles. Antifungal drugs, such as croconazole, econazole, fluconazole, ketoconazole, terbinafine hydrochloride, tolnaftate, and miconazole entrapped in liposomes have indicated improved skin penetration and localizing effects. According to the literature review summarized in this paper, many studies have identified liposomes as a powerful carrier for topical antifungal drug delivery to the skin. However, a few studies introduced new generations of liposomes like ethosomes and transfersomes. This paper was conducted on almost all liposomal studies of antifungal drugs with dermal application.

The Potential of Caffeic Acid Lipid Nanoparticulate Systems for Skin Application: In Vitro Assays to Assess Delivery and Antioxidant Effect

The object of this study is a comparison between solid lipid nanoparticles and ethosomes for caffeic acid delivery through the skin. Caffeic acid is a potent antioxidant molecule whose cutaneous administration is hampered by its low solubility and scarce stability. In order to improve its therapeutic potential, caffeic acid has been encapsulated within solid lipid nanoparticles and ethosomes. The effect of lipid matrix has been evaluated on the morphology and size distribution of solid lipid nanoparticles and ethosomes loaded with caffeic acid. Particularly, morphology has been investigated by cryogenic transmission electron microscopy and small angle X-ray scattering, while mean diameters have been evaluated by photon correlation spectroscopy. The antioxidant power has been evaluated by the 2,2-diphenyl-1-picrylhydrazyl methodology. The influence of the type of nanoparticulate system on caffeic acid diffusion has been evaluated by Franz cells associated to the nylon membrane, while to evaluate caffeic acid permeation through the skin, an amperometric study has been conducted, which was based on a porcine skin-covered oxygen electrode. This apparatus allows measuring the O₂ concentration changes in the membrane induced by polyphenols and H₂O₂ reaction in the skin. The antioxidative reactions in the skin induced by caffeic acid administered by solid lipid nanoparticles or ethosomes have been evaluated. Franz cell results indicated that caffeic acid diffusion from ethosomes was 18-fold slower with respect to solid lipid nanoparticles. The amperometric method evidenced the transdermal delivery effect of ethosome, indicating an intense antioxidant activity of caffeic acid and a very low response in the case of SLN. Finally, an irritation patch test conducted on 20 human volunteers demonstrated that both ethosomes and solid lipid nanoparticles can be safely applied on the skin.

Polymeric Nanoparticle Versus Liposome Formulations: Comparative Physicochemical and Metabolomic Studies as L-Carnitine Delivery Systems

L-Carnitine has attracted much more attention especially in the treatment of crucial diseases such as diabetes, regional slimming, and obesity because of its metabolic activities. However, because of its short half-life, low bioavailability, and inability to be stored in the body, frequent dosing is required. In this study, L-carnitine-loaded liposome (lipo-carnitine) and PLGA nanoparticle (nano-carnitine) formulations were prepared and characterized. For lipo-carnitine and nano-carnitine formulations, particle size values were 97.88 ± 2.96 nm and 250.90 ± 6.15 nm; polydispersity index values were 0.35 ± 0.01 and 0.22 ± 0.03; zeta potential values were 6.36 ± 0.54 mV and - 32.80 ± 2.26 mV; and encapsulation efficiency percentage values were 14.26 ± 3.52% and 21.93 ± 4.17%, respectively. Comparative in vitro release studies of novel formulations and solution of L-carnitine revealed that L-carnitine released 90% of its content at the end of 1st hour. On the other hand, lipo-carnitine and nano-carnitine formulations maintained a controlled-release profile for 12 h. The in vitro efficacy of the formulations on cardiac fibroblasts (CFs) was evaluated by metabolomic studies and pathway analysis. Besides the prolonged release, lipo-carnitine/nano-carnitine formulations were also found to be effective on amino acid, carbohydrate, and lipid metabolisms. As a result, innovative nano-formulations were successfully developed as an alternative to conventional preparations which are available on the market.

Oleic Acid Vesicles for Transdermal Delivery of Propranolol Hydrochloride: Development and Characterization

Background:

Pharmaceutical scientists are exploring transdermal route for treatment of various systemic diseases nowadays. Transdermal nanocarrier systems show various advantages like bioavailability enhancement of drugs, avoidance of first pass hepatic metabolism, and reduction of dosing frequency of bioactive therapeutic molecules.

Objective:

The objective of the present research work was to encapsulate Propranolol hydrochloride into oleic acid vesicles and carry out in-vitro and in-vivo evaluation of oleic acid vesicular gel containing Propranolol hydrochloride.

Method:

Propranol hydrochloride loaded oleic acid vesicles were prepared by exploring thin film hydration method. Developed vesicles were evaluated for morphology, size, zeta potential and polydispersity index (PDI). Thermal behavior of drug loaded vesicles was checked using differential scanning calorimetry (DSC) and depth of skin penetration was determined using confocal laser scanning microscopy (CLSM). Oleic acid vesicles dispersed in Carbopol 934R gel were subjected to in-vivo evaluation in male Sprague Dawley rats through measurement of plasma concentration and tissue distribution of Propranolol hydrochloride.

Results:

Optimized formulation having oleic acid : Propranol hydrochloride in the ratio 7 : 3 showed highest entrapment (56.1 ± 0.7%), acceptable size (291.3 ± 2.2 nm), the optimum value of PDI (0.219 ± 0.043) and zeta potential (-27.13 ± 0.25 mV). The results of DSC analysis showed effective encapsulation of drug inside the vesicles and CLSM analysis revealed penetration of vesicles upto stratum spinosum layer of skin. The results of in-vivo study revealed capability of vesicular gel to prolong the release of Propranolol hydrochloride upto 24 h with a Cmax value of 83.6 ± 3.0 ng/mL which was higher compared to the marketed tablet of Propranolol hydrochloride [InderalR (40 mg), Abbott India Ltd.] (45.6 ± 3.1 ng/mL). Tissue distribution studies revealed higher percentage of Propranolol hydrochloride in various organs after 24 h of administration of vesicular gel compared to marketed tablet.

Conclusion:

Developed oleic acid vesicular gel could be effective to reduce dosing frequency and avoid side effects of oral Propranol hydrochloride.

Application of Chitosan-Encapsulated Orange Oil onto Footwear Insock Leathers : Spray drying technique for an environmentally sustainable antibacterial formulation

The purpose of this study was to devise an antibacterial treatment for footwear insock leathers. Orange oil-loaded chitosan microparticles were utilised for this purpose. Emulsion formulations with different ratios were prepared, and from these formulations microparticles were manufactured using a spray drying technique. Microparticles obtained in this way were applied to the insock leathers using a finishing process. Successful encapsulation was confirmed by ultraviolet-visible (UV-vis) spectrophotometry, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. The microparticles exhibited highly spheroid shape with a size range of 3‐5 μm. Microparticle encapsulation efficiencies ranged from 79.41% ± 3.36% to 86.60% ± 1.13%. After performing microbiological tests and in vitro release studies on the insock leathers, it was determined that the prepared microparticles are able to perform core material delivery. Also, successful microparticle application resulted in these leathers acquiring antibacterial properties. The products and process are biodegradable, nontoxic and biocompatible.

Design and Characterization of Ethosomes for Transdermal Delivery of Caffeic Acid

The present investigation describes a formulative study aimed at designing ethosomes for caffeic acid transdermal administration. Since caffeic acid is characterized by antioxidant potential but also high instability, its encapsulation appears to be an interesting strategy. Ethosomes were produced by adding water into a phosphatidylcholine ethanol solution under magnetic stirring. Size distribution and morphology of ethosome were investigated by photon correlation spectroscopy, small-angle X-ray spectroscopy, and cryogenic transmission electron microscopy, while the entrapment capacity of caffeic acid was evaluated by high-performance liquid chromatography. Caffeic acid stability in ethosome was compared to the stability of the molecule in water, determined by mass spectrometry. Ethosome dispersion was thickened by poloxamer 407, obtaining an ethosomal gel that was characterized for rheological behavior and deformability. Caffeic acid diffusion kinetics were determined by Franz cells, while its penetration through skin, as well as its antioxidant activity, were evaluated using a porcine skin membrane–covered biosensor based on oxygen electrode. Ethosome mean diameter was ≈200 nm and almost stable within three months. The entrapment of caffeic acid in ethosome dramatically prolonged drug stability with respect to the aqueous solution, being 77% w/w in ethosome after six months, while in water, an almost complete degradation occurred within one month. The addition of poloxamer slightly modified vesicle structure and size, while it decreased the vesicle deformability. Caffeic acid diffusion coefficients from ethosome and ethosome gel were, respectively, 137- and 33-fold lower with respect to the aqueous solution. At last, the caffeic acid permeation and antioxidant power of ethosome were more intense with respect to the simple solution.

Surface modified nanoliposome formulations provide sustained release for 5-FU and increase cytotoxicity on A431 cell line

Malignant melanoma is a type of skin cancer with high risk of metastasis. 5-Fluorouracil is commonly used for treatment of skin cancer, however its penetration through the skin is found to be insufficient in some cases. Therefore, we optimized its pharmacokinetics by fabricating 5- Fluorouracil-loaded nanoliposome formulations modified with Poly-L-lysine coating. 5-Fluorouracil-loaded nanoliposome formulations were prepared using dipalmitoylphosphatidylcholine, dicethylphosphate and cholesterol having encapsulation efficiency of 45 ± 9.61%. The particle size, zeta potential, polydispersity index and encapsulation rate of the prepared formulation was found to be 237.9 ± 0.986 nm, 41.4 ± 1.060 mV, 0.233 ± 0.019 and 88.2 ± 7.85%, respectively. Surface characterization, molecular structure and thermal property illumination of the formulations were performed alongside stability studies. The In-vitro release of 5-FU from Lipo-FU6 and PLL-1 formulations was investigated by dialysis membrane method. Within the first 12 hours, the percentage release of 5-FU from Lipo-FU6 and PLL-1 formulations was observed to be 47.17% and 20.84%, respectively. Moreover, the cytotoxicity study on A431 epidermal carcinoma cell lines has revealed that 5-FU-loaded formulations were toxic to cells unlike the 5-FU free formulations. In conclusion, PLL coated nanoliposome formulations showed a potential to be an effective option for further combined drug/gene therapy applications.

Co-delivery of terbinafine hydrochloride and urea with an in situ film-forming system for nail targeting treatment

Onychomycosis is a chronic nail disorder consisting of a fungal infection that causes physical and psychosocial discomfort to patients. However, its treatment remains challenging owing to the barrier of the highly keratinized nail plate and the short time that conventional formulations reside on nails. In this work, we developed an in situ film-forming system(IFFS) based on Eudragit® RLPO to co-deliver terbinafine hydrochloride (TBH) and urea, i.e., TBH-urea-RLPO IFFS, with the aim of overcoming the nail barrier, prolonging the residence time, and efficiently treating onychomycosis. The IFFS formulation formed a thin film with good appearance and adhesion upon application in situ. The physical states of TBH and urea in the film were evaluated with polarization microscopy and powder X-ray diffraction. TBH and urea were both amorphousmiscible components within the RLPO film. TBH release from TBH-urea-RLPO IFFS fitted to the Korsmeyer-Pappas model, and the cumulative release at 72 h was significantly higher than that from commercial preparations (Lamisil Pedisan® once). In vitro permeation of TBH from TBH-urea-RLPO IFFS through bovine hoof membranes was evaluated in comparison with the film containing TBH alone (TBH-RLPO) and commercial preparations. The retention and cumulative permeated amount of TBH were significantly enhanced for the TBH-urea-RLPO IFFS (170.80 ± 44.63 μg/cm²vs 75.49 ± 21.50 μg/cm²vs 60.25 ± 27.38 μg/cm²; 61.81 ± 16.09 μg/cm²vs 21.80 ± 11.56 μg/cm²vs 7.91 ± 1.03 μg/cm², respectively), and the membranes treated with different formulations were observed with SEM and FTIR to identify the denaturing effect of urea on bovine hoof keratin. In vitro antifungal tests against Trichophyton rubrum,Microsporum canis, Fusarium, and Aspergillus fumigatus were cultured on Muller-Hinton agar; the findings indicated that TBH-urea-RLPO IFFS enhanced TBH antifungal activity. Overall, the results support that TBH-urea-RLPO IFFS is an efficient and promising approach for onychomycosis targeting treatment.

Mechanistic Insights of Formulation Approaches for the Treatment of Nail Infection: Conventional and Novel Drug Delivery Approaches

Onychomycosis is a chronic disorder that is difficult to manage and hard to eradicate with perilous trends to relapse. Due to increased prevalence of HIV, use of immunosuppressant drugs and lifestyle-related factors, population affected with fungal infection of nail (Onychomycosis) happens to increase extensively in last two decades. Modalities available for the treatment of onychomycosis include systemically administered antifungals, mechanical procedures, and topical drug therapy. But the efficacy of the most of approaches to deliver drug at targeted site, i.e., deep-seated infected nail bed is limited due to compact and highly keratinized nail structure. A series of advanced formulation approaches, such as transfersomes, liposomes, nano/micro emulsion, nail lacquers etc., have been attempted to improve the drug penetration into nail plate more efficiently. The manuscript reviews these formulation approaches with their possible mechanisms by which they improve the drug penetration.Comparative analysis of available treatment modalities for onychomycosis has been provided with pros and cons of each alternatives. Additionally, ongoing research about the application of biological materials such as modified cationic antimicrobial peptides (AMPs), plant-derived proteins, and synthetic antimicrobial peptidomimetics have also been explored.

Topical Drug Delivery of Anti-infectives Employing Lipid-Based Nanocarriers: Dermatokinetics as an Important Tool

BACKGROUND

The therapeutic approaches for the management of topical infections have always been a difficult approach due to lack of efficacy of conventional topical formulations, high frequency of topical applications and non-patient compliance. The major challenge in the management of topical infections lies in antibiotic resistance which leads to severe complications and hospitalizations resulting in economic burden and high mortality rates.

METHODS

Topical delivery employing lipid-based carriers has been a promising strategy to overcome the challenges of poor skin permeation and retention along with large doses which need to be administered systemically. The use of lipid-based delivery systems is a promising strategy for the effective topical delivery of antibiotics and overcoming drug-resistant strains in the skin. The major systems include transfersomes, niosomes, ethosomes, solid lipid nanoparticles, nanostructured lipid carriers, microemulsion and nanoemulsion as the most promising drug delivery approaches to treat infectious disorders. The main advantages of these systems include lipid bilayer structure which mimics the cell membrane and can fuse with infectious microbes. The numerous advantages associated with nanocarriers like enhanced efficacy, improvement in bioavailability, controlled drug release and ability to target the desired infectious pathogen have made these carriers successful.

CONCLUSION

Despite the number of strides taken in the field of topical drug delivery in infectious diseases, it still requires extensive research efforts to have a better perspective of the factors that influence drug permeation along with the mechanism of action with regard to skin penetration and deposition. The final objective of the therapy is to provide a safe and effective therapeutic approach for the management of infectious diseases affecting topical sites leading to enhanced therapeutic efficacy and patient-compliance.

Novel Drug Delivery Strategies for the Treatment of Onychomycosis

Onychomycosis accounts for 50% of all nail disease cases and is commonly caused by dermatophytes. It was primarily considered a cosmetic problem but has been garnering attention lately due to its persistent nature and difficult treatment with relapses. With prolonged treatment duration and high cost involved in treating onychomycosis, several attempts have been made in overcoming the rigid nail barrier. The conventional treatment of onychomy-cosis involves oral and topical therapy. The oral antifungal agents though quite effective, are hepato-toxic and cause drug-drug interactions. Topical therapy is more patient compliant being devoid of such adverse effects but it suffers from another setback of improper nail penetration. Amorolfine and ciclopirox nail lacquers are popular market products. Since decades, efforts have been made to enhance topical delivery for efficiently treating ony-chomycosis. Mechanical, physical and chemical methods have been em-ployed. Despite all the attempts made, the nail delivery issues are far from be-ing solved. Recently, the focus has shifted to novel drug delivery systems like nanoparticles, microemulsions, polymeric films and nail lacquers for en-hanced drug permeation and localized therapy. The research around the world is exploring their potential as effective treatment options. This review intends to further explore the novel delivery strategies to treat a persistent fungal in-fection like onychomycosis.

Liposome-based combination therapy for acne treatment

Acne vulgaris is one of the most common chronic diseases worldwide with the high prevalence ratio of about 80-85% in patients who are in puberty period. For the treatment options, many conventional dosage forms are available; however, existing limitations of systemic administration of drugs (oral antibiotics), such as adverse events and resistance, led for seek of new formulation options. In this study, liposomes containing tetracycline HCl and tretinoin were prepared by the film formation method. In vitro characterization studies revealed that liposomes (111.10 ± 8.02 nm; P.D.I.=0.198 ± 0.03; Z.P.=25.83 ± 0.40 mV) with an encapsulation efficiency more than 80% for both APIs were formulated. In order to maintain a suitable viscosity for topical application, optimized liposomal formulations were dispersed in carbopol-based gel. In vitro release of APIs was sustained for 24 hours with released amounts of 56.44% and 58.44% for tetracycline HCl and tretinoin, respectively. Stability evaluation of both liposomes and liposomes in hydrogels was investigated for 6 months at 4 °C and 25 °C; and no statistically significant change was observed in terms of particle size, zeta potential, encapsulation efficiency, appearance, pH, and viscosity. Cytotoxicity tests confirmed the nontoxic structure of liposomal gel formulations on mice fibroblast cells. In addition, antibacterial efficacy has been proven with Staphylococcus aureus and Streptococcus epidermidis strains as well as the effect on biofilm formation and eradication. As a result, we hereby presented a new combination drug product, which consists of dual active ingredients having comedolytic and bacteriostatic effects in a single, safe, and stable liposome formulation.

Innovative nanocompounds for cutaneous administration of classical antifungal drugs: a systematic review

Nanomedicine manipulates materials at atomic, molecular, and supramolecular scale, with at least one dimension within the nanometer range, for biomedical applications. The resulting nanoparticles have been consistently shown beneficial effects for antifungal drugs delivery, overcoming the problems of low bioavailability and high toxicity of these drugs. Due to their unique features, namely the small mean particle size, nanoparticles contribute to the enhanced drug absorption and uptake by the target cells, potentiating the therapeutic drug effect. The topical route is desirable due to the adverse effects arising from oral administration. This review provides a comprehensive analysis of the use of nano compounds for the current treatment of topical fungal infections. A special emphasis is given to the employment of lipid nanoparticles, due to their recognized efficacy, versatility, and biocompatibility, attracting the major attention as novel topical nanocompounds used for the administration of antifungal drugs.

Potential of Chemical and Physical Enhancers for Transungual Delivery of Amorolfine Hydrochloride

Topical monotherapy of nail infection is limited by poor drug permeability into the human nail plate. Numerous substances and methods are applied to improve the antifungal agent delivery across the nail plate. This work aimed to evaluate the effect of chemical and physical enhancers on the accumulation and permeation of amorolfine hydrochloride through human nail clippings. Polymeric nail lacquers with Eudragit E100 were developed as a potentially suitable delivery system for amorolfine hydrochloride. Incorporating thioglycolic acid and urea into formulations provided increased accumulation of antifungal agent in nail layers of up to 100% and 57%, respectively. Structural changes of nail barrier, induced by fractional CO₂ laser, were visualized by microscopy. The permeation of amorolfine hydrochloride through the nail increased twofold when thioglycolic acid-containing formulation was applied and the nail was pretreated with a fractional CO₂ laser. The results suggest that this novel combination of enhancers has the potential to be an effective option for topical drug delivery through the nail, and increased the efficacy of treatment.

Polyurethanes as New Excipients in Nail Therapeutics

Onychomycosis affects about 15% of the population. This disease causes physical and psychosocial discomfort to infected patients. Topical treatment (creams, solutions, gels, colloidal carriers, and nail lacquers) is usually the most commonly required due to the high toxicity of oral drugs. Currently, the most common topical formulations (creams and lotions) present a low drug delivery to the nail infection. Nail lacquers appear to increase drug delivery and simultaneously improve the effectiveness of treatment with increased patient compliance. These formulations leave a polymer film on the nail plate after solvent evaporation. The duration of the film residence in the nail constitutes an important property of nail lacquer formulation. In this study, a polyurethane polymer was used to delivery antifungals drugs, such as terbinafine hydrochloride (TH) and ciclopirox olamine (CPX) and the influence of its concentration on the properties of nail lacquer formulations was assessed. The nail lacquer containing the lowest polymer concentration (10%) was the most effective regarding the in vitro release, permeation, and antifungal activity. It has also been demonstrated that the application of PU-based nail lacquer improves the nail plate, making it smooth and uniform and reduces the porosity contributing to the greater effectiveness of these vehicles. To conclude, the use of polyurethane in nail formulations is promising for nail therapeutics.

Preparation and Characterization of Caffeine Loaded Liposome and Ethosome Formulations for Transungual Application

Objectives

Nail plates have a structure that prevents transungual delivery of active agents. This situation makes it difficult to treat nail diseases.

Materials and Methods

In this study, CF-loaded liposome and ethosome formulations were prepared for ungual application. Formulations were characterized by size, microscopic observation, pH, and entrapment efficiency measurements. The effects of formulations and experimental conditions on nails were tested with characterization of nails before and after ex vivo permeation experiments.

Results

Microscopic observation confirmed the presence of spherical-structured vesicles. The particle sizes of vesicles were found as 545.3±0.121 nm, 610.2±0.943 nm, 349.5±0.145 nm and 337.9±0.088 nm for liposomes (FI-FII) and ethosomes (FIII- FIV), respectively. The polydispersity index of particles was found under 0.5, and the pH of formulations was around 7. The encapsulation efficiency was found low due to the hydrophilic character of CF. Nail characterization studies showed that the experimental conditions had an effect on the nail plate.

Conclusion

The cumulative amount of drug after ex vivo permeation studies was found higher for ethosomes than for liposomes. The results confirm that liposomal systems could be promising systems for ungual drug delivery.

Chemical and physical strategies in onychomycosis topical treatment: A review

Onychomycosis is a fungal infection of the fingernails or toenails caused by dermatophytes, nondermatophytes, moulds, and yeasts. This condition affects around 10-30% people worldwide, negatively influencing patients' quality of life, with severe outcomes in some cases. Since the nail unit acts as a barrier to exogenous substances, its physiological features hampers drug penetration, turning the onychomycosis treatment a challenge. Currently, there are several oral and topical therapies available; nevertheless, cure rates are still low and relapse rates achieves 10-53%. Also, serious side effects may be developed due to long-term treatment. In light of these facts, researchers have focused on improving topical treatments, either by modifying the vehicle or by using some physical technique to improve drug delivery trough the nail plate, hence increasing therapy effectiveness. Therefore, the aim of this paper is to explain these novel alternative approaches. First, the challenges for drug ungual penetration are presented. Then, the chemical and physical strategies developed for overcoming the barriers for drug penetration are discussed. We hope that the information gathered may be useful for the development of safer and more effective treatments for onychomycosis.

Optimized Ciclopirox-Based Eudragit RLPO Nail Lacquer: Effect of Endopeptidase Enzyme as Permeation Enhancer on Transungual Drug Delivery and Efficiency Against Onychomycosis

The aims of our investigation were to develop and optimize ciclopirox (CPX) nail lacquer using nonbiodegradable Eudragit RLPO (E-RLPO) as a film former and to assess its penetration efficiency across the human nail plate. Preliminary trials such as hydration enhancement factor (HEF), a retained drug in the nail plate, and SEM were studied to select the optimized permeation enhancer to be incorporated in the optimized lacquer formulation. A 3³ full factorial design was built up to study the effect of three different factors, concentration of E-RLPO (10, 20, and 30%), Tween 80 (0.25, 0.5, and 1%), and triacetin (0, 10, and 30% of polymer weight). The studied responses were the drying time, water resistance, viscosity, and drug release up to 4 h. An ex vivo permeation study for the optimized formulations was carried out. The preliminary study aided the selection of 5% papain (endopeptidase enzyme) as a penetration enhancer; it showed the highest HEF of 15.27%, the highest amount of drug retained in the nail plate (886.2 μg/g). An ex vivo permeation study guided the selection of F4B (flux value of 3.79 μg/cm²/h) as optimized formulation. The optimized lacquer formula showed threefold increases in the permeation than the marketed CPX lacquer (Batrafen®). Confocal laser scanning microscopy revealed the higher intensity of the Rhodamine B dye across the nail plate in the case of the formula containing papain than the marketed formula without papain. Conclusively, an efficient and stable nail lacquer was developed for potential transungual delivery of CPX to target the drug to the nail bed and ensure efficiency against onychomycosis.

A novel transdermal nanoethosomal gel of betahistine dihydrochloride for weight gain control: in-vitro and in-vivo characterization

Background

Betahistine dihydrochloride (BDH) is a histamine analog used to control weight gain, with short elimination half-life and gastric irritation as side effects.

Objective

The aim of the current investigation is to formulate and optimize a topical BDH ethosomal gel for weight gain control.

Materials and methods

Box–Behnken design was applied to study the effect of independent variables: phosphatidylcholine (PC), propylene glycol (PG), and ethanol on vesicle size; entrapment efficiency; % drug release; and flux. The morphology and zeta potential of the optimized formulation were evaluated. The % drug release, flux, and pharmacodynamics of the optimized formulation gel were studied.

Results

The size and entrapment efficiency percent had a direct positive relationship with the concentration of PC and negative relationship with ethanol and PG. The % drug release and flux decreased with increasing PC and PG, while ethanol enhanced both responses. Regression modeling indicated a good correlation between dependent and independent variables, where F16 was chosen as the optimized formulation. F16 showed well-defined spherical vesicles and zeta potential of −24 mV, and % release from the gel exceeded 99.5% over 16 h with the flux of 0.28 mg/cm²/h. Food intake and weight gain of rats were significantly decreased after transdermal application of the BDH ethosomal gel when compared with control, placebo, and BDH gel. The histopathological findings proved the absence of inflammation and decrease in adipose tissue.

Conclusion

Results obtained showed a significant, sustained transdermal absorption of BDH ethosomal gel and, consequently, a decrease in food intake and weight gain.

Dual-Prevention for UV-Induced Skin Damage: Incorporation of Melatonin-Loaded Elastic Niosomes into Octyl Methoxycinnamate Pickering Emulsions

Incorporation of antioxidants into sunscreens is a logical approach, yet co-delivery of them with UV filters is a challenge. Here, we purposed a combination therapy, in which the chemical UV filter, octyl methoxycinnamate, was accumulated on upper skin while the antioxidant, melatonin, can penetrate deeper layers to show its effects. Melatonin-loaded elastic niosomes and octyl methoxycinnamate Pickering emulsion were prepared separately. Lyophilized elastic niosomes were dispersed into the Pickering emulsion to prepare the proposed combination formulation. The characterization studies of the formulations revealed that elastic niosomes can be prepared with tunable nanometer sizes, whereas Pickering emulsions can encapsulate the UV filter in micrometer-sized droplets. Melatonin-loaded elastic niosomes prepared with Tween80/Span80 mixture were 146 nm with a PI of 0.438, and 58.42% entrapment efficiency was achieved. The mean diameter size of the combination formulation was 27.8 μm. Ex vivo permeation studies revealed that 7.40% of octyl methoxycinnamate and 58% of melatonin were permeated through the rat skin while 27.6% octyl methoxycinnamate and 37% of melatonin accumulated in the skin after 24 h. Cell culture studies with real-time cell analyzer showed that the proposed formulation consist of melatonin-loaded elastic niosomes and octyl methoxycinnamate Pickering emulsion had no negative effect on the cell proliferation and viability. According to α,α-diphenyl-β-picrylhydrazyl free radical scavenging method, the proposed formulation showed as high antioxidant activity as melatonin itself. It is concluded that the proposed formulation would be a promising dual therapy for UV-induced skin damage with co-delivery strategy.

Development and evaluation of finasteride loaded ethosomes for targeting to the pilosebaceous unit

Androgenetic alopecia, a major cause for baldness, is caused by the deposition of dihydrotestosterone (DHT) at the androgen receptors present in the pilosebaceous unit (PSU). Finasteride (FIN) is a potent 5α-reductase inhibitor capable of preventing the conversion of testosterone to DHT. But, its oral administration in males causes infertility. An attempt was made to prepare ethosomes of FIN with a size range 100-300 nm to enhance its delivery to the PSU. Finasteride loaded ethosomes (FES) were prepared using an ultra-probe sonicator and characterized for its size, morphology, surface charge and entrapment efficiency. The ability of FES to permeate across rat skin and frontal scalp skin of human cadaver was also evaluated. The spherical shaped ethosomes of different batches were in the size range of 107.8 ± 2.50 to 220.4 ± 6.92 nm and showed good permeation across rat skin and frontal scalp skin of human cadaver when compared to the unencapsulated FIN. The results portrayed the ability of FES to permeate across the stratum corneum to reach the PSU of the hair follicle. Although additional use of permeation enhancer increases the permeation of FIN across the skin, its addition may not be a favourable option for the deposition of ethosomes in the PSU.

In Vitro Antifungal Activity of Hexahydropyrimidine Derivatives against the Causative Agents of Dermatomycosis

Nitrogenated heterocyclic compounds are present in both natural and synthetic drugs, and hexahydropyrimidine derivatives may prove to be efficient in treating dermatomycosis causing fungi. This study evaluated the antifungal activity of four hexahydropyrimidine derivatives against the dermatomycosis causing fungi. These derivatives were synthesized, characterized, and assessed in terms of their activity against Trichophyton mentagrophytes, Microsporum canis, Microsporum gypseum, Trichophyton rubrum, Fusarium oxysporum, and Epidermophyton floccosum between concentrations 7.8 and 1,000 μg mL⁻¹. Scanning electron micrographs were assessed for the active derivatives and reference drugs, and these micrographs revealed that new agents cause morphological changes in fungi. The derivatives HHP1, HHP3, and HHP4 revealed poor activity against the four fungal strains (MICs range 500–1000 μg mL⁻¹). Compound HHP3 was found to be the best potential antifungal agent among those tested and was the most effective among all the active derivatives that caused morphological changes in the susceptible strains.

Voriconazole-loaded nanostructured lipid carriers (NLC) for drug delivery in deeper regions of the nail plate

Voriconazole-loaded nanostructured lipid carriers (VOR-NLC) were developed and drug penetration evaluated in porcine hooves in vitro. Synergistic effect of urea (Ur), selected among other known chemical enhancers according to hoof hydration potential, was also evaluated. VOR-NLC presented a high encapsulation efficiency (74.52±2.13%), approximate mean diameter of 230nm and were positively charged (+27.32±2.74mV). Stability studies indicated they were stable under refrigeration (4±2°C) for up to 150days. SEM images revealed hooves treated with VOR-NLC and VOR-NLC-Ur suffered a disturbance on the surface depicting high roughness and porosity. Permeation data showed a substantial VOR amount retained in superficial hooves sections independent of the formulation used (2.42±0.26; 2.52±0.36 and 2.41±0.60μg/cm² for unloaded VOR, VOR-NLC and VOR-NLC-Ur, respectively, p>0.05). Still, successive extractions, revealed the amount of VOR retained in deeper regions was significantly higher when VOR-NLC or VOR-NLC-Ur was used (0.17±0.04, 0.47±0.14 and 0.36±0.07μg/cm² for unloaded VOR, VOR-NLC and VOR-NLC-Ur, respectively, p<0.05). Such results indicate NLC are promising formulations for the management of onychomycosis. Further studies in diseased nail plates are necessary.

Terbinafine Hydrochloride Trans-ungual Delivery via Nanovesicular Systems: In Vitro Characterization and Ex Vivo Evaluation

Treating a nail infection like onychomycosis is challenging as the human nail plate acts as a formidable barrier against all drug permeation. Available oral and topical treatments have several setbacks. Terbinafine hydrochloride (TBH), belonging to the allylamine class, is mainly used for treatment of onychomycosis. This study aims to formulate TBH in a nanobased spanlastic vesicular carrier that enables and enhances the drug delivery through the nail. The nanovesicles were formulated by ethanol injection method, using either Span® 60 or Span® 65, together with Tween 80 or sodium deoxycholate as an edge activator. A full factorial design was implemented to study the effect of different formulation and process variables on the prepared TBH-loaded spanlastic nanovesicles. TBH entrapment efficiency percentages, particle size diameter, percentage drug released after 2 h and 8 h were selected as dependent variables. Optimization was performed using Design-Expert® software to obtain an optimized formulation with high entrapment efficiency (62.35 ± 8.91%), average particle size of 438.45 ± 70.5 nm, and 29.57 ± 0.93 and 59.53 ± 1.73% TBH released after 2 and 8 h, respectively. The optimized formula was evaluated using differential scanning calorimetry and X-ray diffraction and was also morphologically examined using transmission electron microscopy. An ex vivo study was conducted to determine the permeation and retainment of the optimized formulation in a human cadaver nail plate, and confocal laser scanning microscope was used to show the extent of formulation permeation. In conclusion, the results confirmed that spanlastics exhibit promising results for the trans-ungual delivery of TBH.

Effect of Film-Forming Polymers on Release of Naftifine Hydrochloride from Nail Lacquers

The successful topical therapy of onychomycosis depends on effective drug release and penetration into nail, which can be achieved by using an adequately developed delivery system. This study evaluated and compared effect of film-forming polymers Eudragit RL100, Eudragit RS100, and ethyl cellulose on naftifine hydrochloride release from experimental nail lacquer formulations. Quality of formulations was evaluated by determining drying time and water resistance. Interactions between active pharmaceutical ingredient and excipients were investigated using microcalorimetry and FT-IR. Optimization of nail lacquer formulations was performed by naftifine hydrochloride release testing. Release of naftifine hydrochloride increased with increasing concentration of Eudragit RL100. Plasticizer triacetin affected the release of naftifine hydrochloride, when Eudragit RS100 polymer was used. Ethyl cellulose polymer was determined to be not applicable for naftifine hydrochloride nail lacquer formulations. Two compositions of nail lacquers were optimized and could be used in further development of transungual delivery systems.

[Antifungal Activity of Luliconazole Nail Solution on in vitro and in vivo Onychomycosis Model]

We evaluated luliconazole nail solution, originally generated formulation, for the topical treatment of onychomycosis by two infection models. First, a suspension of Trichophyton mentagrophytes was dropped onto the ventral layer of human nail plate and these nails were set in Franz diffusion cells. After 9-day culture, luliconazole nail solutions (1, 3, and 5%) were applied to the dorsal surface of the nails once a day for 7 days. After application, fungal viability was assessed by measuring the ATP contents of the samples. The dose-dependent efficacy was confirmed, with 3% and 5% luliconazole nail solutions producing significantly lower ATP levels at 7-day treatment. When 3% and 5% luliconazole nail solutions were evaluated in a rabbit model of onychomycosis, both concentrations completely inhibited the recovery of fungi on culture after 4-week treatment. We therefore think these results indicate that 5% luliconazole nail solution is sufficiently potent for treatment of onychomycosis.

Bio-based topical system for enhanced salicylic acid delivery: preparation and performance of gels

Objectives

New salicylic acid (SA)-loaded gels were developed using excipients made from renewable materials, and our goal was to improve drug permeation in the topical treatment of acne vulgaris.

Methods

We studied the preparation parameters to obtain suitable gel formulations. Only naturally occurring polymers were used as gelling agents. Two hydrogels and three lipogels were selected and characterized in terms of drug loading, pH, viability cells, rheology, mechanical properties and in vitro permeation; these hydrogels and lipogels were compared with the traditional ointment. We also evaluated skin parameters before and after gel application.

Key findings

The formulations that we studied are non-Newtonian fluids; they have high drug loading and suitable mechanical properties. Lipogels exhibit a slower and more linear in vitro permeation profile compared with hydrogels. The different vehicles that we used affected drug permeation and improve patient compliance. Cytotoxicity studies suggest that all of the formulations are non-toxic.

Conclusions

Lipogels demonstrate appropriate technological features and improved performance compared with the traditional ointment with regard to their composition. Lipogels may represent a new bio-based topical system for SA delivery. The use of ‘green’ excipients leads to ‘skin-friendly’ formulations that are able to satisfy environmental safety.

Iontophoresis for drug delivery into the nail apparatus: exploring hyponychium as the site of delivery

In present studies, a hyponychium pathway (from ventral side of the nail plate) was investigated as a potential route of drug delivery into the nail apparatus using iontophoresis as an active physical method. In vitro transport studies were performed across the human nail plate using sodium fluorescein as a marker substrate for 24 h. After transport studies, the amount of sodium fluorescein extracted from an active diffusion area of the nail plate in case of iontophoresis was found to be ∼54-folds more to that of passive. The amount of sodium fluorescein retained in the peripheral area of the nail plate after application of iontophoresis was found to be ∼30-folds more relative to passive. Ex vivo transport studies were performed on excised human cadaver toe using terbinafine hydrochloride as a model drug for three days (8 h/day). The amount of terbinafine retained in the nail plate after application of iontophoresis (3.43 ± 1.34 µg/mg) was ∼20-folds more when compared with passive (0.17 ± 0.10 µg/mg). The amount of drug extracted from the nail bed and nail matrix was 1.73 ± 0.12 µg/mg and 0.55 ± 0.22 µg/mg, respectively. On the other hand, there was no detectable amount of terbinafine found in the nail bed and nail matrix in case of control (passive delivery). These studies show that the iontophoretic drug delivery through hyponychium region to other parts of the nail apparatus could be a potential way of onychomycosis treatment.

Onychomycosis: Potential of Nail Lacquers in Transungual Delivery of Antifungals

Onychomycosis constitutes the most common fungal infection of the nail (skin beneath the nail bed) that affects the finger as well as toe nails. It is an infection that is initiated by yeasts, dermatophytes, and nondermatophyte molds. Nail lacquers are topical solutions intended only for use on fingernails as well as toenails and have been found to be useful in the treatment of onychomycosis. Thus, in the present review an attempt has been made to focus on the treatment aspects of onychomycosis and the ungual delivery of antifungals via nail lacquer. Several patents issued on nail lacquer till date have also been discussed. Penetration efficiency was assessed by several researchers across the human nail plate to investigate the potentiality of nail lacquer based formulations. Various clinical trials have also been conducted in order to evaluate the safety and efficacy of nail lacquers in delivering antifungal agents. Thus, it can be concluded that nail lacquer based preparations are efficacious and stable formulations. These possess tremendous potential for clinical topical application to the nail bed in the treatment of onychomycosis.

In vitro assessment of pharmaceutical potential of ethosomes entrapped with terbinafine hydrochloride

The present study investigates the entrapment of terbinafine hydrochloride (TH) in ethosomal vesicles via unsonicated and sonication method. Carbopol 934P was incorporated in the best formulation, F6, obtained by sonication method. The formulated ethosomal gel obtained as such i.e. F6(∗) was exploited to achieve a zero order release profile of TH. The composition includes phospholipid, ethanol and propylene glycol. Drug entrapment efficiency (DEE), in-vitro and ex-vivo drug diffusion studies, FT-IR and stability studies of the prepared ethosomes were investigated. The size and shape of F6 ethosomes vesicles were characterized by SEM. In-vitro drug release studies were performed using sigma dialysis membrane in phosphate buffer, pH 7.4 for 12 h while drug content was determined by HPLC. DEE was ranked from 55.33 ± 1.32% to 69.11 ± 2.11%. Highest DEE was seen with F6 ethosomal formulation with a vesicle size of 248 ± 1.02 nm. FT-IR studies confirmed that there was no chemical interaction between drug and excipients used in the formulation. Ex-vivo result suggested that drug diffusion observed after 12 h from F6(∗) and marketed cream (MR) formulations was 74.01 ± 0.62% and 61.45 ± 0.86%, respectively. The results of similarity factor (f 2 values) for MR and F6(∗) ethosomal gel were 85.14 and 42.63, respectively. It revealed that F6(∗) showed dissimilar dissolution profiles. Transdermal flux value for F6(∗) and MR was found to be 144.61 ± 1.28 μg/cm(2)/h and 121.6 ± 1.16 μg/cm(2)/h, respectively. This study disclosed that F6(∗) resides at targeted site for a relatively longer period of time thereby signifying the improved patient compliance.

Novel nail penetration enhancer containing vesicles "nPEVs" for treatment of onychomycosis

CONTEXT

The systemic treatment of onychomycosis has been hampered by the reported side effects of antifungals in addition to the limited blood circulation to the affected nails. Topical ungual treatment would circumvent the limitations of systemic onychomycosis treatment.

OBJECTIVE

Preparation and characterization of nail penetration enhancer containing nanovesicles (nPEVs) loaded with sertaconazole for topical treatment of onychomycosis.

MATERIALS AND METHODS

nPEVs were prepared using different nail penetration enhancers (N-acetyl-L-cysteine, thioglycolic acid, thiourea and ethanol) by the thin film hydration method, and characterized for their particle size, zeta potential, entrapment efficiency (EE%), elasticity, viscosity, physical stability and morphology. The selected nPEVs formula and the marketed Dermofix® cream were compared in terms of nail hydration, transungual drug uptake and antifungal activity against Trichophyton rubrum.

RESULTS

N-acetyl-l-cysteine was the optimum nail penetration enhancer for incorporation within vesicles. nPEVs showed high EE% of sertaconazole ranging from 77 to 95%, a size ranging from 38-538 nm and a zeta potential ranging from +48 to +72 mV. The selected nPEVs formula displayed spherical morphology and good storage stability. Compared to the conventional marketed cream, the selected nPEVs formula showed 1.4-folds higher hydration and drug uptake enhancement into nail clippings. Furthermore, it showed significantly higher zone of inhibition for Trichophyton rubrum (20.9 ± 0.25 mm) than the marketed cream (11.6 ± 0.44 mm).

CONCLUSION

Nail penetration enhancer containing nanovesicles (nPEVs) present a very promising option, worthy of clinical experimentation on onychomycotic patients.