Development of Miconazole-Loaded Microemulsions for Enhanced Topical Delivery and Non-Destructive Analysis by Near-Infrared Spectroscopy

The antifungal drug miconazole nitrate has a low solubility in water, leading to reduced therapeutic efficacy. To address this limitation, miconazole-loaded microemulsions were developed and assessed for topical skin delivery, prepared through spontaneous emulsification with oleic acid and water. The surfactant phase included a mixture of polyoxyethylene sorbitan monooleate (PSM) and various cosurfactants (ethanol, 2-(2-ethoxyethoxy) ethanol, or 2-propanol). The optimal miconazole-loaded microemulsion containing PSM and ethanol at a ratio of 1:1 showed a mean cumulative drug permeation of 87.6 ± 5.8 μg/cm² across pig skin. The formulation exhibited higher cumulative permeation, permeation flux, and drug deposition than conventional cream and significantly increased the in vitro inhibition of Candida albicans compared with cream (p < 0.05). Over the course of a 3-month study conducted at a temperature of 30 ± 2 °C, the microemulsion exhibited favorable physicochemical stability. This outcome signifies its potential suitability as a carrier for effectively administering miconazole through topical administration. Additionally, a non-destructive technique employing near-infrared spectroscopy coupled with a partial least-squares regression (PLSR) model was developed to quantitatively analyze microemulsions containing miconazole nitrate. This approach eliminates the need for sample preparation. The optimal PLSR model was derived by utilizing orthogonal signal correction pretreated data with one latent factor. This model exhibited a remarkable R² value of 0.9919 and a root mean square error of calibration of 0.0488. Consequently, this methodology holds potential for effectively monitoring the quantity of miconazole nitrate in various formulations, including both conventional and innovative ones.

10-Hydroxy Decanoic Acid-Based Vesicles as a Novel Topical Delivery System: Would It Be a Better Platform Than Conventional Oleic Acid Ufasomes for Skin Cancer Treatment?

10-hydroxy decanoic acid (HDA), a naturally derived fatty acid, was used for the preparation of novel fatty acid vesicles for comparison with oleic acid (OA) ufasomes. The vesicles were loaded with magnolol (Mag), a potential natural drug for skin cancer. Different formulations were prepared using the thin film hydration method and were statistically evaluated according to a Box-Behnken design in terms of particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE). The ex vivo skin permeation and deposition were assessed for Mag skin delivery. In vivo, an assessment of the optimized formulae using 7,12-dimethylbenz[a]anthracene (DMBA)-induced skin cancer in mice was also conducted. The PS and ZP of the optimized OA vesicles were 358.9 ± 3.2 nm and -82.50 ± 7.13 mV compared to 191.9 ± 6.28 nm and -59.60 ± 3.07 mV for HDA vesicles, respectively. The EE was high (>78%) for both types of vesicles. Ex vivo permeation studies revealed enhanced Mag permeation from all optimized formulations compared to a drug suspension. Skin deposition demonstrated that HDA-based vesicles provided the highest drug retention. In vivo, studies confirmed the superiority of HDA-based formulations in attenuating DMBA-induced skin cancer during treatment and prophylactic studies.

The significance of quercetin-loaded advanced nanoformulations for the management of diabetic wounds

Quercetin is a well-known plant flavanol that exhibits multiple biological activities, including antioxidant, anti-inflammatory and anticancer activities. The role of quercetin in wound healing has been widely explored by a range of researchers in different models. However, the physicochemical properties, such as solubility and permeability, of this compound are low, which ultimately limits its bioavailability on the target site. To overcome these limitations for successful therapy, scientists have developed a range of nanoformulations that provide effective therapeutic potential. In this review, the broad mechanism of quercetin for acute and chronic wounds is covered. A compilation of recent advances on the horizon of wound healing via quercetin is incorporated with several advanced nanoformulations.

Gellan gum spongy-like hydrogel-based dual antibiotic therapy for infected diabetic wounds

Diabetic foot infection (DFI) is an important cause of morbidity and mortality. Antibiotics are fundamental for treating DFI, although bacterial biofilm formation and associated pathophysiology can reduce their effectiveness. Additionally, antibiotics are often associated with adverse reactions. Hence, improved antibiotic therapies are required for safer and effective DFI management. On this regard, drug delivery systems (DDSs) constitute a promising strategy. We propose a gellan gum (GG)-based spongy-like hydrogel as a topical and controlled DDS of vancomycin and clindamycin, for an improved dual antibiotic therapy against methicillin-resistant Staphylococcus aureus (MRSA) in DFI. The developed DDS presents suitable features for topical application, while promoting the controlled release of both antibiotics, resulting in a significant reduction of in vitro antibiotic-associated cytotoxicity without compromising antibacterial activity. The therapeutic potential of this DDS was further corroborated in vivo, in a diabetic mouse model of MRSA-infected wounds. A single DDS administration allowed a significant bacterial burden reduction in a short period of time, without exacerbating host inflammatory response. Taken together, these results suggest that the proposed DDS represents a promising strategy for the topical treatment of DFI, potentially overcoming limitations associated with systemic antibiotic administration and minimizing the frequency of administration.

Plaster Gel Loaded with Silver Nanoparticle-Mediated Ganoderma applanatum: from Fabrication to Evaluation

Traditional Asian remedies have mainly employed the macrofungus Ganoderma applanatum, which belongs to the family Ganodermataceae, as a medicinal mushroom due to its high antibacterial and antioxidant activity. Extracts of the fungus can be synthesized into nanoparticles, which are subsequently produced as plaster gels. Synthesized silver nanoparticle-mediated G. applanatum was discovered to have the greatest ability to inhibit bacterial growth in S. epidermidis. When applied to the skin, the prepared plaster gel converted from a gel to a film; thus, both gel and film generation are characteristic of its formulation. The plaster gel that was made was found to be consistent and attractive, and the yellow color had darkened. Its viscosity and pH were appropriate for the application and allowed it to remain on the skin without dripping or reacting with the skin until it dried. A shorter duration for film formation is possible. The film's tensile was slightly reduced, and it exhibited excellent thermal stability. Decomposition of the generated film occurred at a slower rate, which constrained the polymer chain's ability to move. The semi-crystalline structure was characteristic of the film. It was found that particles were distributed in the film. Rapid release from plaster gel within 4 h was seen, and this was followed by a period of a slowly declining release rate over 12 h. The accurate first-order kinetic used to estimate the release rate of the formulation. The plaster gel demonstrated greater antibacterial activity than the MIC value indicated. The in vivo evaluation was positive and showed no skin irritation. The formulation showed good stability. Therefore, this indicated that the prepared plaster gel is appropriate for topical pharmaceutical delivery and safe for skin application.

Skin penetration of caffeine from commercial eye creams and eye creams designed and optimized based on Hansen Solubility Parameters

Computer-aided formulation design can streamline and speed up product development. In this study, ingredient screening and optimizing software, Formulating for Efficacy® (FFE), was used to design and optimize creams for the topical delivery of caffeine. FFE was set up to optimize lipophilic active ingredients, therefore, this study challenged the program's capabilities. The effect of two chemical penetration enhancers, including dimethyl isosorbide (DMI) and ethoxydiglycol (EDG), were studied based on their favorable Hansen Solubility Parameter physicochemical input parameters for the skin delivery of caffeine in the FFE® software application. Four oil-in-water emulsions containing 2% caffeine were formulated, one without a chemical penetration enhancer, one with five percent of DMI, one with five percent of EDG, and one with 2.5% of DMI and EDG each (DMI+EDG). Additionally, three commercial products were used as reference products. The cumulative amount of caffeine released and permeated, and the flux across Strat-M® membranes were determined using Franz diffusion cells. The eye creams had skin-compatible pH, excellent spreadability for the application area, were opaque emulsions with 14-17 μm droplet size, and were stable at 25 °C for 6 months. All four eye creams formulated released over 85% of caffeine in 24 hours, outperforming the commercial products. DMI+EDG cream provided the highest permeation in vitro in 24 hours, which was significantly higher than the commercial products (p < 0.05). FFE proved to be a valuable and quick tool to aid in the topical delivery of caffeine.

Kojic Acid and Kojic Acid Ester: Review on Nanotechnology-based Approach for Enhancing the Delivery Efficacy

Kojic acid (KA), a fungal secondary metabolite, is commonly used in the cosmetic industry as a skin-whitening agent because of its ability to inhibit tyrosinase, the enzyme involved in melanin production. However, KA has shown poor depigmenting effects and becomes unstable after prolonged storage. Its use in cosmetics products has also been restricted due to its hydrophilic nature. To overcome these limitations, the structure of KA can be altered to form KA derivatives, such as KA ester (KAE), with improved chemical and biological properties. For instance, multiple studies have shown that KAE is more effective at inhibiting tyrosinase, is less toxic and more stable than KA, thus making it more beneficial. Aside from structural modification, nanotechnology applications such as nanoemulsion, and others have shown the ability to strengthen the efficacy of both KA and KAE by increasing skin permeability and delivering the drug more precisely to the targeted site with better controlled release rate. Therefore, the aim of this review article is to discuss the importance of modifying KA's chemical structure as well as the role of nanoemulsion, solid lipid nanoparticles (SLN), nanostructured lipid carrier (NLC), liposomes and ethosomes in improving topical delivery of KA and KAE for cosmetic and pharmaceutical applications.

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

OBJECTIVE

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

SIGNIFICANCE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Topical Delivery of ROS-Responsive Methotrexate Prodrug Nanoassemblies by a Dissolvable Microneedle Patch for Psoriasis Therapy

Purpose

Oxidative stress, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and adenosine signaling are factors associated with psoriatic inflammation. Topical delivery of methotrexate (MTX) has become an option to overcome the side effects caused by systemic therapy in psoriasis, leading to the suppression of NF-κB activation through boosting adenosine release. However, thickened psoriatic skin is the primary restriction against local drug delivery.

Methods

In this study, a ROS responsive MTX prodrug (MTX-TK-HA) was synthesized with the feature of CD44 mediated active targeting to hyperproliferative keratinocytes. MTX prodrug and PLA-mPEG were formulated by nano-precipitation method to develop the MTX-TK-HA/PLA-mPEG nanoassemblies. To achieve painless transdermal delivery, a dissolving microneedle was applied for direct loading of these nanoassemblies by micromolding technique. The particle size, zeta potential, ROS-responsiveness, permeability, and mechanical strength of nanoassemblies and microneedle arrays were determined, respectively. Then, MTT assay, immunoblot analysis, ELISA assay, flow cytometry, and histological staining were utilized to thoroughly evaluate the efficacy of nanoassemblies-loaded microneedles in an imiquimod-induced psoriatic mouse model.

Results

Nanoassemblies-loaded microneedle arrays were capable of significantly penetrating imiquimod-induced psoriatic epidermis in mice. The efficient topical delivery of these nanoassemblies was achieved by potent mechanical strength and hyaluronic acid as the dissolvable matrix for microneedle arrays. CD44-mediated endocytosis enabled the intracellular uptake of nanoassemblies in keratinocytes, and methotrexate was released from MTX-TK-HA with ROS stimuli, followed by suppressing the proliferation of epidermal cells via NF-κB pathway blockade.

Conclusion

In a psoriatic mouse model, nanoassemblies loaded microneedle arrays relieve inflammatory skin disorders via regulation of adenosine and NF-κB signaling. Our study offered a rational design for the transdermal delivery of hydrophobic agents and defined an effective therapeutic option for psoriasis treatment.

Polymeric Nanoparticles as Tunable Nanocarriers for Targeted Delivery of Drugs to Skin Tissues for Treatment of Topical Skin Diseases

The topical route is the most appropriate route for the targeted delivery of drugs to skin tissues for the treatment of local skin diseases; however, the stratum corneum (SC), the foremost layer of the skin, acts as a major barrier. Numerous passive and active drug delivery techniques have been exploited to overcome this barrier; however, these modalities are associated with several detrimental effects which restrict their clinical applicability. Alternatively, nanotechnology-aided interventions have been extensively investigated for the topical administration of a wide range of therapeutics. In this review, we have mainly focused on the biopharmaceutical significance of polymeric nanoparticles (PNPs) (made from natural polymers) for the treatment of various topical skin diseases such as psoriasis, atopic dermatitis (AD), skin infection, skin cancer, acute-to-chronic wounds, and acne. The encapsulation of drug(s) into the inner core or adsorption onto the shell of PNPs has shown a marked improvement in their physicochemical properties, avoiding premature degradation and controlling the release kinetics, permeation through the SC, and retention in the skin layers. Furthermore, functionalization techniques such as PEGylation, conjugation with targeting ligand, and pH/thermo-responsiveness have shown further success in optimizing the therapeutic efficacy of PNPs for the treatment of skin diseases. Despite enormous progress in the development of PNPs, their clinical translation is still lacking, which could be a potential future perspective for researchers working in this field.

Macrocyclic Retinoic Acid Receptor-Related Orphan Receptor C2 Inverse Agonists

Macrocyclic retinoic acid receptor-related orphan receptor C2 (RORC2) inverse agonists have been designed with favorable properties for topical administration. Inspired by the unanticipated bound conformation of an acyclic sulfonamide-based RORC2 ligand from cocrystal structure analysis, macrocyclic linker connections between the halves of the molecule were explored. Further optimization of analogues was accomplished to maximize potency and refine physiochemical properties (MW, lipophilicity) best suited for topical application. Compound 14 demonstrated potent inhibition of interleukin-17A (IL-17A) production by human Th17 cells and in vitro permeation through healthy human skin achieving high total compound concentration in both skin epidermis and dermis layers.

Co-Encapsulation of Drugs for Topical Application-A Review

Achieving the best possible outcome for the therapy is the main goal of a medicine. Therefore, nanocarriers and co-delivery strategies were invented to meet this need, as they can benefit many diseases. This approach was applied specifically for cancer treatment, with some success. However, these strategies may benefit many other clinical issues. Skin is the largest and most exposed organ of the human body, with physiological and psychological properties. Due to its exposition and importance, it is not difficult to understand how many skin diseases may impact on patients' lives, representing an important burden for society. Thus, this review aims to summarize the state of the art in research concerning nanocarriers and co-delivery strategies for topical agents' applications targeting skin diseases. The challenge for the medicine of the future is to deliver the drug with spatial and temporal control. Therefore, the co-encapsulation of drugs and the appropriate form of administration for them are so important and remain as unmet needs.

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.

Topical Delivery of Atraric Acid Derived from Stereocaulon japonicum with Enhanced Skin Permeation and Hair Regrowth Activity for Androgenic Alopecia

Atraric acid (AA) is a phenolic compound isolated from Stereocaulon japonicum that has demonstrated anti-androgen properties and was used to design an alternative formulation for the treatment of alopecia. This new topical formulation was designed using a solvent mixture system composed of ethanol as a volatile vehicle, oleic acid as a permeation enhancer, and water for skin hydration. The ideal topical AA formulation (AA-TF#15) exhibited an 8.77-fold higher human skin flux and a 570% increase in dermal drug deposition, compared to 1% (w/w) AA in ethanol. In addition, compared to other formulations, AA-TF#15 (1% [w/w] AA) activated keratinocytes and human dermal papilla cell proliferation at a concentration of 50 µM AA, which is equivalent to 50 µM minoxidil. Moreover, AA-TF#15 treatment produced a significant increase in hair regrowth by 58.0% and 41.9% compared to the 1% (w/w) minoxidil and oral finasteride (1 mg/kg)-treated mice. In addition, AA-TF#15 showed a higher expression level of aldehyde dehydrogenase 1, β-catenin, cyclin D1, and pyruvate kinase M2 proteins in the skin of AA-TF#15-treated mice compared to that of those treated with minoxidil and oral finasteride. These findings suggest AA-TF#15 is an effective formulation for the treatment of scalp androgenic alopecia.

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

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

A Discursive Review of Recent Development and Patents on Glycerosomes

BACKGROUND

To achieve a target-based drug delivery with minimal side effects, novel drug delivery systems are being continuously explored. Vesicular systems are one such system that can ameliorate the bioavailability of the encapsulated drug by delivering the drug at the targeted site and can minimize the side effect.

OBJECTIVE

The objective of this patent review is to provide a vivid description of glycerosomes and their applications. Glycerosomes are sphere-shaped versatile vesicles consisting of one or more phospholipid bilayers similar to liposomes but contain a high concentration of glycerol, which modifies the liposome bilayer fluidity. Glycerosomes can encapsulate both hydrophobic and hydrophilic drugs, which makes them the promising vehicle in the field of drug delivery.

CONCLUSION

Most of the glycerosome formulations prepared were targeted for topical delivery and in particular, a cutaneous route where they have shown promising results. These vesicles are biocompatible and due to the high glycerol concentration, they have improved spreadability and penetrability. It is therefore imperative to explore the other topical routes such as ocular, vaginal, nasal, and rectal for delivery of drugs.

Nanoscale Topical Pharmacotherapy in Management of Psoriasis: Contemporary Research and Scope

Psoriasis is a typical dermal condition that has been anticipated since prehistoric times when it was mistakenly implicit in being a variant of leprosy. It is an atypical organ-specific autoimmune disorder, which is triggered by the activation of T-cells and/or B-cells. Until now, the pathophysiology of this disease is not completely explicated and still, many research investigations are ongoing. Different approaches have been investigated to treat this dreadful skin disease using various anti-psoriatic drugs of different modes of action through smart drug-delivery systems. Nevertheless, there is no ideal therapy for a complete cure of psoriasis owing to the dearth of an ideal drug-delivery system for anti-psoriatic drugs. The conventional pharmacotherapy approaches for the treatment of psoriasis demand various classes of anti-psoriatic drugs with optimum benefit/risk ratio and insignificant untoward effects. The advancement in nanoscale drug delivery had a great impact on the establishment of a nanomedicine-based therapy for better management of psoriasis in recent times. Nanodrug carriers are exploited to design and develop nanomedicine-based therapy for psoriasis. It has a promising future in the improvement of the therapeutic efficacy of conventional anti-psoriatic drugs. The present manuscript aims to discuss the pathophysiology, conventional pharmacotherapy, and contemporary research in the area of nanoscale topical drug delivery systems for better management of psoriasis including the significance of targeted pharmacotherapy in psoriasis.

Combined Orobol-Bentonite Composite Formulation for Effective Topical Skin Targeted Therapy in Mouse Model

Purpose

Orobol is an isoflavone that has a potent skin protection effect. The objective of this study was to prepare a novel bentonite-based composite formulation of orobol to enhance topical skin delivery.

Methods

The composition was optimized based on the orobol content in the composite and the in vitro release studies, followed by the in vitro and in vivo hairless mouse skin deposition studies. Physicochemical characterizations of the composite formulation were performed by powder X-ray refractometry (XRD) and scanning electron microscopy (SEM). The in vitro cytotoxicity and in vivo toxicity studies were conducted in human keratinocytes and in hairless mouse, respectively.

Results and Discussions

The in vitro release of orobol from the bentonite composites was higher than that from the suspension, which was further increased with the addition of phosphatidylcholine. The composite formulation significantly enhanced the in vitro and in vivo skin deposition of orobol in hairless mouse skin compared to the orobol suspension. Moreover, the addition of phosphatidyl choline not only improved the dissolution and incomplete release of orobol from the bentonite composite but also enhanced the deposition of orobol in the skin. XRD histograms and SEM images confirmed that the enhanced dissolution of orobol from the composite was attributed to its amorphous state on bentonite. The in vitro and in vivo toxicity studies support the safety and biocompatibility of the orobol-loaded bentonite composite formulation.

Conclusion

These findings suggest that the orobol-loaded bentonite composite formulation could be a potential topical skin delivery system for orobol.

Transdermal delivery of inflammatory factors regulated drugs for rheumatoid arthritis

Rheumatoid arthritis is a chronic autoimmune disease, with the features of recurrent chronic inflammation of synovial tissue, destruction of cartilage, and bone erosion, which further affects joints tissue, organs, and systems, and eventually leads to irreversible joint deformities and body dysfunction. Therapeutic drugs for rheumatoid arthritis mainly reduce inflammation through regulating inflammatory factors. Transdermal administration is gradually being applied to the treatment of rheumatoid arthritis, which can allow the drug to overcome the skin stratum corneum barrier, reduce gastrointestinal side effects, and avoid the first-pass effect, thus improving bioavailability and relieving inflammation. This paper reviewed the latest research progress of transdermal drug delivery in the treatment of rheumatoid arthritis, and discussed in detail the dosage forms such as gel (microemulsion gel, nanoemulsion gel, nanomicelle gel, sanaplastic nano-vesiclegel, ethosomal gel, transfersomal gel, nanoparticles gel), patch, drug microneedles, nanostructured lipid carrier, transfersomes, lyotropic liquid crystal, and drug loaded electrospinning nanofibers, which provide inspiration for the rich dosage forms of transdermal drug delivery systems for rheumatoid arthritis.

An insight on topically applied formulations for management of various skin disorders

Various types of skin disorders across each age group and in each part of geographical world are very dreadful. Despite not being fatal each time they are always of social and mental concern for suffering individuals, causing complications in millions of patients every day and require comparatively longer duration of treatment. Off late, various topical/transdermal formulations have been widely explored for the treatment of various skin ailments. The efficiency of topical therapy depends on various physiochemical properties of drugs like particle size, particle size distribution, partition coefficient, viscosity of dosage form, skin permeability, skin condition and the site of application. Therefore, in plenty of examples, long-acting topical formulations have shown to be markedly excellent in comparison to conventional dosage forms. The major advantages of topical formulations accrue from their demonstrated ability: (i) Reduced serious side effects that may occur due to undesirably higher systemic absorption of drug. (ii) Enhancement of drug accumulation at the desired site. (iii) Easy incorporation of enormous range of hydrophilic and hydrophobic drugs and (iv) Reduced risk of dose dumping and comparatively easy termination of drug release. The prospective applications of topically applied formulations and the deposition of pharmaceuticals into the skin are examined.

Topical Delivery of Hedgehog Inhibitors: Current Status and Perspectives

Systemic treatment with hedgehog inhibitors (HHis) is available to treat basal cell carcinomas but their utility is limited by adverse effects. Topical delivery methods may reduce adverse effects, but successful topical treatment depends on sufficient skin uptake, biological response, and time in tumor tissue. The aim of this review was to evaluate the current status of topical HHi delivery for BCCs and discuss barriers for translating systemic HHis into topical treatments. A literature search identified 16 preclinical studies and 7 clinical trials on the topical delivery of 12 HHis that have been clinically tested on BCCs. Preclinical studies on drug uptake demonstrated that novel formulations, and delivery- and pre-treatment techniques enhanced topical HHi delivery. Murine studies showed that the topical delivery of sonidegib, itraconazole, vitamin D₃ and CUR-61414 led to biological responses and tumor remission. In clinical trials, only topical patidegib and sonidegib led to at least a partial response in 26/86 BCCs and 30/34 patients, respectively. However, histological clearance was not observed in the samples analyzed. In conclusion, the incomplete clinical response could be due to poor HHi uptake, biodistribution or biological response over time. Novel topical delivery techniques may improve HHi delivery, but additional research on cutaneous pharmacokinetics and biological response is needed.

Topical Delivery of Elastic Liposomal Vesicles for Treatment of Middle and Inner Ear Diseases

We present a topical drug delivery mechanism through the ear canal to the middle and inner ear using liposomal nanoparticles without disrupting the integrity of the tympanic membrane. The current delivery method provides a noninvasive and safer alternative to transtympanic membrane injections, ear tubes followed by ear drops administration, and systemic drug formulations. We investigate the capability of liposomal NPs, particularly transfersomes (TLipo), used as drug delivery vesicles to penetrate the tympanic membrane (TM) and round window membrane (RWM) with high affinity, specificity, and retention time. The TLipo is applied to the ear canal and found to pass through the tympanic membrane quickly in 3 h post drug administration. They are identified in the middle ear cavity 6 h and in the inner ear 24 h after drug administration. We performed cytotoxicity in vitro and ototoxicity in vivo studies. Cell viability shows no significant difference between the applied TLipo concentration and control. Furthermore, auditory brainstem response (ABR) reveals no hearing loss in 1 week and 1 month post-administration. Immunohistochemistry results demonstrate no evidence of hair cell loss in the cochlea at 1 month following TLipo administration. Together, the data suggested that TLipo can be used as a vehicle for topical drug delivery to the middle ear and inner ear.

Macrophage targeting of nitazoxanide-loaded transethosomal gel in cutaneous leishmaniasis

Topical delivery is preferable over systemic delivery for cutaneous leishmaniasis, because of its easy administration, reduced systemic adverse effects and low cost. Nitazoxanide (NTZ) has broad-spectrum activity against various parasites and has the potential to avoid drug resistance developed by enzymatic mutations. NTZ oral formulation is associated with severe dyspepsia and stomach pain. Herein, NTZ-transethosomes (NTZ-TES) were prepared and loaded into chitosan gel (NTZ-TEG) for topical delivery. NTZ-TES were prepared by the thin-film hydration method and optimized statistically via the Box-Behnken method. The optimized formulation indicated excellent particle size (176 nm), polydispersity index (0.093), zeta potential (-26.4 mV) and entrapment efficiency (86%). The transmission electron microscopy analysis showed spherical-sized particles and Fourier-transform infrared spectroscopy analysis indicated no interaction among the excipients. Similarly, NTZ-TEG showed optimal pH, desirable viscosity and good spreadability. NTZ-TES and NTZ-TEG showed prolonged release behaviour and higher skin penetration and deposition in the epidermal/dermal layer of skin in comparison with the NTZ-dispersion. Moreover, NTZ-TES showed higher percentage inhibition, lower half-maximal inhibitory concentration (IC₅₀) against promastigotes and higher macrophage uptake. Additionally, skin irritation and histopathology studies indicated the safe and non-irritant behaviour of the NTZ-TEG. The obtained findings suggested the enhanced skin permeation and improved anti-leishmanial effect of NTZ when administered as NTZ-TEG.

Macrophage targeting of nitazoxanide-loaded transethosomal gel in cutaneous leishmaniasis

Topical delivery is preferable over systemic delivery for cutaneous leishmaniasis, because of its easy administration, reduced systemic adverse effects and low cost. Nitazoxanide (NTZ) has broad-spectrum activity against various parasites and has the potential to avoid drug resistance developed by enzymatic mutations. NTZ oral formulation is associated with severe dyspepsia and stomach pain. Herein, NTZ-transethosomes (NTZ-TES) were prepared and loaded into chitosan gel (NTZ-TEG) for topical delivery. NTZ-TES were prepared by the thin-film hydration method and optimized statistically via the Box-Behnken method. The optimized formulation indicated excellent particle size (176 nm), polydispersity index (0.093), zeta potential (-26.4 mV) and entrapment efficiency (86%). The transmission electron microscopy analysis showed spherical-sized particles and Fourier-transform infrared spectroscopy analysis indicated no interaction among the excipients. Similarly, NTZ-TEG showed optimal pH, desirable viscosity and good spreadability. NTZ-TES and NTZ-TEG showed prolonged release behaviour and higher skin penetration and deposition in the epidermal/dermal layer of skin in comparison with the NTZ-dispersion. Moreover, NTZ-TES showed higher percentage inhibition, lower half-maximal inhibitory concentration (IC₅₀) against promastigotes and higher macrophage uptake. Additionally, skin irritation and histopathology studies indicated the safe and non-irritant behaviour of the NTZ-TEG. The obtained findings suggested the enhanced skin permeation and improved anti-leishmanial effect of NTZ when administered as NTZ-TEG.

Macrophage targeting of nitazoxanide-loaded transethosomal gel in cutaneous leishmaniasis

Topical delivery is preferable over systemic delivery for cutaneous leishmaniasis, because of its easy administration, reduced systemic adverse effects and low cost. Nitazoxanide (NTZ) has broad-spectrum activity against various parasites and has the potential to avoid drug resistance developed by enzymatic mutations. NTZ oral formulation is associated with severe dyspepsia and stomach pain. Herein, NTZ-transethosomes (NTZ-TES) were prepared and loaded into chitosan gel (NTZ-TEG) for topical delivery. NTZ-TES were prepared by the thin-film hydration method and optimized statistically via the Box-Behnken method. The optimized formulation indicated excellent particle size (176 nm), polydispersity index (0.093), zeta potential (-26.4 mV) and entrapment efficiency (86%). The transmission electron microscopy analysis showed spherical-sized particles and Fourier-transform infrared spectroscopy analysis indicated no interaction among the excipients. Similarly, NTZ-TEG showed optimal pH, desirable viscosity and good spreadability. NTZ-TES and NTZ-TEG showed prolonged release behaviour and higher skin penetration and deposition in the epidermal/dermal layer of skin in comparison with the NTZ-dispersion. Moreover, NTZ-TES showed higher percentage inhibition, lower half-maximal inhibitory concentration (IC₅₀) against promastigotes and higher macrophage uptake. Additionally, skin irritation and histopathology studies indicated the safe and non-irritant behaviour of the NTZ-TEG. The obtained findings suggested the enhanced skin permeation and improved anti-leishmanial effect of NTZ when administered as NTZ-TEG.