Film-Forming Systems for Dermal Drug Delivery

Formulation and evaluation of HPMC and pullulan-based rapidly dissolving films containing cilnidipine nanosuspension

Cilnidipine is used to treat hypertension. However, it has poor solubility and undergoes extensive first-pass metabolism, which leads to poor bioavailability. This work aimed to prepare rapidly dissolving films (RDFs) containing nanosuspension of CLD with HPMC and pullulan as film-formers. These RDFs deliver the drugs through the buccal mucosa and bypass the first-pass metabolism, thereby increasing bioavailability. The nanosuspension was prepared using the nanoprecipitation technique and was optimized using the CCD. The optimized formulation had an average size and zeta potential of 362.23 nm and -39.1 mV, respectively. FT-IR studies indicated no interaction between CLD and stabilizers. DSC and XRD studies confirmed reduced crystallinity of CLD. SEM revealed the capsular morphology of nanoparticles. The optimized RDFs had a 2.83 ± 0.24 tensile strength, 11.61 ± 2.87 % elongation, 17.21 ± 1.06 s disintegration time, and in-vitro release of 91.77 ± 6.22 % in 60 min. A more than two-fold increase in drug permeation was recorded from the CLD NS-RDF as compared to the CLD CD-RDF. The CLD NS-RDF exhibited a significant increase in AUC0-24h, Cmax, and a decrease in Tmax and MRT as compared to the CLD CD-RDF. The CLD NS-RDF also had a superior effect to control the blood pressure in rats as compared to the CLD CD-RDF.

Tracking the Effect of Phosvitin (PV) Concentration on the Skin Permeation of Somatotropin (STH) from Semi-Solid Hydrogel Formulations

Recombinant human growth hormone (rhGH) is utilized in pediatric patients with short stature for a variety of indications, including those in which the primary growth defect is not related to growth hormone deficiency (GHD). However, due to the instability of the hormone in the gastrointestinal tract and its short half-life, an alternative route of administration is being sought, which may be the skin. One strategy to extend the half-life of proteins involves the use of biodegradable polymeric matrices for transdermal drug delivery systems. While hydrogels are recognized for their high stability, the transport of proteins through the skin may be hindered. To address this, the use of active carriers is being investigated to enhance the efficiency of protein permeation through the skin. In this study, an effort was made to optimize the concentration of phosphitin (PV) as a carrier for somatotropin (STH). PV is a protein that possesses a distinctive cation chelating capability and amphiphilic character. As the concentration of PV increased, the rate of its emulsifying activity increased concomitantly. Methylcellulose (MC) was used as the hydrogel matrix. The study investigated three distinct concentrations of PV to ascertain the most optimal concentration to enhance STH availability. Following the formulation of hydrogel compositions containing STH and PV, the permeation process through porcine skin was examined using Franz's chambers. The findings revealed that the incorporation of PV significantly impacted both the penetration time of STH and the extent of STH penetration. Subsequently, an extensive evaluation of the physicochemical parameters of the formulations, encompassing pH, rheological, and textural properties, was conducted to assess their suitability for skin application. This evaluation aimed to ensure not only adequate persistence time of the formulation on the skin surface but also formulation stability and persistence of the active substance (STH).

Topical formulation for wound management in animals: A paradigm shifts from conventional to advance

Chronic wounds are a significant clinical problem for the healthcare system and require several intensive efforts to improve alternative drug delivery systems for wound care. Sometimes, this is insufficient to support the healing process. There are several obstacles to effective wound therapy, such as poor healing, off-targeting, non-compliance, and frequent dosage. Animal healthcare is a much-needed service for pet owners, farmers, and government agencies. However, the varied physiology of animals presents a challenge in producing effective medicines for animal health. To improve drug therapeutic performance, reduce animal stress, and minimize adverse effects, the industry focuses on current developments in technology for wound management in animals. The literature search utilized various reviews, research articles, clinical trials, case reports, etc. Search engines like Google Scholar, PubMed, and ScienceDirect were used to retrieve data. Various keywords such as "wound dressing and animals", "antimicrobials and animal wounds", "wound healing and animals" etc. were used to search the literature. Different formulation avenues are being explored, including hydrogels, wafers, and nanoemulsions. Therefore, further research is necessary to explore wound healing techniques. Utilising various advanced drug delivery systems for veterinary medicine has significantly reduced adverse effects, the frequency of doses, and stress on animals, resulting in increased profits for the industry. However, this also requires investment in research to ensure the safety, quality, and effectiveness of drugs, and delivery systems. This article reviews the various phases involved in wound healing, multiple factors affecting wound healing, different wound healing approaches, clinical trials, and case studies.

Polysaccharide-based hydrogels for atopic dermatitis management: A review

Atopic dermatitis (AD) is the most common form of eczema and the most burdensome skin disease globally, affecting nearly 223 million. A major AD predisposition is genetic susceptibility, affecting skin barrier integrity and cell-mediated immunity. Manifesting as red, dry, and itchy skin, basic treatment involves skin hydration with emollients. Despite their effectiveness, poor patient compliance remains a major drawback. In severe cases, medicated emollients are used, but carry risks, including skin thinning, and immunosuppression. Hence, hydrogels have emerged as a promising alternative for AD management based on their ability to improve skin hydration, attributed to their hydrophilicity and high water retention capacity. Moreover, researchers have loaded hydrogels with various compounds for AD management; they also hold the potential to reduce systemic side effects of commercial drugs by enhancing dermal retention. Hydrogels address the challenges of patient compliance based on their non-greasy texture and reduced application frequency. Their appeal also stems from their versatility, as they can be fabricated from varying polymers. Due to their abundance, this review focuses on polysaccharides including alginate, cellulose, chitosan, and hyaluronic acid, which are preferred for fabricating natural and modified natural hydrogels for AD. It also briefly explores hydrogel application methods and key AD models.

Opportunities of topical drug products in a changing dermatological landscape

Despite the prevalence and the impact on quality of life of dermatological indications, drug products to treat such conditions have rarely been blockbusters. The prevailing perception of a limited commercial potential of dermatological drug products has restricted innovation and encouraged a more conservative development approach. For example, the focus was on repurposing/reformulation of existing active pharmaceutical ingredients (APIs) specifically for the topical delivery route. However, the situation is quite different today catalyzed in part by the blockbuster success of Dupixent (dupilumab), the first monoclonal antibody treatment for atopic dermatitis which has been approved by the US Food and Drug Administration (US FDA) in 2017. Dupixent's success not only encouraged the development of other biologics but also inspired the (re-)development of new dermal drug products that can reap the many benefits of topical administration. We have also witnessed a shift toward outsourcing development efforts (and associated risks) towards small- to mid-size pharmaceutical companies which often require support of contract research and development/manufacturing organizations (CRO and CDMO). Such trends also emphasize the need of greater expertise in topical formulation design, as well as associated commercial and regulatory considerations. Today, we believe that topical drug products remain not only an essential but also commercially viable class of dermatological therapeutics. In this opinion article, we will address the challenges as well as opportunities of coherent development strategies in the current market environment, formulation innovations of topical drug products and technological advances to facilitate rational topical drug formulation development.

Comprehensive developmental investigation on simvastatin enriched bioactive film forming spray using the quality by design paradigm: a prospective strategy for improved wound healing

The use of topical antimicrobials in wound healing presents challenges like risk of drug resistance and toxicity to local tissue. Simvastatin (SIM), a lipid-lowering agent which reduces the risk of cardiovascular events, is repurposed for its pleiotropic effect in wound healing. A bioactive bioadhesive polymer-based film forming spray (FFS) formulation of SIM was designed using chitosan, collagen, hyaluronic acid and optimised by employing the DoE approach. Optimised formulation demonstrated moderate viscosity (12.5 ± 0.3 cP), rapid film formation (231 ± 5.6 s), flexibility, tensile strength and sustained drug release (T80 - time for 80% drug release - 9.05 ± 0.7 h). Scanning electron microscopy (SEM) verified uniformly dispersed drug within the composite polymer matrix. SIM FFS demonstrated antimicrobial activity against gram positive and gram negative bacteria. In vivo excision wound model studies in mice affirmed the beneficent role of bioactive polymers and the efficacy of SIM FFS in wound contraction and closure, tissue remodelling and re-epithelization in comparison to standard antimicrobial preparation. Cytokines TNF- alpha, IL-6 were downregulated and IL-10 was upregulated. Biochemical markers; hydroxyproline, hexosamine and histopathology were consistent with wound contraction observed. This is an exploratory effort in repurposing SIM for wound healing in a novel dosage form, underscoring its potential as an alternative to conventional topical antimicrobials.

Design and in vitro/in vivo evaluation of chitosan-polyvinyl alcohol copolymer material cross-linked by dynamic borate ester covalent for pregabalin film-forming delivery system

This research introduced a novel polymer synthesized by combining chitosan and modified polyvinyl alcohol, cross-linked with boric acid using dynamic covalent bonds. The polymer was developed to formulate a pregabalin Film-forming system (FFS) for treating postherpetic neuralgia via topical application, showcasing notable skin adhesion and drug delivery properites. The chitosan-boric acid-modified polyvinyl alcohol polymer was analyzed using NMR, FTIR. The exceptional features of the optimized FFS were evaluated through rheometer, Differential scanning calorimetry (Tg = 45.98 °C), contact angle (θ = 78.62°). The elongation (60.05 ± 3.67 %), cohesion (56.94 ± 4.65 MPa) and skin adhesion (58.12 ± 2.99 kPa) of chitosan-boric acid-modified polyvinyl alcohol were found to be 5.2, 6.8, and 8.3 times higher than those of the pure chitosan film, attributed to the double network structure formed by the cross-linked reversible dynamic covalent bond. The optimized pregabalin FFS exhibited increased in vitro (86.25 ± 1.87 μg/g) and in vivo (100.42 ± 7.44 μg/g) skin retention amounts compared to in vivo oral administration (28.43 ± 4.61 μg/g). In summary, the utilization of borate ester dynamic covalent bonds in developing chitosan-based film-forming polymer proved beneficial in improving skin adhesion and topical therapeutic effectiveness, thereby mitigating the risk of systemic side effects associated with oral administration.

An Overview of Film-Forming Emulsions for Dermal and Transdermal Drug Delivery

Drug delivery through the skin is a widely used therapeutic method for the treatment of local dermatologic conditions. Dermal and transdermal methods of drug delivery offer numerous advantages, but some of the most important aspects of drug absorption through the skin need to be considered. Film-forming systems (FFS) represent a new mode of sustained drug delivery that can be used to replace traditional topical formulations such as creams, ointments, pastes, or patches. They are available in various forms, including solutions, gels, and emulsions, and can be categorised as film-forming gels and film-forming emulsions. Film-forming emulsions (FFE) are designed as oil-in-water (O/W) emulsions that form a film with oil droplets encapsulated in a dry polymer matrix, thus maintaining their dispersed nature. They offer several advantages, including improved solubility, bioavailability and chemical stability of lipophilic drugs. In addition, they could improve the penetration and diffusion of drugs through the skin and enhance their absorption at the target site due to the nature of the components used in the formulation. The aim of this review is to provide an up-to-date compilation of the technologies used in film-forming emulsions to support their development and availability on the market as well as the development of new pharmaceutical forms.

Fabrication and Characterization of Dissolving Microneedles Containing Oryza sativa L. Extract Complex for Enhancement of Transfollicular Delivery

Dissolving microneedles are extensively applied in drug delivery systems to enhance penetration into the skin. In this study, dissolving microneedles fabricated from polyvinylpyrrolidone K90 (PVP-K90) and hydroxypropylmethyl cellulose (HPMC) E50 in different ratios were characterized. The selected formulations incorporated Oryza sativa L. extract complex and its characteristics, transfollicular penetration, and safety were observed. The microneedles, fabricated from PVP K90: HPMC E50 in a ratio of 25:5 (P25H5) and 20:10 (P20H10), revealed excellent morphological structure, proper mechanical strength, and excellent skin insertion. P25H5 microneedles exhibited faster dissolution than P20H10 microneedles. Microneedles containing Oryza sativa L. extract complex showed excellent morphological structure via scanning electron microscopy but decreased mechanical strength. P25H5-O, which exhibited an effective ability to enter skin, was selected for further investigation. This microneedle formulation had a high percentage of drug-loading content, enhanced skin penetration via the transfollicular route, and was safe for keratinocytes. As a result, the dissolving microneedle containing Oryza sativa L. extract complex can be used to enhance transfollicular delivery through the skin with safety.

Porphyrin Photosensitizers into Polysaccharide-Based Biopolymer Hydrogels for Topical Photodynamic Therapy: Physicochemical and Pharmacotechnical Assessments

Photodynamic therapy (PDT) is an emerging treatment modality that utilizes light-sensitive compounds, known as photosensitizers, to produce reactive oxygen species (ROS) that can selectively destroy malignant or diseased tissues upon light activation. This study investigates the incorporation of two porphyrin structures, 5-(4-hydroxy-3-methoxyphenyl)-10,15,20-tris-(4-acetoxy-3-methoxyphenyl) porphyrin (P2.2.) and 5,10,15,20-tetrakis-(4-acetoxy-3-methoxyphenyl) porphyrin (P2.1.), into hydroxypropyl cellulose (HPC) hydrogels for potential use in topical photodynamic therapy (PDT). The structural and compositional properties of the resulting hydrogels were characterized using advanced techniques such as Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), atomic force microscopy (AFM), UV-Visible (UV-Vis) spectroscopy, and fluorescence spectroscopy. FTIR spectra revealed a slight shift of the main characteristic absorption bands corresponding to the porphyrins and their interactions with the HPC matrix, indicating successful incorporation and potential hydrogen bonding. XRD patterns revealed the presence of crystalline domains within the HPC matrix, indicating partial crystallization of the porphyrins dispersed within the amorphous polymer structure. TGA results indicated enhanced thermal stability of the HPC-porphyrin gels compared to 10% HPC gel, with additional weight loss stages corresponding to the thermal degradation of the porphyrins. Rheological analysis showed that the gels exhibited pseudoplastic behavior and thixotropic properties, with minimal impact on the flow properties of HPC by P2.1., but notable changes in viscosity and shear stress with P2.2. incorporation, indicating structural modifications. AFM imaging revealed a homogeneous distribution of porphyrins, and UV-Vis and fluorescence spectroscopy confirmed the retention of their photophysical properties. Pharmacotechnical evaluations showed that the hydrogels possessed suitable mechanical properties, optimal pH, high swelling ratios, and excellent spreadability, making them ideal for topical application. These findings suggest that the porphyrin-incorporated HPC hydrogels have significant potential as effective therapeutic agents for topical applications.

The effect of skin diffusion kinetics of isopropyl ester permeation enhancers on drug permeation: Role of lateral spread and penetration characteristics

The purpose of present work was to study the effects of permeation enhancers' two kinetic behaviors of simultaneous lateral diffusion and vertical penetration in the skin on its enhancing effect. The skin diffusion kinetics of isopropyl ester permeation enhancers were characterized by the innovative concentric tape peeling study and Raman imaging, which were quantitatively assessed through innovative parameters, namely, lateral-to-vertical penetration amount (CL-V) and lateral-to-vertical penetration distance (DL-V). The enhancement effect of permeation enhancers on drug flurbiprofen (FLU) was assessed by in vitro skin permeation tests, which were confirmed by transdermal water loss and skin resistance study. The relationship between kinetic parameters of permeation enhancers and permeation parameters of FLU was carried out by correlation analysis. The molecular mechanisms of effect of skin diffusion kinetics of permeation enhancers on drug permeation were characterized by molecular docking, modulated-temperature differential scanning calorimetry (MTDSC), Raman spectra, solid-state NMR and molecular dynamic simulation. The results indicated skin diffusion kinetics of short-chain (C8-C12) isopropyl ester permeation enhancers were governed by vertical penetration, while long-chain (C14-C18) ones were characterized by lateral spread. Quadratic correlation between CL-V and enhancement ratio of permeation-retention ratio of FLU (ERQ/R) (R2 = 0.95), DL-V and enhancement ratio of permeation area (ERA) of FLU (R2 = 0.98) indicating that varied skin diffusion kinetics of permeation enhancers directly influenced the barrier function of stratum corneum (SC) and further enhancing drug permeation. In terms of molecular mechanism, long-chain isopropyl ester enhancers had good miscibility with SC, leading to their high CL-V and DL-V, and causing strong interaction strength with SC and resulting in weaker skin barrier function for drug permeation. In summary, in comparison to short-chain isopropyl ester enhancers that relied on penetration, long-chain ones that depended on lateral spread exhibited greater enhancement efficacy, which guided the application of enhancers in transdermal formulations.

Integrated In Vivo and In Vitro Evaluation of a Powder-to-Hydrogel, Film-Forming Polymer Complex Base with Tissue-Protective and Microbiome-Supportive Properties

The study aimed to perform a comprehensive in vitro and in vivo evaluation of a newly developed, patent-pending, powder-to-hydrogel, film-forming polymer complex base, which possesses tissue-protective and microbiome-supportive properties, and to compare its characteristics with poloxamer 407. The study used a combination of in vitro assays, including tissue viability and cell migration, and in vivo wound healing evaluations in male diabetic mice. Microbiome dynamics at wound sites were also analyzed. The in vitro assays demonstrated that the polymer complex base was non-cytotoxic and that it enhanced cell migration over poloxamer 407. In vivo, the polymer complex base demonstrated superior wound healing capabilities, particularly in combination with misoprostol and phenytoin, as evidenced by the reduced wound area and inflammation scores. Microbiome analysis revealed favorable shifts in bacterial populations associated with the polymer complex base-treated wounds. The polymer complex base demonstrates clinical significance in wound care, potentially offering improved healing, safety and microbiome support. Its transformative properties and efficacy in drug delivery make it a promising candidate for advanced wound care applications, particularly in chronic wound management.

Development of a film-forming oleogel with increased substantivity for the treatment of psoriasis

The aim of this work was the development of a film-forming formulation (FFF) for the topical treatment of psoriasis that shows an increased substantivity compared to conventional semi-solid dosage forms. The developed formulation is an oleogel. It is based on a combination of castor oil and medium chain triglycerides, and the oil-soluble film former MP-30 (Croda GmbH, Nettetal, Germany), a polyamide that upon mixing with a polar oil entraps the oil und thus substantially increases the viscosity of the formulation up to a semisolid state. Betamethasone dipropionate (BDP) and calcipotriole (CA) were used as active pharmaceutical ingredients (APIs). Oleogels of different compositions were evaluated regarding substantivity, rheological properties, ex-vivo penetration into the skin and ex-vivo permeation through the skin. Marketed products were used as controls. It was found that the amount of betamethasone dipropionate penetrating and permeating into and through the skin from the film-forming formulation is at an intermediate value compared to the marketed products. The substantivity of the developed formulation is described by an amount of 57.7 % formulation that remains on the skin surface and is thus significantly higher compared to the marketed products. In the film forming formulation, the proportion of API penetrating the skin remains the same when the skin repetitively brought in contact with a piece of textile during the penetration experiment. In contrast with the in-market formulations tested, this proportion was reduced by up to 97 %. As a result, the developed formulations can lead to an increased patient compliance.

Formulation study of PLGA in situ films for topical delivery of salicylates

A film-forming system (FFS) represents a convenient topical dosage form for drug delivery. In this study, a non-commercial poly(lactic-co-glycolic acid) (PLGA) was chosen to formulate an FFS containing salicylic acid (SA) and methyl salicylate (MS). This unique combination is advantageous from a therapeutic point of view, as it enabled modified salicylate release. It is beneficial from a technological perspective too, because it improved thermal, rheological, and adhesive properties of the in situ film. DSC revealed complete dissolution of SA and good miscibility of MS with the polymer. MS also ensures optimal viscoelastic and adhesive properties of the film, leading to prolonged and sustained drug release. The hydrolysis of MS to active SA was very slow at skin pH 5.5, but it apparently occurred at physiological pH 7.4. The film structure is homogeneous without cracks, unlike some commercial preparations. The dissolution study of salicylates revealed different courses in their release and the influence of MS concentration in the film. The formulated PLGA-based FFS containing 5 % SA and 10 % MS is promising for sustained and prolonged local delivery of salicylates, used mainly for keratolytic and anti-inflammatory actions and pain relief.

Selective Delivery of Clindamycin Using a Combination of Bacterially Sensitive Microparticle and Separable Effervescent Microarray Patch on Bacteria Causing Diabetic Foot Infection

INTRODUCTION

Diabetic foot infection (DFI) is one of the complications of diabetes mellitus. Clindamycin (CLY) is one of the antibiotics recommended to treat DFI, but CLY given orally and intravenously still causes many side effects.

METHODS

In this study, we encapsulated CLY in a bacteria sensitive microparticle system (MP-CLY) using polycaprolactone (PCL) polymer. MP-CLY was then delivered in a separable effervescent microarray patch (MP-CLY-SEMAP), which has the ability to separate between the needle layer and separable layer due to the formation of air bubbles when interacting with interstitial fluid in the skin.

RESULT

The characterization results of MP-CLY proved that CLY was encapsulated in large amounts as the amount of PCL polymer used increased, and there was no change in the chemical structure of CLY. In vitro release test results showed increased CLY release in media cultured with Staphylococcus aureus bacteria and showed controlled release. The characterization results of MPCLY-SEMAP showed that the developed formula has optimal mechanical and penetration capabilities and can separate in 56 ± 5.099 s. An ex vivo dermatokinetic test on a bacterially infected skin model showed an improvement of CLY dermatokinetic profile from MP-CLY SEMAP and a decrease in bacterial viability by 99.99%.

CONCLUSION

This research offers proof of concept demonstrating the improved dermatokinetic profile of CLY encapsulated in a bacteria sensitive MP form and delivered via MP-CLY-SEMAP. The results of this research can be developed for future research by testing MP-CLY-SEMAP in vivo in appropriate animal models.

Carrageenan-xanthan nanocomposite film with improved bioadhesion and permeation profile in human skin: A cutaneous-friendly platform for ketoprofen local delivery

Ketoprofen (KET), commonly used for inflammation in clinical settings, leads to systemic adverse effects with prolonged use, mitigated by topical administration. Nanotechnology-based cutaneous forms, like films, may enhance KET efficacy. Therefore, this study aimed to prepare and characterize films containing KET nanoemulsions (F-NK) regarding mechanical properties, chemical composition and interactions, occlusive potential, bioadhesion, drug permeation in human skin, and safety. The films were prepared using a κ-carrageenan and xanthan gum blend (2 % w/w, ratio 3: 1) plasticized with glycerol through the solvent casting method. Non-nanoemulsioned KET films (F-K) were prepared for comparative purposes. F-NK was flexible and hydrophilic, exhibited higher drug content and better uniformity (94.40 ± 3.61 %), maintained the NK droplet size (157 ± 12 nm), and was thinner and lighter than the F-K. This film also showed increased tensile strength and Young's modulus values, enhanced bioadhesion and occlusive potential, and resulted in more of the drug in the human skin layers. Data also suggested that nano-based formulations are homogeneous and more stable than F-KET. Hemolysis and chorioallantoic membrane tests suggested the formulations' safety. Thus, the nano-based film is suitable for cutaneous KET delivery, which may improve the drug's efficacy in managing inflammatory conditions.

Film-Forming, Moisturizing, and Sensory Properties of a Cosmetic Formulation Containing Tara Gum and Brazilian Berry Extracts

The development of cosmetic formulations with moisturizing and film-forming properties has been very important to help keep skin physiology and protection. In this context, this study aimed to develop a cosmetic formulation containing Tara gum and Brazilian berry extract and evaluate its physical-mechanical, film-forming, and sensory properties. A gel formulation was developed based on Tara gum added to Plinia cauliflora extract and was characterized by its spreadability profile and sensory properties. A clinical study was carried out with ten participants to evaluate the skin microrelief, stratum corneum water content, transepidermal water loss (TEWL), and skin morphological characteristics by reflectance confocal microscopy (RCM) before and after 2 h of application of the formulations. The formulation with Brazilian berry significantly decreased the work of shear parameter, which can be correlated with improved spreadability in the sensory analysis. The clinical study showed that both formulations improved skin hydration and reduced the TEWL. The RCM imaging analysis showed the visible film on the skin surface, a decrease in the size of furrows, an increase in the reflectance of the interkeratinocytes, and reflectance of the stratum corneum for both formulations. These results were more pronounced for the formulation containing Brazilian berry. The Tara gum in the gel formulation promoted the formation and visualization of a polymeric net on the stratum corneum surface, demonstrated by the images obtained from RCM. However, the formulation added with the Brazilian berry extract improved the skin microrelief, honeycomb pattern of the epidermis, and skin hydration in deeper layers of the epidermis.

Advancements in Skin-Mediated Drug Delivery: Mechanisms, Techniques, and Applications

Skin-mediated drug delivery methods currently are receiving significant attention as a promising approach for the enhanced delivery of drugs through the skin. Skin-mediated drug delivery offers the potential to overcome the limitations of traditional drug delivery methods, including oral administration and intravenous injection. The challenges associated with drug permeation through layers of skin, which act as a major barrier, are explored, and strategies to overcome these limitations are discussed in detail. This review categorizes skin-mediated drug delivery methods based on the means of increasing drug permeation, and it provides a comprehensive overview of the mechanisms and techniques associated with these methods. In addition, recent advancements in the application of skin-mediated drug delivery are presented. The review also outlines the limitations of ongoing research and suggests future perspectives of studies regarding the skin-mediated delivery of drugs.

Advances in the transdermal delivery of antiretroviral drugs

Antiretroviral therapy regimens are successful in stopping the advancement of human immunodeficiency virus infection to acquired immunodeficiency syndrome, and other opportunistic infections. However, they do have significant disadvantages, including long-term treatment, limited oral bioavailability, inaccessibility to organs, non-adherence by patients, and the development of medication resistance. Because of the listed drawbacks of available routes and the availability of curative medicines for human immunodeficiency virus/acquired immunodeficiency syndrome, advanced solutions are required. Antiretroviral therapy transdermal delivery is one of the current strategies that have attracted much attention from many researchers. In this narrative review, various in vitro, in vivo, and ex vivo transdermal antiretroviral therapy delivery strategies were reviewed, such as transdermal patches and films, lipid-based nano-delivery systems, microneedles, chemical penetration enhancers, and iontophoresis, which showed promising results. Although the majority of studies on Antiretroviral transdermal delivery have produced hopeful findings, additional in-depth research on passive and physical enhancement techniques, both existing and new, is necessary to fully understand the potential of this route and to make it accessible to human immunodeficiency virus patients.

Plant leaf mucilage/carrageenan/Eudragit® NE30D blended films: Optimization, characterization, and pharmaceutical application

Mucilage of C. pareira leaves was utilized, being manufactured for use in pharmaceutical products. Carrageenan and Eudragit® NE30D were used to combined. Glycerin was used as a plasticizer at a concentration of 20 % w/w based on the amount of polymer used. Computer software optimized its characteristics, including tensile properties, moisture uptake, and erosion; the optimal formulation was 1.4:1.2:2.8. The percentages of optimization error ranged from 8.48 to 13.80 %. Propranolol HCl was mixed to an optimal formulation. The film layer was tight, homogeneous, and smooth, with no holes. DSC thermogram showed no interaction peaks at 101.33 °C and 170.50 °C. Propranolol HCl concentration in the film ranged from 2.18 to 2.20 mg/cm2. Propranolol HCl was quickly released from the film. The kinetic model for the release profile was first-order kinetic. Although propranolol HCl had a high-release profile, its skin permeation was limited. The permeation lag time, Jss, and Kp were 1.60-2.65 h, 0.0182-0.0338 μg/cm2/h, and 9.10-15.35 cm/h, respectively. A significant amount of propranolol HCl residue was found on the skin's surface. Glycerin appeared to influence propranolol HCl permeability. Therefore, the plant leaf mucilage/carrageenan/Eudragit® NE30D blended film can be utilized in pharmaceutical applications to control drug release from its film layer.

Preparation and Antimicrobial Activity of a Film-Forming Polyhexamethylene Biguanide Teat Disinfectant

Bovine mastitis caused by infectious pathogens can lead to a decline in production performance and an increase in elimination rate, resulting in huge losses to the dairy industry. This study aims to prepare a novel dairy cow teat disinfectant with polyhexamethylene biguanide (PHMB) as the main bactericidal component and to evaluate its bactericidal activity in vitro and its disinfection effect in dairy cow teats. PHMB disinfectant with a concentration of 3 g/L was prepared with PVA-1788, propylene glycol and glycerol as excipients. When the dilution ratio is 1:4800 and the action time is 5 min, the PHMB teat disinfectant can reduce the four types of bacteria (S. agalactiae ATCC 12386, S. dysgalactiae ATCC 35666, S. aureus ATCC 6538, and E. coli ATCC 8099) by 99.99%. PHMB teat disinfectant applied on the skin of rabbits with four bacteria types achieved an average log10 reduction greater than 4. After 30 s of PHMB teat disinfectant dipping, the bacteria of cow teats were counted prior to disinfection. The mean log10 reduction in bacteria on the skin surface of 12 cows ranged from 0.99 to 3.52 after applying the PHMB teat disinfectant for 10 min. After 12 h, the PHMB teat disinfectant achieved an average log10 reduction in bacteria from 0.27 to 0.68 (compared with that prior to disinfection). These results suggested that PHMB teat disinfection has the potential to prevent and treat mastitis-causing bacteria in dairy herds.

Polyacrylate-Cholesterol Amphiphilic Derivative: Formulation Development and Scale-up for Health Care Applications

The novel amphiphilic polyacrylate grafted with cholesterol moieties, PAAbCH, previously synthesized, was deeply characterized and investigated in the lab and on a pre-industrial scale. Solid-state NMR analysis confirmed the polymer structure, and several water-based pharmaceutical and cosmetic products were developed. In particular, stable oil/water emulsions with vegetable oils, squalene, and ceramides were prepared, as well as hydrophilic medicated films loaded with diclofenac, providing a prolonged drug release. PAAbCH also formed polyelectrolyte hydrogel complexes with chitosan, both at the macro- and nano-scale. The results demonstrate that this polymer has promising potential as an innovative excipient, acting as a solubility enhancer, viscosity enhancer, and emulsifying agent with an easy scale-up transfer process.

Hydrogel Formulations for Topical Insulin Application: Preparation, Characterization and In Vitro Permeation across the Strat-M® Membrane

Insulin has shown efficacy in the treatment of hard-to-heal wounds, which is mainly due to its role in regulating oxidative stress and inflammatory reactions. The aim of this study was to develop an insulin-hydrogel carrier based on Sepineo™ P 600 and Sepineo™ PHD 100 for application to lesional skin. Preformulation studies of the developed formulations were performed in terms of analysis of the pharmaceutical availability of insulin from the hydrogels through the Strat-M® membrane, and rheological and texture measurements. Insulin is released in a prolonged manner; after a time of 6.5 h, 4.01 IU/cm2 (53.36%) and 3.69 IU/cm2 (47.4%) of the hormone were released from the hydrogel based on Sepineo™ P 600 and Sepineo™ PHD 100, respectively. Rheological analysis showed that the hydrogels tested belong to non-Newtonian, shear-thinning systems with yield stress. The insulin-hydrogel based on Sepineo™ P 600 and Sepineo™ PHD 100 shows optimal application properties. The results obtained provide a basis for further preclinical and clinical studies.

Development of a Microfluidic Formatted Ultrasound-Controlled Monodisperse Lipid Vesicles' Hydrogel Dressing Combined with Ultrasound for Transdermal Drug Delivery System

Transdermal drug delivery system (TDDS) has attracted much attention in the pharmaceutical technology area. However, the current methods are difficult to ensure penetration efficiency, controllability, and safety in the dermis, so its widespread clinical use has been limited. This work proposes an ultrasound-controlled monodisperse lipid vesicles (U-CMLVs) hydrogel dressing, which combines with ultrasound to form TDDS. Using microfluidic technology, prepare size controllable U-CMLVs with high drug encapsulation efficiency and quantitative encapsulation of ultrasonic response materials, and even uniform mix them with hydrogel to prepare the required thickness of dressings. The high encapsulation efficiency can ensure sufficient dosage of the drugs and further realize the control of ultrasonic response through quantitative encapsulation of ultrasound-responsive materials. Using high frequency (5 MHz, 0.4 W cm-2 ) and low frequency (60 kHz, 1 W cm-2 ) ultrasound to control the movement and rupture of U-CMLVs, the contents not only penetrate the stratum corneum into the epidermis but also break through the bottleneck of penetration efficiency, and deep into the dermis. These findings provide the groundwork for deep, controllable, efficient, and safe drug delivery through TDDS and lay a foundation for further expanding its application.

Design and Study of Nanoceria Modified by 5-Fluorouracil for Gel and Polymer Dermal Film Preparation

In this work we studied nanoceria (CeO2NPs) and nanoceria modified by 5-fluorouracil (5FU) as potential APIs. Nanoceria were synthesized by precipitation in a matrix of hydroxyethyl cellulose or hydroxypropylmethyl cellulose, using cerium (III) nitrate and meglumine. Nanoceria properties were estimated by UV, FTIR and X-ray photoelectron spectra; scanning electron and atomic force microscopy; powder X-ray diffraction patterns and energy dispersive X-ray microanalysis. The cytotoxicity of nanoceria and polymer-protected nanoparticles was evaluated using the established cell line NCTC clone 929 (C3H/An mouse, subcutaneous connective tissue, clone of L. line). The morphology and metabolic activity of nanoparticles at 10 μg∙mL-1 of cells was not significant. In addition, the cytotoxic effects of nanoceria were assessed on two human colorectal cancer cell lines (HT29 and HCT116), murine melanoma B16 cells and normal human skin fibroblasts. An inhibitory effect was shown for HCT116 human colorectal cancer cells. The IC50 values for pure CeO2NPs and CeO2NPs-5FU were 219.0 ± 45.6 μg∙mL-1 and 89.2 ± 14.0 μg∙mL-1, respectively. On the other hand, the IC50 of 5FU in the combination of CeO2NPs-5FU was 2-fold higher than that of pure 5FU, amounting to 5.0 nmol∙mL-1. New compositions of nanoceria modified by 5-fluorouracil in a polymer matrix were designed as a dermal polymer film and gel. The permeability of the components was studied using a Franz cell.

Design and Study of Nanoceria Modified by 5-Fluorouracil for Gel and Polymer Dermal Film Preparation

In this work we studied nanoceria (CeO2NPs) and nanoceria modified by 5-fluorouracil (5FU) as potential APIs. Nanoceria were synthesized by precipitation in a matrix of hydroxyethyl cellulose or hydroxypropylmethyl cellulose, using cerium (III) nitrate and meglumine. Nanoceria properties were estimated by UV, FTIR and X-ray photoelectron spectra; scanning electron and atomic force microscopy; powder X-ray diffraction patterns and energy dispersive X-ray microanalysis. The cytotoxicity of nanoceria and polymer-protected nanoparticles was evaluated using the established cell line NCTC clone 929 (C3H/An mouse, subcutaneous connective tissue, clone of L. line). The morphology and metabolic activity of nanoparticles at 10 μg∙mL−1 of cells was not significant. In addition, the cytotoxic effects of nanoceria were assessed on two human colorectal cancer cell lines (HT29 and HCT116), murine melanoma B16 cells and normal human skin fibroblasts. An inhibitory effect was shown for HCT116 human colorectal cancer cells. The IC50 values for pure CeO2NPs and CeO2NPs-5FU were 219.0 ± 45.6 μg∙mL−1 and 89.2 ± 14.0 μg∙mL−1, respectively. On the other hand, the IC50 of 5FU in the combination of CeO2NPs-5FU was 2-fold higher than that of pure 5FU, amounting to 5.0 nmol∙mL−1. New compositions of nanoceria modified by 5-fluorouracil in a polymer matrix were designed as a dermal polymer film and gel. The permeability of the components was studied using a Franz cell.

Myricetin Nanofibers Enhanced Water Solubility and Skin Penetration for Increasing Antioxidant and Photoprotective Activities

Excessive exposure to ultraviolet radiation (UV) can induce oxidative stress through the over-production of reactive oxygen species (ROS) on the skin. Myricetin (MYR), a natural flavonoid compound, significantly inhibited UV-induced keratinocyte damage; however, its bioavailability is limited by its poor water solubility and inefficient skin penetration ability, which subsequently influences its biological activity. The purpose of the study was to develop a myricetin nanofibers (MyNF) system of hydroxypropyl-β-cyclodextrin (HPBCD)/polyvinylpyrrolidone K120 (PVP)-loaded with MYR that would enhance the water solubility and skin penetration by changing the physicochemical characteristics of MYR, including reducing the particle size, increasing the specific surface area, and amorphous transformation. The results also revealed that the MyNF can reduce cytotoxicity in HaCaT keratinocytes when compared with MYR; additionally, MyNF had better antioxidant and photoprotective activity than raw MYR for the UVB-induced HaCaT keratinocytes damage model due to the MyNF increased water solubility and permeability. In conclusion, our results demonstrate that MyNF is a safe, photostable, and thermostable topical ingredient of antioxidant nanofibers to enhance the skin penetration of MYR and prevent UVB-induced skin damage.

An Imidazolium-Based Ionic Liquid as a Model to Study Plasticization Effects on Cationic Polymethacrylate Films

Ionic liquids (ILs) have been touted as effective and environmentally friendly agents, which has driven their application in the biomedical field. The study compares the effectiveness of an IL agent, 1-hexyl-3-methyl imidazolium chloride ([HMIM]Cl), to current industry standards for plasticizing a methacrylate polymer. Industrial standards glycerol, dioctyl phthalate (DOP) and the combination of [HMIM]Cl with a standard plasticizer was also evaluated. Plasticized samples were evaluated for stress-strain, long-term degradation, thermophysical characterizations, and molecular vibrational changes within the structure, and molecular mechanics simulations were performed. Physico-mechanical studies showed that [HMIM]Cl was a comparatively good plasticizer than current standards reaching effectiveness at 20-30% w/w, whereas plasticizing of standards such as glycerol was still inferior to [HMIM]Cl even at concentrations up to 50% w/w. Degradation studies show HMIM-polymer combinations remained plasticized for longer than other test samples, >14 days, compared to glycerol <5 days, while remaining more pliable. The combination of [HMIM]Cl-DOP was effective at concentrations >30% w/w, demonstrating remarkable plasticizing capability and long-term stability. ILs used as singular agents or in tandem with other standards provided equivalent or better plasticizing activity than the comparative free standards.

Nitrocellulose Based Film-Forming Gels with Cinnamon Essential Oil for Covering Surface Wounds

Acute and chronic wounds caused by assorted reasons impact patient's quality of life. Films are one of the main types of moisture retentive dressings for wounds. To improve the healing of the wound, films must ensure there is no microorganism contamination, protect from negative environmental effects, and support optimal moisture content. The aim of this study was to formulate optimal film-forming gel compositions that would have good physico-chemical properties and be suitable for wound treatment. Nitrocellulose, castor oil, ethanol (96%), ethyl acetate, and cinnamon leaf essential oil were used to create formulations. During the study, the drying rate, adhesion, flexibility, tensile strength, cohesiveness, swelling, water vapor penetration, pH value, and morphology properties of films were examined. Results showed that optimal concentrations of nitrocellulose for film-forming gel production were 13.4% and 15%. The concentrations of nitrocellulose and cinnamon leaf essential oil impacted the films' physicochemical properties (drying rate, swelling, adhesion, flexibility, etc.). The swelling test showed that films of formulations could absorb significant amounts of simulant wound exudate. Film-forming gels and films showed no microbial contamination and were stable three months after production.

Science of, and insights into, thermodynamic principles for dermal formulations

Studies have demonstrated the significant role of the thermodynamic activity of drugs in skin drug delivery. This thermodynamic activity works as a driving force for increasing/improving the absorption of drugs by the skin. It can be changed according to the physicochemical parameters (e.g., solubility, partition coefficient, and water activity) of the drug in the vehicle. Thermodynamic principles have been used for the development of novel topical and transdermal delivery systems, demonstrating the importance of thermodynamic activity in enhancing drug permeation through the skin. In this review, we provide insights into thermodynamic principles and their roles in optimizing topical and transdermal drug delivery systems.

Film Forming Systems for Delivery of Active Molecules into and across the Skin

We have investigated delivery systems that can form a structured matrix film on the skin after their application. In a previous work, we have shown that Weblike film forming systems (also called Pouches Drug Delivery Systems, PDDS) enable enhanced skin delivery of the incorporated molecules. These delivery systems are composed of one or more phospholipids, a short-chain alcohol, a polymer and optionally water. In this work, we continue the investigation and characterization of Weblike carriers focusing on some factors affecting the delivery properties such as components concentration and mode of application on the skin. Upon non-occluded application on the skin, the systems dry rapidly, forming a web-like structured film. Lidocaine, Ibuprofen, FITC and Cannabidiol are molecules with various physico-chemical properties that were incorporated in the carrier. The systems were tested in a number of in vitro and in vivo experiments. Results of the in vitro permeation of Ibuprofen through porcine skin indicated two-fold delivery through the skin of Ibuprofen when applied from our Weblike system in comparison with a nanovesicular carrier, the ethosome. We also have investigated weblike systems containing hemp seed oil (HSO). This addition enhanced the film's ability to deliver lipophilic molecules to the deeper skin layers, leading to an improved pharmacodynamic effect. In analgesic tests carried out in a pain mice model following one hour application of CBD in Weblike system with and without HSO, the number of writhing episodes was decreased from 29 in the untreated animals to 9.5 and 18.5 writhes, respectively. The results of our work open the way towards a further investigation of Weblike film forming systems containing drugs for improved dermal and transdermal treatment of various ailments.

Spray Film-Forming systems as promising topical in situ Systems: A review

Spray film-forming systems (SFFSs) provide great potential for the treatment of various types of wounds. Such systems afford to prolong the action of active substances, to prevent cross-contamination, and to ensure accelerated wound healing. Spray films are known since the mid-20th century, and nowadays they are widely used to treat minor skin injuries, but numerous clinical cases describe their successful use in the treatment of burns, wounds, bedsores, etc. The current level of polymer development and composite synthesis has greatly expanded the possibilities of creating compositions of spray film-forming systems. Scattered information and lack of standardization of such delivery systems creates difficulties for pharmaceutical development. This review highlights most of the existing requirements and suggestions from studies to standardize the characteristics of SFFSs and classify them based on scientific sources and regulatory documentation, as well as the position of such systems in the pharmaceutical market. The search and evaluation of known characterization methods and their modifications, as well as the approval of their list (separately for development and for standardization) can potentially increase the research interest in the problem of spray film-forming systems development and contribute to the registration of new drugs and medical devices in this promising dosage form, including with its own pharmacological effect.

Preparation and Evaluation of Vitamin D3 Supplementation as Transdermal Film-Forming Solution

Vitamin D3 is available in oral and injectable dosage forms. Interest in the transdermal route as an alternative to the oral and parenteral routes has grown recently. In this study, several film-forming solutions for the transdermal delivery of vitamin D3 were prepared. They contained 6000 IU/mL of vitamin D3 that formed a dry and acceptable film in less than 5 min after application. The formulations consisted of ethanol and acetone 80:20, and one or more of the following ingredients: Eudragit L100-55, PVP, PG, limonene, oleic acid, camphor, and menthol. Vitamin D3 release was studied from both the film-forming solution and pre-dried films using a Franz diffusion cell. The film-forming solution released a significant amount of vitamin D3 compared to the dry film, which is attributed mostly to the saturation driving force due to the evaporation of volatile solvents. In vitro permeation studies through artificial skin Strat M® membrane revealed that the cumulative amount of vitamin D3 permeated after 24 h under the experimental conditions was around 800 IU across 3.14 cm2. The cumulative permeation curve showed faster permeation in earlier stages. Young's modulus, viscosity, and pH of the formulations were determined. Most of the formulations were stable for 3 weeks.

The use of natural gums to produce nano-based hydrogels and films for topical application

Natural gums are a source of biopolymeric materials with a wide range of applications for multiple purposes. These polysaccharides are extensively explored due to their low toxicity, gelling and thickening properties, and bioadhesive potential, which have sparked interest in researchers given their use in producing pharmaceutic dosage forms compared to synthetic agents. Hence, gums can be used as gelling and film-forming agents, which are suitable platforms for topical drug administration. Additionally, recent studies have demonstrated the possibility of obtaining nanocomposite materials formed by a polymeric matrix of gums associated with nanoscale carriers that have shown superior drug delivery performance and compatibility with multiple administration routes compared to starting components. In this sense, research on topical natural gum-based form preparation containing drug-loaded nanocarriers was detailed and discussed herein. A special focus was devoted to the advantages achieved regarding physicochemical and mechanical features, drug delivery capacity, permeability through topical barriers, and biocompatibility of the hydrogels and polymeric films.

Proanthocyanidins from Vaccinium vitis-idaea L. Leaves: Perspectives in Wound Healing and Designing for Topical Delivery

The compositions and health-beneficial properties of lingonberry leaves (Vaccinium vitis-idaea L.) are well established; however, their proanthocyanidins are still heavily underutilized. Optimizing their delivery systems is key to enabling their wider applications. The present study investigates the phytochemical and 'wound-healing' properties of proanthocyanidin-rich fraction(s) (PRF) from lingonberry leaves as well as the development of optimal dermal film as a proanthocyanidin delivery system. The obtained PRF was subjected to HPLC-PDA and DMAC analyses to confirm the qualitative and quantitative profiles of different polymerization-degree proanthocyanidins. A 'wound healing' in vitro assay was performed to assess the ability of PRF to modulate the wound environment for better healing. Low concentrations of lingonberry proanthocyanidins were found to accelerate 'wound' closures, while high levels inhibited human fibroblast migration. Fifteen dermal films containing PRF were prepared and evaluated based on their polymer (MC, HEC, PEG 400) compositions, and physical, mechanical, and biopharmaceutical properties using an experimental design. The composition containing 0.30 g of MC, 0.05 g of HEC, and 3.0 g of PEG 400 was selected as a promising formulation for PRF delivery and a potentially effective functional wound dressing material, supporting the need for further investigations.

The Potential of Pharmaceutical Hydrogels in the Formulation of Topical Administration Hormone Drugs

Hormones have attracted considerable interest in recent years due to their potential use in treatment of many diseases. Their ability to have a multidirectional effect leads to searching for new and increasingly effective drugs and therapies. Limitations in formulating drug forms containing hormones are mainly due to their low enzymatic stability, short half-life and limited bioavailability. One of the solutions may be to develop a hydrogel as a potential hormone carrier, for epidermal and transdermal application. This review discusses the main research directions in developing this drug formulation. The factors determining the action of hormones as drugs are presented. An analysis of hydrogel substrates and permeation enhancers that have the potential to enhance the efficacy of hormones applied to the skin is reviewed.

Solid Dispersions Incorporated into PVP Films for the Controlled Release of Trans-Resveratrol: Development, Physicochemical and In Vitro Characterizations and In Vivo Cutaneous Anti-Inflammatory Evaluation

Trans-resveratrol can promote various dermatological effects. However, its high crystallinity decreases its solubility and bioavailability. Therefore, solid dispersions have been developed to promote its amorphization; even so, they present as powders, making cutaneous controlled drug delivery unfeasible and an alternative necessary for their incorporation into other systems. Thus, polyvinylpyrrolidone (PVP) films were chosen with the aim of developing a controlled delivery system to treat inflammation and bacterial infections associated with atopic dermatitis. Four formulations were developed: two with solid dispersions (and trans-resveratrol) and two as controls. The films presented with uniformity, as well as bioadhesive and good barrier properties. X-ray diffraction showed that trans-resveratrol did not recrystallize. Fourier-transform infrared spectroscopy (FT-IR) and thermal analysis evidenced good chemical compatibilities. The in vitro release assay showed release values from 82.27 ± 2.60 to 92.81 ± 2.50% (being a prolonged release). In the in vitro retention assay, trans-resveratrol was retained in the skin, over 24 h, from 42.88 to 53.28%. They also had low cytotoxicity over fibroblasts. The in vivo assay showed a reduction in inflammation up to 66%. The films also avoided Staphylococcus aureus’s growth, which worsens atopic dermatitis. According to the results, the developed system is suitable for drug delivery and capable of simultaneously treating inflammation and infections related to atopic dermatitis.

Coupling AFM, DSC and FT-IR towards Elucidation of Film-Forming Systems Transformation to Dermal Films: A Betamethasone Dipropionate Case Study

Polymeric film-forming systems have emerged as an esthetically acceptable option for targeted, less frequent and controlled dermal drug delivery. However, their dynamic nature (rapid evaporation of solvents leading to the formation of thin films) presents a true characterization challenge. In this study, we tested a tiered characterization approach, leading to more efficient definition of the quality target product profiles of film-forming systems. After assessing a number of physico-chemico-mechanical properties, thermal, spectroscopic and microscopic techniques were introduced. Final confirmation of betamethasone dipropionate-loaded FFS biopharmaceutical properties was sought via an in vitro skin permeation study. A number of applied characterization methods showed complementarity. The sample based on a combination of hydrophobic Eudragit^® RS PO and hydroxypropyl cellulose showed higher viscosity (47.17 ± 3.06 mPa·s) and film thickness, resulting in sustained skin permeation (permeation rate of 0.348 ± 0.157 ng/cm² h), and even the pH of the sample with Eudragit^® NE 30D, along with higher surface roughness and thermal analysis, implied its immediate delivery through the epidermal membrane. Therefore, this study revealed the utility of several methods able to refine the number of needed tests within the final product profile.

Confocal Raman Spectroscopic Imaging for Evaluation of Distribution of Nano-Formulated Hydrophobic Active Cosmetic Ingredients in Hydrophilic Films

Film-forming systems are highly relevant to the topical administration of active ingredients (AI) to the body. Enhanced contact with the skin can increase the efficacy of delivery and penetration during prolonged exposure. However, after the evaporation of volatile solvents to form a thin film, the distribution of the ingredient should remain homogenous in order to ensure the effectiveness of the formula. This is especially critical for the use of hydrophobic molecules that have poor solubility in hydrophilic films. In order to address this concern, hydroxyphenethyl esters (PHE) of Punica granatum seed oil were prepared as a nanosuspension stabilised by poloxamers (NanoPHE). NanoPHE was then added to a formulation containing polyvinyl alcohol (PVA) as a film forming agent, Glycerol as a plasticiser and an antimicrobial agent, SepicideTM HB. Despite their reliability, reference methods such as high-performance liquid chromatography are increasingly challenged due to the need for consumables and solvents, which is contrary to current concerns about green industry in the cosmetics field. Moreover, such methods fail to provide spatially resolved chemical information. In order to investigate the distribution of ingredients in the dried film, Confocal Raman imaging (CRI) coupled to Non-negatively Constrained Least Squares (NCLS) analysis was used. The reconstructed heat maps from a range of films containing systematically varying PHE concentrations highlighted the changes in spectral contribution from each of the ingredients. First, using NCLS scores it was demonstrated that the distributions of PVA, Glycerol, SepicideTM HB and PHE were homogenous, with respective relative standard deviations (RSD) of 3.33%, 2.48%, 2.72% and 6.27%. Second, the respective relationships between ingredient concentrations in the films and their Raman responses, and the spectral abundance were established. Finally, a model for absolute quantification for PHE was be constructed using the percentage of spectral abundance. The prepared %w/w concentrations regressed against predicted %w/w concentrations, displaying high correlation (R2 = 0.995), while the Root Mean Squared Error (0.0869% w/w PHE) confirmed the precision of the analysis. The mean percent relative error of 3.75% indicates the accuracy to which the concentration in dried films could be determined, further supporting the suitability of CRI for analysis of composite solid film matrix. Ultimately, it was demonstrated that nanoformulation of hydrophobic PHE provides homogenous distribution in PVA based film-forming systems independent of the concentration of NanoPHE used in the formula.

Novel Temperature Responsive Films Impregnated with Silver Nano Particles (Ag-NPs) as Potential Dressings for Wounds

Silver nanoparticles have attracted wide interest in medicine on account of their antibacterial activity. We report in this paper, the antibacterial activity and biocompatibility of a temperature responsive topical film fabricated from pullulan-g-pNIPAM and impregnated with two different concentrations (15 ppm and 30 ppm) of silver nanoparticles (Ag-NPs). The release of silver from the film under the influence of temperature above the LCST has been studied and the in vitro release profile of the films has been compared with a marketed silver nano formulation, 'Meganano gel'. The release of silver from the films has a distinctive profile characterized by a sustained release over a period of 48 hrs, which is comparable to the marketed formulation. The films exhibit excellent swelling properties, making them ideal materials for absorption of exudates from wounds. The antibacterial activity of the films has been established at physiological temperature against gram-positive S. aureus and gram-negative E. coli and compared with the marketed formulation. A cytotoxicity evaluation on HeK293 cells has demonstrated their biocompatibility. The nanocomposite films are thus a new therapeutic device for management of non-healing wounds being constructed from temperature responsive polymers that release Ag-NPs when the temperature of the wound exudate is slightly higher than normal.

Ethyl Cellulose and Hydroxypropyl Methyl Cellulose Blended Methotrexate-Loaded Transdermal Patches: In Vitro and Ex Vivo

Transdermal drug delivery systems (TDDSs) have become innovative, fascinating drug delivery methods intended for skin application to achieve systemic effects. TDDSs overcome the drawbacks associated with oral and parenteral routes of drug administration. The current investigation aimed to design, evaluate and optimize methotrexate (MTX)-loaded transdermal-type patches having ethyl cellulose (EC) and hydroxypropyl methyl cellulose (HPMC) at different concentrations for the local management of psoriasis. In vitro release and ex vivo permeation studies were carried out for the formulated patches. Various formulations (F1–F9) were developed using different concentrations of HPMC and EC. The F1 formulation having a 1:1 polymer concentration ratio served as the control formulation. ATR–FTIR analysis was performed to study drug–polymer interactions, and it was found that the drug and polymers were compatible with each other. The formulated patches were further investigated for their physicochemical parameters, in vitro release and ex vivo diffusion characteristics. Different parameters, such as surface pH, physical appearance, thickness, weight uniformity, percent moisture absorption, percent moisture loss, folding endurance, skin irritation, stability and drug content uniformity, were studied. From the hydrophilic mixture, it was observed that viscosity has a direct influence on drug release. Among all formulated patches, the F5 formulation exhibited 82.71% drug release in a sustained-release fashion and followed an anomalous non-Fickian diffusion. The permeation data of the F5 formulation exhibited about a 36.55% cumulative amount of percent drug permeated. The skin showed high retention for the F5 formulation (15.1%). The stability study indicated that all prepared formulations had very good stability for a period of 180 days. Therefore, it was concluded from the present study that methotrexate-loaded transdermal patches with EC and HPMC as polymers at different concentrations suit TDDSs ideally and improve patient compliance for the local management of psoriasis.

Topical Artocarpus communis Nanoparticles Improved the Water Solubility and Skin Permeation of Raw A. communis Extract, Improving Its Photoprotective Effect

Antioxidants from plant extracts are often used as additives in skincare products to prevent skin problems induced by environmental pollutants. Artocarpus communis methanol extract (ACM) has many biological effects, such as antioxidant, anti-inflammatory, wound healing, and photoprotective effects; however, the poor water solubility of raw ACM has limited its applications in medicine and cosmetics. Topical antioxidant nanoparticles are one of the drug-delivery systems for overcoming the poor water solubility of antioxidants for increasing their skin penetration. The present study demonstrated that ACM-loaded hydroxypropyl-β-cyclodextrin and polyvinylpyrrolidone K30 nanoparticles (AHP) were successfully prepared and could effectively increase the skin penetration of ACM through changing the physicochemical characteristics of raw ACM, including reducing the particle size, increasing the surface area, and inducing amorphous transformation. Our results also revealed that AHP had significantly better antioxidant activity than raw ACM for preventing photocytotoxicity because the AHP formulation increased the cellular uptake of the ACM in UVB-irradiated HaCaT keratinocytes. In conclusion, our results suggest that AHP may be used as a good topical antioxidant nanoparticle for delivering ACM into deep layers of the skin for preventing UVB-induced skin problems.