Formulation and evaluation of clotrimazole transdermal spray

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.

Chitosan and α-cellulose-based mupirocin topical film-forming spray: Optimization, in vitro characterization, antimicrobial studies and wound healing activity

The study aimed to develop a biopolymer-based mupirocin film-forming spray (MUP-FFS) for wound healing using chitosan and α-cellulose. MUP-FFS formulation was optimized by box-Behnken design, wherein the amount of chitosan, glycerol, and microfluidizer cycles showed a significant effect on the drying time and sprayability, but drug release remained unaffected. The optimized MUP-FFS formulation prepared by 13 microfluidizer cycles containing chitosan (0.125 %), glycerol (2.76 %) was quickly sprayable with 235 s drying time. The viscosity, spray uniformity and occlusive potential were found optimum for MUP-FFS. MUP-FFS released 98.066 % of MUP, 2-fold and 4-fold greater than the marketed ointment and MUP-API. The transmission electron microscopy displayed a homogeneous fibrous network, and scanning electron microphotographs showed uniform drug distribution on the MUP-film surface. The antimicrobial study revealed the efficacy of MUP-FFS against S.aureus and E.coli, wherein the former was more susceptible to formulation than the later. MUP-FFS indicated better wound contraction and healing than other groups on 7th and 14th day in rats. On Day-21, MUP-FFS could regress TGF-β1 to a normal level similar to the marketed formulation, which was also reflected in histopathological observations. Therefore, MUP-FFS can be a treatment option for chronic wounds, applied without touch and with minimal mechanical pressure.

Clotrimazole-Loaded Borneol-Based In Situ Forming Gel as Oral Sprays for Oropharyngeal Candidiasis Therapy

Oral candidiasis encompasses fungal infections of the tongue and other oral mucosal sites with fungal overgrowth and its invasion of superficial oral tissues. Borneol was assessed in this research as the matrix-forming agent of clotrimazole-loaded in situ forming gel (ISG) comprising clove oil as the co-active agent and N-methyl pyrrolidone (NMP) as a solvent. Their physicochemical properties, including pH, density, viscosity, surface tension, contact angle, water tolerance, gel formation, and drug release/permeation, were determined. Their antimicrobial activities were tested using agar cup diffusion. The pH values of clotrimazole-loaded borneol-based ISGs were in the range of 5.59-6.61, which are close to the pH of 6.8 of saliva. Increasing the borneol content in the formulation slightly decreased the density, surface tension, water tolerance, and spray angle but increased the viscosity and gel formation. The borneol matrix formation from NMP removal promoted a significantly (p < 0.05) higher contact angle of the borneol-loaded ISGs on agarose gel and porcine buccal mucosa than those of all borneol-free solutions. Clotrimazole-loaded ISG containing 40% borneol demonstrated appropriate physicochemical properties and rapid gel formation at microscopic and macroscopic levels. In addition, it prolonged drug release with a maximum flux of 370 µg·cm^-2 at 2 days. The borneol matrix generated from this ISG obsentively controlled the drug penetration through the porcine buccal membrane. Most clotrimazole amounts still remained in formulation at the donor part and then the buccal membrane and receiving medium, repectively. Therefore, the borneol matrix extended the drug release and penetration through the buccal membrane efficiently. Some accumulated clotrimazole in tissue should exhibit its potential antifugal activity against microbes invading the host tissue. The other predominant drug release into the saliva of the oral cavity should influence the pathogen of oropharyngeal candidiasis. Clotrimazole-loaded ISG demonstrated efficacious inhibition of growth against S. aureus, E. coli, C. albicans, C. krusei, C. Lusitaniae, and C. tropicalis. Consequently, the clotrimazole-loaded ISG exhibited great potential as a drug delivery system for oropharyngeal candidiasis treatment by localized spraying.

Therapeutic Deep Eutectic Solvents: A Comprehensive Review of Their Thermodynamics, Microstructure and Drug Delivery Applications

Deep eutectic solvents (DES) are multicomponent liquids that are usually formed by coupling a hydrogen bond donor and acceptor leading to strong non-covalent (NC) intermolecular networking and profound depression in the melting point of the system. Pharmaceutically, this phenomenon has been exploited to improve drugs' physicochemical properties, with an established DES therapeutic subcategory, therapeutic deep eutectic solvents (THEDES). THEDES preparation is usually via straightforward synthetic processes with little involvement of sophisticated techniques, which, in addition to its thermodynamic stability, make these multi-component molecular adducts a very attractive alternative for drug enabling purposes. Other NC bonded binary systems (e.g., co-crystals and ionic liquids) are utilized in the pharmaceutical field for enhancing drug's behaviours. However, a clear distinction between these systems and THEDES is scarcely discussed in the current literature. Accordingly, this review provides a structure-based categorization for DES formers, a discussion of its thermodynamic properties and phase behaviour, and it clarifies the physicochemical and microstructure boundaries between DES and other NC systems. Additionally, a summary of its preparation techniques and their experimental conditions preparation is supplied. Instrumental analysis techniques can be used to characterize and differentiate DES from other NC mixtures, hence this review draws a road map to for this purpose. Since this work mainly focuses on pharmaceutical applications of DES, all types of THEDES including the highly discussed types (conventional, drugs dissolved in DES and polymer based) in addition to the less discussed categories are covered. Finally, the regulatory status of THEDES was investigated despite the current unclear situation.

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.

Sequential Injection Analysis for Automation and Evaluation of Drug Liberation Profiles: Clotrimazole Liberation Monitoring

A fully automated sequential injection system was tested in terms of its application in liberation testing, and capabilities and limitations were discussed for clotrimazole liberation from three semisolid formulations. An evaluation based on kinetic profiles obtained in short and longer sampling intervals and steady-state flux values were applied as traditional methods. The obtained clotrimazole liberation profile was faster in the case of Delcore and slower for Clotrimazol AL and Canesten cream commercial formulations. The steady-state flux values for the tested formulations were 52 µg cm^-2 h^-1 for Canesten, 35 µg cm^-2 h^-1 for Clotrimazol AL, and 7.2 µg cm^-2 h^-1 for Delcore measured in 4 min sampling intervals. A simplified approach for the evaluation of the initial rate based on the gradient between the second and third sampling points was used for the first time and was found to correspond well with the results of the conventional methods. A comparison based on the ratio of the steady-state flux and the initial rate values for Canesten and Clotrimazol AL proved the similarity of the obtained results. The proposed alternative was successfully implemented for the comparison of short-term kinetic profiles. Consequently, a faster and simpler approach for dissolution/liberation testing can be used.

Film-Forming Spray of Water-Soluble Chitosan Containing Liposome-Coated Human Epidermal Growth Factor for Wound Healing

Human epidermal growth factor (hEGF) has been known to have excellent wound-healing activity. However, direct application to the wound area can lead to low hEGF bioavailability due to protease enzymes or endocytosis. The use of liposomes as coatings and carriers can protect hEGF from degradation by enzymes, chemical reactions, and immune reactions. Sustained release using a matrix polymer can also keep the levels of hEGF in line with the treatment. Therefore, this study aimed to develop a film-forming spray of water-soluble chitosan (FFSWSC) containing hEGF-liposomes as a potential wound dressing. The hEGF-liposomes were prepared using the hydration film method, and the preparation of the FFSWSC was achieved by the ionic gelation method. The hydration film method produced hEGF-liposomes that were round and spread with a Z-average of 219.3 nm and encapsulation efficiency of 99.87%, whereas the film-forming solution, which provided good sprayability, had a formula containing 2% WSC and 3% propylene glycol with a viscosity, spray angle, droplet size, spray weight, and occlusion factor of 21.94 ± 0.05 mPa.s, 73.03 ± 1.28°, 54.25 ± 13.33 µm, 0.14 ± 0.00 g, and 14.57 ± 3.41%, respectively. The pH, viscosity, and particle size of the FFSWSC containing hEGF-liposomes were stable during storage for a month in a climatic chamber (40 ± 2 °C, RH 75 ± 5%). A wound healing activity test on mice revealed that hEGF-liposomes in FFSWSC accelerated wound closure significantly, with a complete wound closure on day 6. Based on the findings, we concluded that FFSWSC containing hEGF-liposomes has the potential to be used as a wound dressing.

Film-Forming Sprays for Topical Drug Delivery

Film-forming sprays offer many advantages compared to conventional topical preparations because they can provide uniform drug distribution and dose, increased bioavailability, lower incidence of irritation, continuous drug release, and accelerated wound healing through moisture control. Film-forming sprays consist of polymers and excipients that improve the characteristics of preparations and enhance the stability of active substances. Each type of polymer and excipient will produce films with different features. Therefore, the various types of polymers and excipients and their evaluation standards need to be examined for the development of a more optimal form of film-forming spray. The selected literature included research on polymers as film-forming matrices and the application of these sprays for medical purposes or for potential medical use. This article discusses the types and concentrations of polymers and excipients, sprayer types, evaluations, and critical parameters in determining the sprayability and film characteristics. The review concludes that both natural and synthetic polymers that have in situ film or viscoelastic properties can be used to optimise topical drug delivery.

Rational selection of antifungal drugs to propose a new formulation strategy to control Candida biofilm formation on venous catheters

INTRODUCTION

Infections associated with medical devices are often related to colonization by Candida spp. biofilm; in this way, numerous strategies have been developed and studied, mainly in order to prevent this type of fungal growth.

AIM

Considering the above, the main objective of the present study is to make a rational choice of the best antifungal therapy for the in vitro treatment of the biofilm on venous catheters, proposing an innovative formulation of a film-forming system to coat the surface in order to prevent the formation of biofilms.

METHODOLOGY

Anidulafungin, fluconazole, voriconazole, ketoconazole, amphotericin B, and the association of anidulafungin and amphotericin B were tested against biofilms of C. albicans, C. tropicalis, and C. parapsilosis strains in microtiter plates and in a polyurethane catheter. Besides, anidulafungin, amphotericin B, and the combination of both were incorporated in a film-forming system and were evaluated against biofilm.

RESULTS

The superior activity of anidulafungin was demonstrated in relation to the other antifungal agents. Although amphotericin B showed good activity, high concentrations were required. The combination showed a synergistic action, in solution and in the formulation, showing excellent results, with activity above 90%.

CONCLUSION

Due to the superiority of anidulafungin and the synergistic activity of the combination, these alternatives were the most promising options for use in a formulation proposal as a new strategy to combat the Candida spp. biofilm. These formulations demonstrated high in vitro performance in the prevention of biofilms, indicating that they are candidates with great potential for in vivo tests.

Premium ethylcellulose polymer based architectures at work in drug delivery

Premium ethylcellulose polymers are hydrophobic cellulose ether based biomaterials widely employed as biocompatible templates for the design of novel drug delivery systems. They are classified as United States Food and Drug Administration Generally-Recognized-As-Safe chemical substances and have been extensively utilized within the biomedical and pharmaceutical industries for over half a century. They have so far demonstrated the potential to modulate and improve the physiological performance of bioactives leading to the desired enhanced prophylactic and therapeutic outcomes. This review therefore presents a scholarly survey of inter-disciplinary developments focused on the functionalities of ethylcellulose polymers as biomaterials useful for the design of smart delivery architectures for relevant pharmacotherapeutic biomedical applications. Emphasis was placed on evaluating scientific resources related to recent advancements and future directions associated with its applications as delivery systems for drugs and biologics within the past decade thus complementing other specialized reviews showcasing the theme.

Ethylcellulose-A Pharmaceutical Excipient with Multidirectional Application in Drug Dosage Forms Development

Polymers constitute the most important group of excipients utilized in modern pharmaceutical technology, playing an essential role in the development of drug dosage forms. Synthetic, semisynthetic, and natural polymeric materials offer opportunities to overcome different formulative challenges and to design novel dosage forms for controlled release or for site-specific drug delivery. They are extensively used to design therapeutic systems, modify drug release, or mask unpleasant drug taste. Cellulose derivatives are characterized by different physicochemical properties, such as swellability, viscosity, biodegradability, pH dependency, or mucoadhesion, which determine their use in industry. One cellulose derivative with widespread application is ethylcellulose. Ethylcellulose is used in pharmaceutical technology as a coating agent, flavoring fixative, binder, filler, film-former, drug carrier, or stabilizer. The aim of this article is to provide a broad overview of ethylcellulose utilization for pharmaceutical purposes, with particular emphasis on its multidirectional role in the development of oral and topical drug dosage forms.

Sketching neoteric solvents for boosting drugs bioavailability

Emerging neoteric solvents are being the subject of growing attention due to their lower cost and environmental impact, so they are being applied in a broad spectrum of industries. Among them, the pharmaceutical sector is demanding new environmentally friendly and non-toxic solvents able to enhance drugs solubility and stability. The introduction of ionic liquids turned out to be a breakthrough in the field of Green Chemistry opening up new separation and catalysis opportunities. In this sense, the options represented by Deep Eutectic Solvents make up an attractive alternative due to the low cost of their raw material, simple synthesis, and eco-friendly character. In line with these findings, Therapeutic Deep Eutectic Solvents and Natural Deep Eutectic Solvents are new and promising alternatives to improve the bioavailability of drugs in pharmaceutical formulations. This leading article is focused on providing a general picture of the advantages and drawbacks of these new solvents as well as the main research lines and perspectives to achieve efficient drugs delivery systems.

Topical delivery of climbazole to mammalian skin

Dandruff is a common condition, affecting up to half the global population of immunocompetent adults at some time during their lives and it has been highly correlated with the over-expression of the fungus Malassezia spp. Climbazole (CBZ) is used as an antifungal and preservative agent in many marketed formulations for the treatment of dandruff. While the efficacy of CBZ in vitro and in vivo has previously been reported, limited information has been published about the uptake and deposition of CBZ in the skin. Hence, our aim was to investigate the skin permeation of CBZ as well as the influence of various solvents on CBZ skin delivery. Four solvents were selected for the permeability studies of CBZ, namely propylene glycol (PG), octyl salicylate (OSal), Transcutol® P (TC) and polyethylene glycol 200 (PEG). The criteria for selection were based on their wide use as excipients in commercial formulations, their potential to act as skin penetration enhancers and their favourable safety profiles. 1% (w/v) solutions of CBZ were applied under infinite and finite dose conditions using Franz type diffusion cells to human and porcine skin. In line with the topical use of CBZ as an antidandruff agent, comparatively low amounts of CBZ penetrated across the skin barrier (<1% of the applied dose of CBZ). Finite dose studies resulted in a higher extraction of CBZ from human skin compared with infinite dose studies (p < 0.05). CBZ was also taken up to a higher extent in porcine skin (>7-fold) compared with human skin (p < 0.05). Nevertheless, no statistical differences were observed in the amounts that permeated across the different membranes. These preliminary results confirm the potential of simple formulations of CBZ to target the outer layers of the epidermis. The PG and OSal formulations appear to be promising vehicles for CBZ in terms of overall skin extraction and penetration. Future work will expand the range of vehicles studied and explore the reasons underlying the retention of CBZ in the outer layers of the skin.

Microemulsions based on paeonol-menthol eutectic mixture for enhanced transdermal delivery: formulation development and in vitro evaluation

In this work, microemulsion-based gels were prepared for transdermal delivery of paeonol. Microemulsions containing eutectic mixtures of paeonol and menthol were developed. The obtained microemulsions were evaluated for particle size, viscosity and physical stability. The selected microemulsions were incorporated into Carbopol gels. Drug crystallization behavior during a short-term storage was compared and in vitro permeation and deposition study were conducted on mouse skin. Results showed that the eutectic liquids of paeonol and menthol at all ratio (6:4, 5:5 and 4:6) could form microemulsions but with significantly different physical characteristics. As the ratio of paeonol increased, the prepared microemulsions exhibited larger droplet size, higher viscosity and quicker crystal growth. Microemulsion containing paeonol and menthol at a ratio of 4:6 possessed the smallest size of 27 nm. Accordingly, the related gel showed better physical stability during 10 days of storage, as well as the highest percent of drug deposition (111.8 μg/cm²) and steady-state flux (0.3 μg/cm² h). These results suggested that the microemulsion formulation is a preferable approach for enhanced skin permeation, and the microemulsion based on drug-menthol eutectic mixture might be used as a potential transdermal delivery system for better therapeutic efficacy.