Novel Pemulen/Pullulan blended hydrogel containing clotrimazole-loaded cationic nanocapsules: Evaluation of mucoadhesion and vaginal permeation

Phase transforming in situ gels for sustained and controlled transmucosal drug delivery via the intravaginal route

Direct, reliable, controlled, and sustained drug delivery to female reproductive tract (FRT) remains elusive, with conventional dosage forms falling way short of the mark, leading to premature leakage, erratic drug delivery, and loss of compliance. Historically, the intravaginal route remains underserved by the pharmaceutical sector. To comprehensively address this, we turned our focus to phase-transforming sol-gels, using poloxamers, a thermosensitive polymer and, doxycycline (as hyclate salt, DOXH) as our model agent given its potential use in sexually transmitted infections (STIs). We further enhanced mucoadhesiveness through screening of differing viscosity grade hydroxypropyl methyl celluloses (HPMCs). The optimised sol-gels remained gelled at body temperature (<37 °C) and were prepared in buffer aligned to vaginal cavity pH and osmolality. Lead formulations were progressed based on their ability to retain key rheological properties, and acidic pH in the presence of simulated vaginal fluid (SVF). From a shelf-life perspective, DOXH stability, gelation temperature (Tsol-gel), and pH to three months (2-8 °C) was attained. In summary, the meticulously engineered, phase-transforming sol-gels provided sustained mucoretention despite dilution by vaginal fluid, paving the way for localised antimicrobial drug delivery at concentrations that potentially far exceed the minimum inhibitory concentration (MIC) for target STI-causing bacteria of the FRT.

Enhanced Solubility and Bioavailability of Clotrimazole in Aqueous Solutions with Hydrophobized Hyperbranched Polyglycidol for Improved Antifungal Activity

The poor solubility of clotrimazole in the aqueous medium and the uncontrolled removal of the drug-loaded suppository content limit its effectiveness in the treatment of vulvovaginal candidiasis. We present here the aqueous formulations of clotrimazole in the form of non-Newtonian structured fluids, i.e., Bingham plastic or pseudoplastic fluids constructed of hyperbranched polyglycidol, HbPGL, with a hydrophobized core with aryl groups such as phenyl or biphenyl. The amphiphilic constructs were obtained by the modification of linear units containing monohydroxyl groups with benzoyl chloride, phenyl isocyanate, and biphenyl isocyanate, while the terminal 1,2-diol groups in the shell were protected during the modification step, followed by their deprotection. The encapsulation of clotrimazole within internally hydrophobized HbPGLs using a solvent evaporation method followed by water addition resulted in structured fluids formation. Detailed Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) analyses performed for aryl-HbPGLs with clotrimazole revealed the difference in drug compatibility among polymers. Clotrimazole in biphenyl-enriched HbPGL, unlike phenyl derivatives, was molecularly distributed in both the dry and the hydrated states, resulting in transparent formulations. The shear-thinning properties of the obtained fluid formulations make them injectable and thus suitable for the intravaginal application. Permeability tests performed with the usage of the Franz diffusion cell showed a 5-fold increase in the permeability constant of clotrimazole compared to drugs loaded in a commercially available disposable tablet and a 50-fold increase of permeability in comparison to the aqueous suspension of clotrimazole. Furthermore, the biphenyl-modified HbPGL-based drug liquid showed enhanced antifungal activity against both Candida albicans and Candida glabrata that was retained for up to 7 days, in contrast to the phenyl-HbPGL derivatives and the tablet. With their simple formulation, convenient clotrimazole/biphenyl-HbPGL formulation strategy, rheological properties, and enhanced antifungal properties, these systems are potential antifungal therapeutics for gynecological applications. This study points in the synthetic direction of improving the solubility of poorly water-soluble aryl-enriched pharmaceuticals.

Nanotherapeutics for the delivery of antifungal drugs

The treatment of fungal infections is challenging with high death rates reported among immunocompromised patients. The currently available antifungals suffer from poor bioavailability and solubility, pharmacokinetics, and drug resistance, with limited cellular uptake. The clinical pipeline of new antifungals is dry. The incorporation of antifungal drugs into polymer-based nanocarriers to form nanotherapeutics is a promising approach to enhance the therapeutic outcomes of the available antifungal drugs. This review summarizes different polymer-based nanotherapeutics strategies that have been explored for the delivery of antifungals, resulting in enhanced therapeutic outcomes, such as improved pharmacokinetics, targeted/sustained delivery, prolonged drug circulation, retention of the drugs at the localized site of action, and overcoming drug resistance when compared with the free antifungal drugs.

Optimization of a Mucoadhesive Vaginal Gel Containing Clotrimazole Using a D-Optimal Experimental Design and Multivariate Analysis

The aim of this study was to develop a suitable clotrimazole (CLT)-loaded mucoadhesive vaginal gel (CLT-MVG) for topical applications in vaginal candidiasis. Ten CLT-MVG formulations were prepared, consisting of mixtures of acid polyacrylic (Carbopol 940) and polyethene oxides, Sentry Polyox WSRN 1105 or 750, according to an experimental D-optimal design, and CLT was suspended at a ratio of 1%. The prepared CLT-MVG formulations were studied in vitro, and the formulation containing Carbopol 940 0.89% combined with PEO 1105 1.39% was identified with the optimal rheological and in vitro bioadhesion properties, ensuring the prolonged release of CLT, with a similarity factor greater than 50, indicating dissolution profile similarity for three batches of the optimized formulation. This optimized formulation showed a pH in the tolerance range, and an adequate ex vivo mucoadhesion time, while the FT-IR studies revealed no interactions between the excipients and CLT. The microscopic analysis identified a mean particle size of suspended CLT of 5.24 ± 0.57 μm. The in vitro antifungal activity of the optimized formulation was tested on twenty strains of Candida albicans and proved to be better compared to a marketed clotrimazole preparation, showing a greater inhibition effect (p < 0.05). The optimized formulation could be a good candidate for the local treatment of vaginal mycosis.

A novel nanotechnological mucoadhesive and fast-dissolving film for vaginal delivery of clotrimazole: design, characterization, and in vitro antifungal action

Pullulan (PUL) films containing pomegranate seed oil and Eudragit^® RS100 nanocapsules loaded with clotrimazole (CTZ-NC-PUL) were developed to treat vulvovaginal candidiasis (VVC). Our findings showed that the nanocapsule average diameter was around 163 ± 4 nm, with polydispersity index values of up to 0.1 ± 0.01 and positively charged zeta potential (+ 43.5 ± 0.7 mV). The pH was in the acid range (5.14 ± 0.12) and encapsulation efficiency was around 99.6%; CTZ nanoencapsulation promoted higher homogeneity values for the film (91%), and the stability studies displayed no changes in the drug content after 120 days for the CTZ-NC-PUL under refrigerated conditions. All formulations were considered non-irritant, and CTZ-NC-PUL promoted a controlled release of the drug (60% in 24 h) compared to CTZ-PUL (100% in 8 h). The permeation results corroborate the drug release, where higher CTZ amounts were found in the mucosa and receptor medium for CTZ-PUL (21.02 and 4.46 μg/cm²). The films were fast dissolving (10 min), and CTZ-NC-PUL presented higher mucoadhesive properties; the antifungal activity against Candida albicans was maintained, and the in vitro efficacy of the film was proved. In conclusion, CTZ-NC-PUL formulation was considered promising and suitable for vaginal application against candida-related infections.

Polysaccharide-based hydrogels for drug delivery and wound management: a review

INTRODUCTION

Polysaccharide-based hydrogels (PBHs) offer several advantages over their synthetic counterparts. Their natural origin contributes to their nontoxicity, high biocompatibility, and in vivo biodegradability. Their properties can be tuned finely to obtain hydrogels with desired mechanical, structural, and chemical properties.

AREAS COVERED

Such versatile characteristics have potentiated the use of PBHs for the delivery of drugs, vaccines, protein and peptide therapeutics, genes, cells, probiotics, bacteriophages, and other therapeutic agents. Recent advances in hydrogel-based formulations such as nanogels, microgels, microneedles, hydrogel beads, nanocarrier-loaded hydrogels, and complexation hydrogels have enabled the precise delivery of a wide range of therapeutics. This review aims to give a holistic overview of hydrogels in the delivery of a variety of therapeutics through different routes.

EXPERT OPINION

PBHs have been used to enable the oral delivery of vaccines and other biologicals, thereby allowing self-administration of life-saving vaccines during public health emergencies. There is a lack of commercialized wound dressings for the treatment of chronic wounds. PBH-based wound dressings, especially those based on chitosan and loaded with actives and growth factors, have the potential to help in the long-term treatment of such wounds. Recent developments in the 3D printing of hydrogels can enable the quick and large-scale production of drug-loaded hydrogels.

Novel Pullulan/Gellan Gum Bilayer Film as a Vehicle for Silibinin-Loaded Nanocapsules in the Topical Treatment of Atopic Dermatitis

In this study a novel gellan gum/pullulan bilayer film containing silibinin-loaded nanocapsules was developed for topical treatment of atopic dermatitis (AD). The bilayer films were produced by applying a pullulan layer on a gellan gum layer incorporated with silibinin nanocapsules by two-step solvent casting method. The bilayer formation was confirmed by microscopic analysis. In vitro studies showed that pullulan imparts bioadhesitvity for the films and the presence of nanocapsules increased their occlusion factor almost 2-fold. Besides, the nano-based film presented a slow silibinin release and high affinity for cutaneous tissue. Moreover, this film presented high scavenger capacity and non-hemolytic property. In the in vivo study, interestingly, the treatments with vehicle film attenuated the scratching behavior and the ear edema in mice induced by 2,4-dinitrochlorobenzene (DNCB). However, the nano-based film containing silibinin modulated the inflammatory and oxidative parameters in a similar or more pronounced way than silibinin solution and vehicle film, as well as than hydrocortisone, a classical treatment of AD. In conclusion, these data suggest that itself gellan gum/pullulan bilayer film might attenuate the effects induced by DNCB, acting together with silibinin-loaded nanocapsules, which protected the skin from oxidative damage, improving the therapeutic effect in this AD-model.

Locust Bean Gum Nano-Based Hydrogel for Vaginal Delivery of Diphenyl Diselenide in the Treatment of Trichomoniasis: Formulation Characterization and In Vitro Biological Evaluation

Trichomoniasis is the most common nonviral sexually transmitted infection in the world, but its available therapies present low efficacy and high toxicity. Diphenyl diselenide (PhSe₂) is a pharmacologically active organic selenium compound; however, its clinical use is hindered by its lipophilicity and toxicity. Nanocarriers are an interesting approach to overcome the limitations associated with this compound. This study designed and evaluated a vaginal hydrogel containing PhSe₂-loaded Eudragit^® RS100 and coconut oil nanocapsules for the treatment of trichomoniasis. Nanocapsules presented particle sizes in the nanometric range, positive zeta potential, a compound content close to the theoretical value, and high encapsulation efficiency. The nanoencapsulation maintained the anti-Trichomonas vaginalis action of the compound while improving the scavenger action in a DPPH assay. The hydrogels were prepared by thickening nanocapsule suspensions with locust bean gum (3%). The semisolids maintained the nanometric size of the particles and the PhSe₂ content at around the initial concentration (1.0 mg/g). They also displayed non-Newtonian pseudo-plastic behavior and a highly mucoadhesive property. The chorioallantoic membrane method indicated the absence of hemorrhage, coagulation, or lysis. The compound, from both non-encapsulated and nano-based hydrogel delivery systems, remained on the surface of the bovine vaginal mucosa. Therefore, the formulations displayed the intended properties and could be a promising alternative for the treatment of trichomoniasis.

Development of a nanotechnological hydrogel containing desonide nanocapsules in association with acai oil: design and in vivo evaluation

Nanotechnological products have been used as strategies to optimize the therapy and minimize the side effects of topical corticoids. The objective of this study was to develop hydrogels by the addition of sclerotium gum to the suspensions of desonide-loaded açai oil-based nanocapsules and to study their biological effect using an animal model of acute skin inflammation. The hydrogels presented a pH compatible with topical application (4.4 to 5.0), nanometric mean diameter (131 to 165 nm), pseudoplastic behavior, and stability under room conditions during 30 days. The in vitro skin permeation/penetration study demonstrated that a higher amount of desonide (p < 0.05) was retained in the epidermis from the nanotechnological-hydrogels (0.33 to 0.36 µg.cm²) in comparison to the commercial gel cream (0.16 µg.cm²). In the dermis, the nanostructured hydrogels promoted a lower DES retention compared to the non-nanostructured formulations (p < 0.05). This result may indicate a smaller amount of drug reaching the bloodstream and, thus, fewer side effects can be expected. Concerning the anti-inflammatory effect, the developed hydrogels reduced both ear edema and inflammatory cell infiltration, showing an effect comparable to the commercially available formulation, which presents twice the drug concentration. The hydrogels developed may be considered a promising approach to treat dermatological disorders.

Carbohydrates Used in Polymeric Systems for Drug Delivery: From Structures to Applications

Carbohydrates, one of the most important compounds in living organisms, perform numerous roles, including those associated with the extracellular matrix, energy-related compounds, and information. Of these, polymeric carbohydrates are a class of substance with a long history in drug delivery that have attracted more attention in recent years. Because polymeric carbohydrates have the advantages of nontoxicity, biocompatibility, and biodegradability, they can be used in drug targeting, sustained drug release, immune antigens and adjuvants. In this review, various carbohydrate-based or carbohydrate-modified drug delivery systems and their applications in disease therapy have been surveyed. Specifically, this review focuses on the fundamental understanding of carbohydrate-based drug delivery systems, strategies for application, and the evaluation of biological activity. Future perspectives, including opportunities and challenges in this field, are also discussed.

Recent Advances in the Excipients Used in Modified Release Vaginal Formulations

The formulation of an ideal vaginal drug delivery system (DDS), with the requisite properties, with respect to safety, efficacy, patient compliance, aesthetics, harmonization with the regulatory requirements, and cost, requires a meticulous selection of the active ingredients and the excipients used. Novel excipients defined by diversity and multifunctionality are used in order to ameliorate drug delivery attributes. Synthetic and natural polymers are broadly used in pharmaceutical vaginal formulations (solid, semi-solid dosage forms, implantable devices, and nanomedicines) with a promising perspective in improving stability and compatibility issues when administered topically or systemically. Moreover, the use of biopolymers is aiming towards formulating novel bioactive, biocompatible, and biodegradable DDSs with a controllable drug release rate. Overviewing vaginal microenvironment, which is described by variable and perplexed features, a perceptive choice of excipients is essential. This review summarizes the recent advances on the excipients used in modified vaginal drug delivery formulations, in an attempt to aid the formulation scientist in selecting the optimal excipients for the preparation of vaginal products.

New Formulations Loading Caspofungin for Topical Therapy of Vulvovaginal Candidiasis

Vulvovaginal candidiasis (VVC) poses a significant problem worldwide affecting women from all strata of society. It is manifested as changes in vaginal discharge, irritation, itching and stinging sensation. Although most patients respond to topical treatment, there is still a need for increase the therapeutic arsenal due to resistances to anti-infective agents. The present study was designed to develop and characterize three hydrogels of chitosan (CTS), Poloxamer 407 (P407) and a combination of both containing 2% caspofungin (CSP) for the vaginal treatment of VVC. CTS was used by its mucoadhesive properties and P407 was used to exploit potential advantages related to increasing drug concentration in order to provide a local effect. The formulations were physically, mechanically and morphologically characterized. Drug release profile and ex vivo vaginal permeation studies were performed. Antifungal efficacy against different strains of Candida spp. was also evaluated. In addition, tolerance of formulations was studied by histological analysis. Results confirmed that CSP hydrogels could be proposed as promising candidates for the treatment of VVC.

Mucoadhesive gellan gum hydrogel containing diphenyl diselenide-loaded nanocapsules presents improved anti-candida action in a mouse model of vulvovaginal candidiasis

The aim of this study was to evaluate the in vitro antifungal action of a diphenyl diselenide-loaded poly(ε-caprolactone) nanocapsules suspension (NC-1) and incorporate it into a gellan gum hydrogel formulation in order to assess its in vivo efficacy in an animal model of vulvovaginal candidiasis. Nanocapsules suspensions containing the compound (NC-1 ∼ 5 mg/mL) or not (NC-B) were prepared by the interfacial deposition of preformed polymer method. To estimate in vitro antifungal effect, the broth microdilution test was applied. The results showed that NC-1 had equal or lower MIC values when compared to free compound against fifteen Candida strains. Following, the hydrogel was prepared by direct thickening of the nanocapsules suspension by gellan gum addition. The animal model of vulvovaginal candidiasis was induced by infecting female Swiss mice with Candida albicans strains. The animals were topically treated with 20 µL of hydrogels (NC-1 and free compound - 0.1 mg of diphenyl diselenide/once a day for seven days) and then the total fungal burden was assessed after the euthanasia. The results showed that the hydrogels presented pH in the acidic range, compound content close to theoretical value, homogeneous particle distribution with nanometric size, high physicochemical and microbiological stability as well as great bioadhesive property. The nano-based presented superior pharmacological action in comparison to the hydrogel containing non-encapsulated diphenyl diselenide. The results demonstrated that the nanoencapsulation maintained the effective antifungal action of diphenyl diselenide. The nano-based hydrogel formulation may be considered a promising approach against vulvovaginal candidiasis.

Pullulan film incorporated with nanocapsules improves pomegranate seed oil anti-inflammatory and antioxidant effects in the treatment of atopic dermatitis in mice

This study aimed to prepare pullulan films containing pomegranate seeds oil (PSO) based nanocapsules, and evaluate the formulation efficacy in the treatment of atopic dermatitis (AD)-like lesions induced by 2,4-dinitrochlorobenzene (DNCB). The Eudragit RS 100® nanocapsules (PSONC) were prepared by the interfacial precipitation of preformed polymer, whereas the films were produced by the solvent casting method. Pomegranate seed oil nanoemulsions (PSONE) were prepared by the spontaneous emulsification method for comparative reasons. Both nanosystems presented adequate mean diameter (248 ± 16 nm for PSONE and 181 ± 6 nm for PSONC), polydispersity index (below 0.2), zeta potential (-25.63 ± 1.1 mV for PSONE and + 43.13 ± 0.7 mV for PSONC) and pH in the acid range (6.77 ± 0.27 and 5.31 ± 0.17, PSONE and PSONC). By a pre-formulation study, sorbitol (6.5%) and PEG 400 (1.5%) were considered the most suitable plasticizers for developing pullulan films (6%) intending topical application. In general, pullulan films were classified as flexible and hydrophilic, with high occlusive properties, 57.6 ± 0.8%, 64.6 ± 0.8% for vehicle, PSONCF (pullulan film containing PSONC), respectively. All formulations (films and nanocarriers) presented no irritant potential in the chorioallantoic membrane test. In the in vivo model, the treatments with free PSO and PSONCF attenuated the skin injury as well as the mechanical hypernociceptive behavioral induced by DNCB exposure to mice. Importantly, the biochemical analyses provided evidence that only the treatment with PSONCF modulated the inflammatory and the oxidative stress parameters evaluated in this study. In conclusion, these data lead us to believe that PSONC incorporation into a pullulan film matrix improved the biological properties of the PSO in this AD-model.

Ferulic acid-loaded nanocapsules: Evaluation of mucosal interaction, safety and antioxidant activity in human mononucleated cells

Ferulic acid (FA) is a phenolic compound that has antioxidant, anti-inflammatory and anticarcinogenic properties besides presenting cytoprotective activity. It has limited oral bioavailability what is a challenge to its therapeutic application. In this way, this investigation aimed to develop FA-loaded nanocapsule suspensions (NC-FA) prepared with ethylcellulose and evaluate their in vitro release profile, mucoadhesion and irritation potential; scavenging capacity, cytotoxicity, cytoprotection and genoprotection against hydrogen peroxide-induced damage in hMNC (human Mononucleated Cells) culture. The nanocapsules presented physicochemical characteristics compatible with colloidal systems (NC-FA: 112 ± 3 nm; NC-B (without FA): 107 ± 3 nm; PdI < 0.2; Span<2.0 and negative zeta potential). In addition, the nanoparticulate system promoted the FA controlled release, increasing the half-life twice through the in vitro dialysis method. NC-FA and NC-B were able to interact with mucin, which is an indicative of mucoadhesive properties and the association of FA with nanocapsules showed decreased irritation by HET-CAM method. Besides, the NC-FA did not present cytotoxicity in hMNC and improved the ATBS radical scavenging capacity. Besides, it prevented, treated and reversed oxidative conditions in a H₂O₂-induced model in hMNC. Thus, this nanocarrier formulation is promising to perform more preclinical investigations focusing on diseases involving oxidative mechanisms.

Antimicrobial Polymer-Based Hydrogels for the Intravaginal Therapies-Engineering Considerations

The review is focused on the hydrogel systems dedicated to the intravaginal delivery of antibacterial, antifungal and anti-Trichomonas vaginalis activity drugs for the treatment of gynaecological infections. The strategies for the enhancement of the hydrophobic drug solubility in the hydrogel matrix based on the formation of bigel systems and the introduction of nano- and microparticles as a drug reservoir are presented. Hydrogel carriers of natural and synthetic pharmacological substances, drug-free systems displaying antimicrobial activity thanks to the hydrogel building elements and systems combining the antimicrobial activity of both drug and polymer building components are distinguished. The design of hydrogels facilitating their administration and proper distribution in the vaginal mucosa and the vagina based on thermoresponsive systems capable of gelling at vaginal conditions and already-cross-linked injectable systems after reaching the yield stress are discussed. In addition, the mechanisms of hydrogel bioadhesion that regulate the retention time in the vagina are indicated. Finally, the prospects for the further development of hydrogel-based drug carriers in gynaecological therapies are highlighted.

Pharmaceutical Approaches on Antimicrobial Resistance: Prospects and Challenges

The rapid increase in pathogenic microorganisms with antimicrobial resistant profiles has become a significant public health problem globally. The management of this issue using conventional antimicrobial preparations frequently results in an increase in pathogen resistance and a shortage of effective antimicrobials for future use against the same pathogens. In this review, we discuss the emergence of AMR and argue for the importance of addressing this issue by discovering novel synthetic or naturally occurring antibacterial compounds and providing insights into the application of various drug delivery approaches, delivered through numerous routes, in comparison with conventional delivery systems. In addition, we discuss the effectiveness of these delivery systems in different types of infectious diseases associated with antimicrobial resistance. Finally, future considerations in the development of highly effective antimicrobial delivery systems to combat antimicrobial resistance are presented.

Recent advances in hydrogels as strategy for drug delivery intended to vaginal infections

Vaginal infections represent a clear women health problem due to the several issues as high recurrence rate, drug resistence and emergence of persistent strains. However, achieving improvements in therapeutic efficacy by using conventional formulations intended to vaginal drug delivery remains as a challenge due to anatomy and physiology of the vagina, since the secretion and renewal of vaginal fluids contribute to the removal of the dosage form. Hydrogels have been widely exploited aiming to achieve drug delivery directly into vaginal mucosa for local therapy due to their attractive features as increased residence time of the drug at the action site and control of drug release rates. Some polymers can aggregate specific properties to hydrogels as mucoadhesive, stimuli-responsive and antimicrobial, improving their interaction with the biological interface and therapeutic response. In this review, we highlight the advances, advantages and challenges of the hydrogels as drug and/or nanocarrier vehicles intended to the treatment of vaginal infections, emphasizing also the polymers and their properties more explored on the design these systems to improve the therapeutic effect on the vaginal tissue. In addition, this review can contribute for better exploitation these systems in search of new local treatments for bacterial vaginosis, candidiasis and trichomoniasis.

Nanosystems against candidiasis: a review of studies performed over the last two decades

The crescent number of cases of candidiasis and the increase in the number of infections developed by non-albicans species and by multi-resistant strains has taken the attention of the scientific community, which has been searching for new therapeutic alternatives. Among the alternatives found the use of nanosystems for delivery of drugs already commercialized and new biomolecules have grown, in order to increase stability, solubility, optimize efficiency and reduce adverse effects. In view of the growing number of studies involving technological alternatives for the treatment of candidiasis, the present review came with the intention of gathering studies from the last two decades that used nanotechnology for the treatment of candidiasis, as well as analysing them critically and pointing out the future perspectives for their application with this purpose. Different studies were considered for the development of this review, addressing nanosystems such as metallic nanoparticles, mesoporous silica nanoparticles, polymeric nanoparticles, liposomes, nanoemulsion, microemulsion, solid lipid nanoparticle, nanostructured lipid carrier, lipidic nanocapsules and liquid crystals; and different clinical presentations of candidiasis. As a general overview, nanotechnology has proven to be an important ally for the treatment against the diversity of candidiasis found in the clinic, whether in increasing the effectiveness of commercialized drugs and reducing their adverse effects, as well as allowing exploring more effectively properties therapeutics of new biomolecules.

Recent Advances in Vaginal Delivery for the Treatment of Vulvovaginal Candidiasis

BACKGROUND

Vulvovaginal candidiasis (VVC) is a common vaginal infection caused by candida species, affecting 70% of the women. It may occur due to the imbalance in the vaginal micro- biodata, pregnancy, diabetes, use of antibiotics, frequent sexual activities or AIDS.

AIM

The main aim of this review is to provide overview about different vaginal delivery systems for the administration of antifungal agents like conventional, mucoadhesive and muco-penetrating delivery systems.

METHOD

The conventional delivery systems available have limited efficacy due to the less residence time and adverse effects. In order to overcome these issues, a delivery system with mucoadhesive and muco-penetrating properties is required. Mucoadhesive polymers have excellent binding properties with mucin and thus increasing residence time. On the other hand, muco-penetrating polymers transport the antifungal agents across the mucus layer.

RESULTS

This review summarizes the pathophysiology of VVC along with novel delivery systems for the treatment of infection through mucoadhesive and muco-penetrating approaches. Surface modifications of nano/ microparticles with mucoadhesive or muco-penetrating particles may provide delivery systems with improved therapeutic efficacy.

CONCLUSION

Based on the available data, conventional and mucoadhesive drug delivery systems have some limitations, they still require improvement/ development for safe and effective delivery of antifungal agents.

Gellan gum-based hydrogel containing nanocapsules for vaginal indole-3-carbinol delivery in trichomoniasis treatment

Trichomonas vaginalis infection is the STI most common worldwide. Indole-3-carbinol (I3C) is a phytochemical presenting promising biological activities. In this study, design, formulation, and evaluation of a vaginal hydrogel containing I3C-loaded nanocapsules for the treatment of trichomoniasis have been investigated. Nanocapsules of Eudragit® RS100 and rosehip oil containing I3C (NC-I3C) were prepared by interfacial deposition of preformed polymer method. In vitro evaluations showed that free I3C (IC50 = 3.36 µg/mL) was able to reduce the trophozoites viability at higher concentrations (3.13 and 6.25 µg/mL), while nanoencapsulation (IC50 = 2.09 µg/mL) reduced the viability at all concentrations evaluated. Comparing free and nanoencapsulated I3C, we observe that nanoencapsulation improved anti-T. vaginalis activity. In order to obtain a formulation for vaginal administration, hydrogels (HG-NC-I3C) were prepared by thickening the NC-I3C with gellan gum. HG-NC-I3C presented particle size below 195 nm, low polydispersity index (<0.2), I3C content = 0.50 ± 0.01 mg/g, pH = 7.05, non-Newtonian pseudoplastic flow behavior and exhibited mucoadhesion to cow's vaginal mucosa. Evaluation of irritation potential by chorioallantoic membrane method indicated that the formulations are considered non-irritating. Besides that, permeation through the cow's vaginal mucosa showed that nanoencapsulation promoted I3C controlled release. This way, the developed HG-NC-I3C can be considered a promising approach for trichomoniasis treatment through vaginal administration.

Formulation, development, and in-vitro/ex-vivo evaluation of vaginal bioadhesive salbutamol sulfate tablets for preterm labor

Preterm labor is the main cause of death and serious illness of both infants and pregnant women in Africa and worldwide. Parenteral and oral salbutamol sulfate as a B₂ antagonist has been used for the treatment of preterm labor. The study aims are to formulate salbutamol sulfate non-invasive vaginal bioadhesive tablets to avoid the side effects of conventional formulations. Full factorial design 4¹ ×3¹ ×2¹ was used for the preparation of 24 vaginal bioadhesive tablet formulations. The independent factors were polymer type (Carbopol 934, HPMC 4000, HEC, and PEG 6000), polymer to drug ratio (1:1, 2:1, and 3:1), and diluent (lactose and mannitol). Vaginal bioadhesive tablets were evaluated for residence time and time required for release 50% of salbutamol sulfate T_50% as dependent variables. The formulations were evaluated in terms of drug content, mass variation, hardness, friability, swelling index, residence time, and in-vitro drug release. Results revealed that polymer and diluent types are the most significant factors in both residence time and T_50%. A strong positive correlation (0.91) between in-vitro and ex-vivo permeation was observed, which predict the best in-vivo performance of salbutamol vaginal bioadhesive tablet. Thus, salbutamol sulfate vaginal bioadhesive tablets could be a successful remedy for preterm labor.

Challenges and Recent Progress in Oral Drug Delivery Systems for Biopharmaceuticals

Routes of drug administration and the corresponding physicochemical characteristics of a given route play significant roles in therapeutic efficacy and short term/long term biological effects. Each delivery method has favorable aspects and limitations, each requiring a specific delivery vehicles design. Among various routes, oral delivery has been recognized as the most attractive method, mainly due to its potential for solid formulations with long shelf life, sustained delivery, ease of administration and intensified immune response. At the same time, a few challenges exist in oral delivery, which have been the main research focus in the field in the past few years. The present work concisely reviews different administration routes as well as the advantages and disadvantages of each method, highlighting why oral delivery is currently the most promising approach. Subsequently, the present work discusses the main obstacles for oral systems and explains the most recent solutions proposed to deal with each issue.

Continuous manufacturing of orally dissolving webs containing a poorly soluble drug via electrospinning

An orally dissolving web (ODW) formulation of poorly soluble carvedilol (CAR) was developed and manufactured continuously using electrospinning (ES) as a key technology. Phase solubility tests revealed that hydroxypropyl-β-cyclodextrin (HPβCD) solubilizer alone cannot ensure sufficient solubility (6.25 mg CAR in 20 mL) in the oral cavity even if citric acid was present to ionize the basic drug. In turn, electrospun amorphous nanofibers of polyvinylpyrrolidone K30 (PVPK30) and CAR exhibited notable supersaturation of the drug in the presence of citric acid. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) confirmed the amorphous state of CAR. The final ODW was prepared by layering the nanofibers onto pullulan, a well-soluble polysaccharide film carrying citric acid. The double-layered formulation showed ultrafast disintegration and dissolution modeling the oral cavity meeting regulatory requirements (<30 s). The continuous production was accomplished using our recently developed continuous model system by controlled deposition of the nanofibers onto the carrier film strained to a wheel collector and followed by cutting into final dosage units. Performance tests of the continuous system revealed satisfactory content uniformity over time (average acceptance value = 9.45), while residual solvent content measurements showed trace amounts of ethanol (EtOH) after production and acceptable dimethyl-formamide (DMF) content with secondary drying at room temperature. The presented work demonstrates how ES can be part of a continuous manufacturing system as an advanced drying tool during the formulation of challenging drugs.

Approaches in Polymeric Nanoparticles for Vaginal Drug Delivery: A Review of the State of the Art

The vagina is a region of administration with a high contact surface to obtain local or systemic effects. This anatomical area represents special interest for government health systems for different sexually transmitted infections. However, the chemical changes of the vagina, as well as its abundant mucus in continuous exchange, act as a barrier and a challenge for the development of new drugs. For these purposes, the development of new pharmaceutical forms based on nanoparticles has been shown to offer various advantages, such as bioadhesion, easy penetration of the mucosa, and controlled release, in addition to decreasing the adverse effects of conventional pharmaceutical forms. In order to obtain nanoparticles for vaginal administration, the use of polymers of natural and synthetic origin including biodegradable and non-biodegradable systems have gained great interest both in nanospheres and in nanocapsules. The main aim of this review is to provide an overview of the development of nanotechnology for vaginal drug release, analyzing the different compositions of polymeric nanoparticles, and emphasizing new trends in each of the sections presented. At the end of this review, a section analyzes the properties of the vehicles employed for the administration of nanoparticles and discusses how to take advantage of the properties that they offer. This review aims to be a reference guide for new formulators interested in the vaginal route.