Vaginal mucoadhesive drug delivery systems

Pharmabiotic/phytobiotic formulas approach and their intravaginal effect on different parameters

Postpartum reproductive infections in cows generate significant economic losses. The use of lactic acid bacteria in animal health is an alternative tool to avoid antibiotic therapy in the prevention/treatment of bovine reproductive infections. In previous studies, 6 lactic bacteria from bovine mammary glands and vagina with beneficial, safe and technological characteristics were selected, and included in probiotic/phytobiotic formulas (combined with Malva and Lapacho extracts). In this work, probiotic and phytobiotic formulations were designed and their long-term viability determined. They were administered intravaginally to 30 females pregnant bovine pre and postpartum. The modification of the native microbiota and permanence/colonization of cultivable bacteria was evaluated, and also the safety of the designed products through the application of nutritional, clinical, hematological and biochemical parameters. The microorganisms maintained their viability up to 9 months at refrigeration temperature. The number of cultivable bacteria showed different pattern: total aerobic mesophylls increased slightly in all experimental groups, while Enterobacteriaceae increased after delivery, except in beneficial acid lactic bacteria + vegetable extract cows. Control and vegetable extract females showed the highest numbers of Enterobacteriaceae at the end of the trial (30 days postpartum). The number of lactic acid bacteria increased significantly in all the groups between 15 days pre and postpartum. The different parameters evaluated demonstrate the safety and harmlessness of the designed formulas, without producing local and systemic adverse effects in the cows.

Imiquimod-Loaded Nanosystem for Treatment Human Papillomavirus-Induced Lesions

Human papillomavirus (HPV)-associated cervical cancer is the most common cancer among women worldwide. The treatment options are strongly related to increased infertility in women. Imiquimod (IQ) is an imidazoquinoline, which has proven antiviral effects against persistent HPV infection by activating immune cells via Toll-like receptors 7/8 when formulated in carriers, like nanogels, for topical use. An effective alternative to conventional therapies is the nanoparticle drug delivery system. We studied lipidic nanoparticles with IQ (Lipo IQ) and functionalized them with a DNA aptamer, AT11 (Lipo IQ AT11), to improve the selectivity for cervical cancer cells combined with the efficacy of essential oils. The formulations showed that the physicochemical properties are adequate for vaginal drug delivery and have antimicrobial activity at higher concentrations (with MIC50 starting from 0.625%). The final formulations exhibited cytotoxicity in cancer cells, enhanced by essential oils without affecting healthy cells, resulting in less than 10% cell viability in HeLa cells and over 60% in NHDF cells. Essential oils potentiate Lipo IQ's effectiveness, while AT11 increases the selectivity for cervical cancer cells. As suggested by the results of the permeation assay, the formulations were internalized by the cancer cells. Overall, the obtained results suggested that the synergistic effect of the essential oils and the nanosystem potentiate the cytotoxic effect of Lipo IQ and that Lipo IQ AT11 promotes selectivity towards cancer cells.

Novel Drug Delivery Approaches for the Localized Treatment of Cervical Cancer

Cervical cancer (CC) is the fourth leading cancer type in females globally. Being an ailment of the birth canal, primitive treatment strategies, including surgery, radiation, or laser therapy, bring along the risk of infertility, neonate mortality, premature parturition, etc. Systemic chemotherapy led to systemic toxicity. Therefore, delivering a smaller cargo of therapeutics to the local site is more beneficial in terms of efficacy as well as safety. Due to the regeneration of cervicovaginal mucus, conventional dosage forms come with the limitations of leaking, the requirement of repeated administration, and compromised vaginal retention. Therefore, these days novel strategies are being investigated with the ability to combat the limitations of conventional formulations. Novel carriers can be engineered to manipulate bioadhesive properties and sustained release patterns can be obtained thus leading to the maintenance of actives at therapeutic level locally for a longer period. Other than the purpose of CC treatment, these delivery systems also have been designed as postoperative care where a certain dose of antitumor agent will be maintained in the cervix postsurgical removal of the tumor. Herein, the most explored localized delivery systems for the treatment of CC, namely, nanofibers, nanoparticles, in situ gel, liposome, and hydrogel, have been discussed in detail. These carriers have exceptional properties that have been further modified with the aid of a wide range of polymers in order to serve the required purpose of therapeutic effect, safety, and stability. Further, the safety of these delivery systems toward vital organs has also been discussed.

Commercial hydrogel product for drug delivery based on route of administration

Hydrogels are hydrophilic, three-dimensional, cross-linked polymers that absorb significant amounts of biological fluids or water. Hydrogels possess several favorable properties, including flexibility, stimulus-responsiveness, versatility, and structural composition. They can be categorized according to their sources, synthesis route, response to stimulus, and application. Controlling the cross-link density matrix and the hydrogels' attraction to water while they're swelling makes it easy to change their porous structure, which makes them ideal for drug delivery. Hydrogel in drug delivery can be achieved by various routes involving injectable, oral, buccal, vaginal, ocular, and transdermal administration routes. The hydrogel market is expected to grow from its 2019 valuation of USD 22.1 billion to USD 31.4 billion by 2027. Commercial hydrogels are helpful for various drug delivery applications, such as transdermal patches with controlled release characteristics, stimuli-responsive hydrogels for oral administration, and localized delivery via parenteral means. Here, we are mainly focused on the commercial hydrogel products used for drug delivery based on the described route of administration.

Nanomaterials Solutions for Contraception: Concerns, Advances, and Prospects

Preventing unintentional pregnancy is one of the goals of a global public health policy to minimize effects on individuals, families, and society. Various contraceptive formulations with high effectiveness and acceptance, including intrauterine devices, hormonal patches for females, and condoms and vasectomy for males, have been developed and adopted over the last decades. However, distinct breakthroughs of contraceptive techniques have not yet been achieved, while the associated long-term adverse effects are insurmountable, such as endocrine system disorder along with hormone administration, invasive ligation, and slowly restored fertility after removal of intrauterine devices. Spurred by developments of nanomaterials and bionanotechnologies, advanced contraceptives could be fulfilled via nanomaterial solutions with much safer and more controllable and effective approaches to meet various and specific needs for women and men at different reproductive stages. Nanomedicine techniques have been extended to develop contraceptive methods, such as the targeted drug delivery and controlled release of hormone using nanocarriers for females and physical stimulation assisted vasectomy using functional nanomaterials via photothermal treatment or magnetic hyperthermia for males. Nanomaterial solutions for advanced contraceptives offer significantly improved biosafety, noninvasive administration, and controllable reversibility. This review summarizes the nanomaterial solutions to female and male contraceptives including the working mechanisms, clinical concerns, and their merits and demerits. This work also reviewed the nanomaterials that have been adopted in contraceptive applications. In addition, we further discuss safety considerations and future perspectives of nanomaterials in nanostrategy development for next-generation contraceptives. We expect that nanomaterials would potentially replace conventional materials for contraception in the near future.

Design of a pilot plant-type pharmaceutical reactor to address the problem of interchangeability of generic semisolid formulations

OBJECTIVE AND SIGNIFICANCE

This research aims to design and develop a pilot plant-type pharmaceutical reactor with a strong focus on its volumetric capacity and heat transfer capabilities. The primary goal is to replicate design and control strategies at the laboratory or pilot scale to analyze and produce generic semisolid formulations.

METHODS

Computational fluid dynamics and heat transfer modeling, utilizing the finite volume method, were employed to determine the reactor's performance and particle trajectory during the mixing and stirring. This allowed for the establishment of optimal operational parameters and variables. Furthermore, prototypes were constructed at 1:2.5 and 1:15 scales to examine the reactor's morphology, ensure volumetric versatility, and conduct mixing, homogenization, and coloration tests using varying volumes.

RESULTS AND CONCLUSIONS

The outcomes of this study yielded a versatile reactor suitable for processing pharmaceutical semisolids at both laboratory and pilot-scale volumes. Notably, the reactor demonstrated exceptional volumetric capacity within a single vessel while effectively facilitating heat transfer to its interior.

Formulation and characterization of pressure-assisted microsyringe 3D-printed scaffolds for controlled intravaginal antibiotic release

Bacterial vaginosis (BV) is a highly recurrent vaginal condition linked with many health complications. Topical antibiotic treatments for BV are challenged with drug solubility in vaginal fluid, lack of convenience and user adherence to daily treatment protocols, among other factors. 3D-printed scaffolds can provide sustained antibiotic delivery to the female reproductive tract (FRT). Silicone vehicles have been shown to provide structural stability, flexibility, and biocompatibility, with favorable drug release kinetics. This study formulates and characterizes novel metronidazole-containing 3D-printed silicone scaffolds for eventual application to the FRT. Scaffolds were evaluated for degradation, swelling, compression, and metronidazole release in simulated vaginal fluid (SVF). Scaffolds retained high structural integrity and sustained release. Minimal mass loss (<6%) and swelling (<2%) were observed after 14 days in SVF, relative to initial post-cure measurements. Scaffolds cured for 24 hr (50 °C) demonstrated elastic behavior under 20% compression and 4.0 N load. Scaffolds cured for 4 hr (50 °C), followed by 72 hr (4 °C), demonstrated the highest, sustained, metronidazole release (4.0 and 27.0 µg/mg) after 24 hr and 14 days, respectively. Based upon daily release profiles, it was observed that the 24 hr timepoint had the greatest metronidazole release of 4.08 μg/mg for scaffolds cured at 4 hr at 50 °C followed by 72 hr at 4 °C. For all curing conditions, release of metronidazole after 1 and 7 days showed > 4.0-log reduction in Gardnerella concentration. Negligible cytotoxicity was observed in treated keratinocytes comparable to untreated cells, This study shows that pressure-assisted microsyringe 3D-printed silicone scaffolds may provide a versatile vehicle for sustained metronidazole delivery to the FRT.

Nose-to-brain delivery of galantamine loaded nanospray dried polyacrylic acid/taurodeoxycholate mixed matrix as a protective therapy in lipopolysaccharide-induced Alzheimer's in mice model

One of the promising drug delivery approaches is performed by nanosizing the administered drug product using the nanospray drying technique. In this study, a combination of several formulation factors was integrated and exploited to augment the bioavailability of galantamine hydrobromide (GAL) via the intranasal route. Nanosized polymeric particles were fabricated using the mucoadhesive polymer, polyacrylic acid (PAA), and the permeability booster, sodium taurodeoxycholate (TDC). First, a preliminary study was conducted to adjust the nanospray drying conditions. Then, formulations were prepared on the basis of a mixed factorial experimental design and further analyzed using Design Expert® software. Different responses were investigated: particle size, polydispersity index, spray rate, drying efficiency, and percent yield. The optimized formulation was further assessed for physical morphology using the scanning electron microscope, flowability, in vitro drug release, and in vivo brain cell uptake using confocal laser scanning microscopy. The promising formulation (F6), composed of equal ratio of PAA and TDC and 20 mg GAL, exhibited a particle size of 185.55 ± 4.3 nm, polydispersity index of 0.413 ± 0.02, and yield-value of 69.58 ± 5.82 %. It also displayed good flowability, complete drug release within 2 h, and enhanced in vivo fluorescent dye uptake and penetration in brain cells. The efficacy of the optimized formulation was examined using lipopolysaccharide-induced Alzheimer's in mice. Results revealed the advantageous influence of the optimized formulation (F6) through downregulation of NF-κβ, IL-1β and GFAP as well as upregulating TGF-1β in adult mice.

Advanced Solid Formulations For Vulvovaginal Candidiasis

Vulvovaginal candidiasis (VVC) is an opportunistic and endogenous infection caused by a fungus of the Candida genus, which can cause pruritus, dysuria, vulvar edema, fissures and maceration of the vulva. The treatment of vaginal candidiasis is carried out mainly by antifungal agents of azole and polyene classes; however, fungal resistance cases have been often observed. For this reason, new therapeutic agents such as essential oils, probiotics and antimicrobial peptides are being investigated, which can be combined with conventional drugs. Local administration of antimicrobials has also been considered to allow greater control of drug delivery and reduce or avoid undesirable systemic adverse effects. Conventional dosage forms such as creams and ointments result in reduced residence time in the mucosa and non-sustained and variable drug delivery. Therefore, advanced solid formulations such as intravaginal rings, vaginal films, sponges and nanofibers have been purposed. In these systems, polymers in different ratios are combined aiming to achieve a specific drug release profile and high mucoadhesion. Overall, a more porous matrix structure leads to a higher rate of drug release and mucoadhesion. The advantages, limitations and technological aspects of each dosage form are discussed in detail in this review.

A systematic review of mucoadhesive vaginal tablet testing

Drug administration through the vaginal tract is one of the oldest modalities of pharmacotherapy, and it is also one of the most explored. Since the vaginal cavity has a wide surface area, a plentiful blood supply, and a complex network of blood arteries, it can evade hepatic first-pass metabolism and obtain high local drug concentrations. Vaginal pills look to be a good dose form since they are simple to use, portable, and can easily deliver the required amount of medicine. Vaginal formulations, on the other hand, are vulnerable to rapid expulsion due to the vaginal tract’s self-cleaning action, which reduces the formulation’s efficiency. Currently, there is an increasing amount of focus on mucoadhesive vaginal formulation research and development to fix the formulation at the place where the medicine can be released and/or absorbed. This article examines all of the strategies used by researchers to develop a mucoadhesive vaginal tablet that is safe, effective, and comfortable for the user.

Formulation and In Vitro Evaluation of Mucoadhesive Sustained Release Gels of Phytoestrogen Diarylheptanoids from Curcuma comosa for Vaginal Delivery

Diarylheptanoids (DAs) characterized by a 1,7-diphenylheptane structural skeleton are considered a novel class of phytoestrogens. The DAs available in Curcuma comosa Roxb. (C. comosa) extract demonstrated significant estrogenic activities both in vitro and in vivo. This study aimed to develop and comprehensively evaluate a mucoadhesive vaginal gel for the sustained release of DAs. Different mucoadhesive polymers as gelling agents were investigated. C. comosa ethanolic crude extract was used as a source of DAs. All C. comosa gels were light brown homogeneous with pH within 4.4-4.6. Their flow behaviors were pseudoplastic with a flow behavior index of 0.18-0.38. The viscosity at a low shear rate varied from 6.2 to 335.4 Pa·s. Their mechanical and extrudability properties were associated well with rheological properties. Polycarbophil (PCP):hydroxypropyl methylcellulose (HPMC) blends had a higher mucoadhesiveness to porcine vaginal mucosa than those of PCP-based or HPMC-based gels. All C. comosa gels exhibited a sustained, zero-order DA release pattern over 72 h. Korsmeyer and Peppas equation fitting indicated a non-Fickian, case II transport release mechanism. C. comosa gels had good physical and chemical stability under low-temperature storage for up to 12 months. PCP:HPMC-based mucoadhesive gels could be a proper delivery system for vaginal administration of DAs.

Effects of intravaginal administration of prostaglandin F2α on luteolysis and subsequent estrus in Shiba goats (Capra hircus)

This study examined the effects of intravaginal administration of prostaglandin F2α (PGF2α ) on luteolysis and subsequent estrus in cycling goats. Goats with functional corpus lutea received one of five treatments: 2 mg of PG intramuscularly (IM2 × 1; n = 6), 2 mg of PGF2α intravaginally (IVG2 × 1; n = 7), 4 mg of PGF2α intravaginally (IVG4 × 1; n = 7), and 1 or 2 mg of PGF2α intravaginally 8 h apart (IVG1 × 2 group; n = 6 and IVG2 × 2; n = 8). Blood samples were collected at 24-h intervals from 0 to 7 days after PGF2α administration. Estrus was checked twice daily during the experiment. The proportion of goats with complete luteolysis (reduction of progesterone concentrations to <1 ng/mL until 48 h after treatment) in the IVG2 × 1 group (28.6%) was significantly lower than in the other groups (IM2 × 1; 100%, IVG4 × 1; 57.1%, IVG1 × 2; 87.5%, IVG2 × 2; 100%, respectively). For goats completing luteolysis, there was no significant difference in the onset and duration of estrus among the groups. These results suggest that intravaginal administration of PGF2α can be applied as an alternative to intramuscular administration.

Novel Mucoadhesive Wafers for Treating Local Vaginal Infections

Current vaginal formulations, such as gels and pessaries, have limitations, including poor retention. Therefore, the use of mucoadhesive formulations that adhere to the vaginal wall would allow prolonged retention and controlled drug release while reducing the required dose and the potential toxicity associated with high drug loading. The aim of the current research was to develop, characterize, and optimize freeze-dried wafers loaded with metronidazole (MTz) to treat vaginal bacterial infections. Blank (BLK) composite wafers comprising carrageenan (CARR) and sodium alginate (SA) were initially formulated; however, due to poor physico-chemical properties, Carbopol (CARB), hydroxypropylmethylcellulose (HPMC), and polyethylene glycol 200 (PEG) were included. The MTz-loaded formulations were obtained by loading optimized composite CARB:CARR- or CARB:SA-based gels (modified with HPMC and/or PEG) with 0.75% of MTz prior to freeze-drying. The physico-chemical properties were investigated using texture analysis (resistance to compressive deformation and adhesion), scanning electron microscopy (SEM), X-ray diffractometry (XRD), and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy. Functional properties were investigated by examining the swelling, porosity, drug release, and in vitro antimicrobial activity using E. coli as a model infection-causative agent. The results showed that HPMC and PEG generally improved the wafer's appearance, with smoother surfaces for easy insertion. From the physico-chemical characterization studies, only two composite wafers prepared from 8% CARB:SA 1:4 and 8% CARB:SA 1:9 gels were deemed optimal and loaded with MTz. Both formulations showed sustained drug release and achieved almost 100% cumulative release within 72 h in simulated vaginal fluid. The data obtained from the drug dissolution (release) experiments were fitted to various mathematical equations and showed the highest correlation coefficient with the Higuchi equation, suggesting a drug release based on diffusion from a swollen matrix; this was confirmed by the Korsmeyer-Peppas equation. The released MTz inhibited the growth of the E. coli used as a model bacterial organism.

Development of Novel S-Protective Thiolated-Based Mucoadhesive Tablets for Repaglinide: Pharmacokinetic Study

Mucoadhesive polymers have an essential role in drug localization and target-specific actions in oral delivery systems. The current work aims to develop and characterize a new mucoadhesive polysaccharide polymer (thiolated xanthan gum-TXG and S-Protected thiolated xanthan gum-STX) that was further utilized for the preparation of repaglinide mucoadhesive tablets. The thiolation of xanthan gum was carried out by ester formation through the reaction of the hydroxyl group of xanthan gum and the carboxyl group of thioglycolic acid. Synthesis of TXG was optimized using central composite design, and TXG prepared using 5.303 moles/L of TGA and 6.075 g/L of xanthan gum can accomplish the prerequisites of the optimized formulation. Consequently, TXG was further combined with aromatic 2-mercapto-nicotinic acid to synthesize STX. TXG and STX were further studied for Fourier-transform infrared spectroscopy, rheological investigations, and Ellman’s assay (to quantify the number of thiol/disulfide groups). A substantial rise in the viscosity of STX might be due to increased interactions of macromolecules liable for improving the mucosal adhesion strength of thiolated gum. STX was proven safe with the support of cytotoxic study data. Mucoadhesive formulations of repaglinide-containing STX showed the highest ex vivo mucoadhesion strength (12.78 g-RSX-1 and 17.57 g- RSX-2) and residence time (>16 h). The improved cross-linkage and cohesive nature of the matrix in the thiolated and S-protected thiolated formulations was responsible for the controlled release of repaglinide over 16 h. The pharmacokinetic study revealed the greater AUC (area under the curve) and long half-life with the RSX-2 formulation, confirming that formulations based on S-protected thiomers can be favorable drug systems for enhancing the bioavailability of low-solubility drugs.

Thermosensitive gel based on cellulose derivative for topical delivery of propolis in acne treatment

Thermosensitive bioadhesive formulations can display increased retention time, skin permeation, and improve the topical therapy of many drugs. Acne is an inflammatory process triggered by several factors like the proliferation of the bacteria Propionibacterium acnes. Aiming a new alternative treatment with a natural source, propolis displays great potential due to its antibiotic, anti-inflammatory and healing properties. This study describes the development of bioadhesive thermoresponsive platform with cellulose derivatives and poloxamer 407 for propolis skin delivery. Propolis ethanolic extract (PES) was added to the formulations with sodium carboxymethylcellulose (CMC) or hydroxypropyl methylcellulose (HPMC) and poloxamer 407 (Polox). The formulations were characterized as rheology, bioadhesion and mechanical analysis. The selected formulations were investigated as in vitro propolis release, cytotoxicity, ex vivo skin permeation by Fourier Transform Infrared Photoacoustic Spectroscopy, and the activity against P. acnes. Formulations showed suitable sol-gel transition temperature, shear-thinning behavior and texture profile. CMC presence decreased cohesiveness and adhesiveness of formulations. Polox/HPMC/PES system displayed less cytotoxicity, modified propolis release governed by anomalous transport, skin permeation and activity against P. acnes. These results indicate important advantages in the topical treatment of acne and suggest a potential formulation for clinical evaluation.

A Three-Dimensional Printable Hydrogel Formulation for the Local Delivery of Therapeutic Nanoparticles to Cervical Cancer

Cervical cancer is the fourth most common malignancy among women. Compared to other types of cancer, therapeutic agents can be administrated locally at the mucosal vaginal membrane. Thermosensitive gels have been developed over the years for contraception or for the treatment of bacterial, fungal, and sexually transmitted infections. These formulations often carry therapeutic nanoparticles and are now being considered in the arsenal of tools for oncology. They can also be three-dimensionally (3D) printed for a better geometrical adjustment to the anatomy of the patient, thus enhancing the local delivery treatment. In this study, a localized delivery system composed of a Pluronic F127-alginate hydrogel with efficient nanoparticle (NP) release properties was prepared for intravaginal application procedures. The kinetics of hydrogel degradation and its NP releasing properties were demonstrated with ultrasmall gold nanoparticles (∼80% of encapsulated AuNPs released in 48 h). The mucoadhesive properties of the hydrogel formulation were assayed by the periodic acid/Schiff reagent staining, which revealed that 19% of mucins were adsorbed on the gel's surface. The hydrogel formulation was tested for cytocompatibility in three cell lines (HeLa, CRL 2616, and BT-474; no sign of cytotoxicity revealed). The release of AuNPs from the hydrogel and their accumulation in vaginal membranes were quantitatively measured in vitro/ex vivo with positron emission tomography, a highly sensitive modality allowing real-time imaging of nanoparticle diffusion (lag time to start of permeation of 3.3 h, 47% of AuNPs accumulated in the mucosa after 42 h). Finally, the potential of the AuNP-containing Pluronic F127-alginate hydrogel for 3D printing was demonstrated, and the geometrical precision of the 3D printed systems was measured by magnetic resonance imaging (<0.5 mm precision; deviation from the design values <2.5%). In summary, this study demonstrates the potential of Pluronic F127-alginate formulations for the topical administration of NP-releasing gels applied to vaginal wall therapy. This technology could open new possibilities for photothermal and radiosensitizing oncology applications.

A mucoadhesive biodissolvable thin film for localized and rapid delivery of lidocaine for the treatment of vestibulodynia

Vestibulodynia (VBD), an idiopathic pain disorder characterized by erythema and pain of the vulvar vestibule (the inner aspect of the labia minora and vaginal opening), is the most common cause of sexual pain for women of reproductive age. Women also feel discomfort with contact with clothing and tampon use. As most women with this disorder only have pain with provocation of the tissue, topical anesthetics applied to the vestibule are the current first line treatment for temporary pain relief. Treatment options are limited due to anatomical constraints of the vestibular region, poor drug retention time, imprecise dosing, leakage, and overall product messiness. In this study we report a novel approach to treatment of VBD using thin film designed to fit the vulvar vestibule and deliver lidocaine locally. Two use cases for VBD treatment were identified 1) rapid drug release (<5 min), for use prior to intercourse and 2) long-acting release (≥120 min) for prolonged use and relief throughout the day. Cellulose-based mucoadhesive thin films were fabricated using a solvent casting method. Three polymers including hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), and hydroxypropylmethycellulose (HMPC), were selected owing to their biocompatibility and ideal properties for film casting. Films casted with HEC, HPC, and HPMC exhibited mucoadhesive properties relative to a control, with the highest mucoadhesive force recorded for films casted with HPC. Effect of media volume, pH, presence of mucin and presence of drug on film dissolution rates were investigated. Dissolution rates were independent of media volume, media pH or drug presence, whereas faster dissolution rates were obtained for all films in presence of mucin. In vitro lidocaine release kinetics were influenced by polymer type, percent drug loading and film casting thickness. Lidocaine release was based on a diffusion mechanism rather than through film dissolution and faster release (∼5 min) was observed for HEC films compared HPC films (∼120 min). Higher drug loading and film thickness resulted in slower and more prolonged release kinetics of lidocaine. All films were biocompatible and exhibited good mechanical properties. Two film formulations (9% w/w HPC with 12% w/w LHC, 5% w/w HEC with 6% w/w LHC) were optimized to meet the two use case scenarios for VBD treatment and moved into in vivo testing. In vivo testing demonstrated the safety of the films in BALB/c mice, and the pharmacokinetic analysis demonstrated the delivery of lidocaine primarily to the vaginal tissue. We demonstrate the ability to develop a mucoadhesive, biodissolvable thin film and fine-tune drug release kinetics to optimize local delivery of lidocaine to the vulva.

Development of thermosensitive and mucoadhesive gels of cabotegravir for enhanced permeation and retention profiles in vaginal tissue: A proof of concept study

As an effective anti-HIV drug, cabotegravir (CAB) is currently administered via oral and injection routes, leading to several drawbacks, such as poor oral bioavailability and problems in the injection application process, as well as low drug concentration in vaginal tissue of woman patients. To overcome these issues, for the first time, we formulated CAB into three types of vaginal gels, considering the benefits of vaginal tissue as a delivery route. Thermosensitive gel, mucoadhesive gel, and the combination of these gels were developed as suitable carriers for CAB. Pluronics®, hydroxy propyl methyl cellulose (HPMC), Carbomer and poly(ethylene glycol) (PEG) 400 were used as thermosensitive, mucoadhesive and permeation enhancer agents, respectively. The gels were evaluated for their thermosensitive and mucoadhesive properties, as well as their pH values, viscosities, gel erosions, drug content recovery, in vitro drug release, ex vivo permeation, ex vivo retention, hemolytic activities, Lactobacillus inhibition activities and in vivo irritation properties. The results showed that all formulations showed desired characteristics for vaginal administration. Importantly, all formulations did not show hemolytic activities and inhibitions to Lactobacillus as normal bacteria in the vagina. Furthermore, no irritation in the vaginal tissues of the rats was observed by histopathological studies. Considering the thermosensitive and mucoadhesive properties, the combination of Pluronic® F127, Pluronic F68, and HPMC in thermosensitive-mucoadhesive vaginal gels was selected as the optimum dosage form for CAB as this formulation was able to provide ease administration due to its liquid form at room temperature. The use of PEG in this formulation was able to increase the penetrability of CAB through vaginal tissue with 0.61 ± 0.05 mg and 17.28 ± 0.95 mg of CAB being able to penetrate and localize in the vagina, respectively. Essentially, the optimum formulation was retained in the vaginal mucosa for>8 h. To conclude, further extensive in vivo studies should now be conducted to evaluate the efficacy of this approach.

Manufacturing and Examination of Vaginal Drug Delivery System by FDM 3D Printing

Vaginal drug delivery systems can provide a long-term and constant liberation of the active pharmaceutical ingredient even for months. For our experiment, FDM 3D printing was used to manufacture the vaginal ring samples from thermoplastic polyurethane filament, which enables fast manufacturing of complex, personalized medications. 3D printing can be an excellent alternative instead of industrial manufacturing, which is complicated and time-consuming. In our work, the 3D printed vaginal rings were filled manually with jellified metronidazole or chloramphenicol for the treatment of bacterial vaginosis. The need for manual filling was certified by the thermogravimetric and heatflow assay results. The manufactured samples were analyzed by an Erweka USP type II Dissolution Apparatus, and the dissolution profile can be distinguished based on the applied jellifying agents and the API's. All samples were considered non-similar based on the pairwise comparison. The biocompatibility properties were determined by prolonged MTT assay on HeLa cells, and the polymer could be considered non-toxic. Based on the microbiological assay on E. coli metronidazole and chitosan containing samples had bactericidal effects while just metronidazole or just chitosan containing samples bacteriostatic effect. None of these samples showed a fungistatic or fungicide effect against C. albicans. Based on our results, we successfully manufactured 3D printed vaginal rings filled with jellified metronidazole.

Probiotic lactobacilli in formulas and hygiene products for the health of the urogenital tract

Lactobacilli are the predominant microorganisms of the healthy human vagina. A novel alternative for the prevention and treatment of female urogenital tract infections (UGTI) is the inclusion of these microorganisms as active pharmaceutical ingredients in probiotic formulas, and more recently in female hygienic products. Probiotics are defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.” A list of requirements must be considered during the development of probiotic product/formula for the female urogenital tract (UGT). This review aims to resume the requirements, probiotic characteristics, and clinical trial applied to determine the effect of probiotic and potentially probiotic strains on different woman’s physiological and pathological conditions, and in preterm birth prevention. A revision of female hygienic products available in the world market is included, together with novel studies applying nanotechnology for Lactobacillus incorporation in hygienic products. Further studies and well‐designed clinical trials are urgently required to complement the current knowledge and applications of probiotics in the female UGT. The use of probiotic formulas and products will improve and restore the ecological equilibrium of the UGT microbiome to prevent and treat UGTI in women under different conditions.

Recent advances in electrospun nanofiber vaginal formulations for women's sexual and reproductive health

Electrospinning is an innovative technique that allows production of nanofibers and microfibers by applying a high voltage to polymer solutions of melts. The properties of these fibers - which include high surface area, high drug loading capacity, and ability to be manufactured from mucoadhesive polymers - may be particularly useful in a myriad of drug delivery and tissue engineering applications. The last decade has witnessed a surge of interest in the application of electrospinning technology for the fabrication of vaginal drug delivery systems for the treatment and prevention of diseases associated with women's sexual and reproductive health, including sexually transmitted infections (e.g. infection with human immunodeficiency virus and herpes simplex virus) vaginitis, preterm birth, contraception, multipurpose prevention technology strategies, cervicovaginal cancer, and general maintenance of vaginal health. Due to their excellent mechanical properties, electrospun scaffolds are also being investigated as next-generation materials in the surgical treatment of pelvic organ prolapse. In this article, we review the latest advances in the field.

Synthesis and Characterization of Thiolated Gum Ghatti as a Novel Excipient: Development of Compression-Coated Mucoadhesive Tablets of Domperidone

Mucoadhesive polymers represent a major part of site-specific and localized retention strategies in oral drug delivery. The present research was designed to synthesize and characterize a novel mucoadhesive carbohydrate polymer (thiolated gum ghatti; TGG), which was employed to formulate mucoadhesive tablets of domperidone using an industrially viable compression coating technique. Thiolation of gum ghatti was achieved by the ester formation (esterification) between the hydroxyl group and the carboxyl group of gum ghatti and thioglycolic acid. TGG was characterized by various physicochemical techniques such as FTIR, XRD, SEM, and DSC. In rheological studies, the observed viscosities of pure gum mucin were 45.45 and 71.75 mPa·s and those of the thiolated gum were 78.7 and 112.58 mPa·s, respectively, in water and simulated gastric fluid. A significant increase in viscosity for thiolated gum may be attributed to increased macromolecular interactions responsible for enhanced mucoadhesive potential of thiolated gum. In silico studies corroborate the role of mucin gum interaction and energetic stabilization for enhanced mucoadhesion properties of thiolated gum. Ex vivo mucoadhesion strength of gum ghatti- and TGG-coated tablets was found to be ranging between 45.77 ± 1.49 and 88.16 ± 1.75 and 115.32 ± 2.36 and 184.65 ± 2.07 mN, respectively. In an acute oral toxicity study, TGG did not show any toxicity on the vital organs of the Wistar rat and proved to be a safe polymer. TGG may be regarded as a promising polymer for developing different mucoadhesive drug delivery systems.

Emulsion-Based Multicompartment Vaginal Drug Carriers: From Nanoemulsions to Nanoemulgels

In order to overcome the limitations associated with vaginal administration of drugs, e.g., the short contact time of the drug form with the mucosa or continuous carrier wash-out, the development of new carriers for gynecological use is necessary. Furthermore, high individual anatomical and physiological variability resulting in unsatisfactory therapeutic efficacy of lipophilic active substances requires application of multicompartment drug delivery systems. This manuscript provides an up-to-date comprehensive review of the literature on emulsion-based vaginal dosage forms (EVDF) including macroemulsions, microemulsions, nanoemulsions, multiple emulsions and self-emulsifying drug delivery systems. The first part of the paper discusses (i) the influence of anatomical-physiological conditions on therapeutic efficacy of drug forms after local and systemic administration, (ii) characterization of EVDF components and the manufacturing techniques of these dosage forms and (iii) methods used to evaluate the physicochemical and pharmaceutical properties of emulsion-based vaginal dosage forms. The second part of the paper presents (iv) the results of biological and in vivo studies as well as (v) clinical evaluation of EVDF safety and therapeutic efficacy across different indications.

Recent Advances in Polymer-Based Vaginal Drug Delivery Systems

The vagina has been considered a potential drug administration route for centuries. Most of the currently marketed and investigated vaginal formulations are composed with the use of natural or synthetic polymers having different functions in the product. The vaginal route is usually investigated as an administration site for topically acting active ingredients; however, the anatomical and physiological features of the vagina make it suitable also for drug systemic absorption. In this review, the most important natural and synthetic polymers used in vaginal products are summarized and described, with special attention paid to the properties important in terms of vaginal application. Moreover, the current knowledge on the commonly applied and innovative dosage forms designed for vaginal administration was presented. The aim of this work was to highlight the most recent research directions and indicate challenges related to vaginal drug administrations. As revealed in the literature overview, intravaginal products still gain enormous scientific attention, and novel polymers and formulations are still explored. However, there are research areas that require more extensive studies in order to provide the safety of novel vaginal products.

Development and characterization of chitosan nanoparticles loaded nanofiber hybrid system for vaginal controlled release of benzydamine

Vaginal infections caused by various pathogens such as fungi, viruses and protozoa are frequently seen. Systemic and local treatments can be applied to eliminate these infections. Novel vaginal drug delivery systems can be used to provide local treatment. Vaginal drug delivery systems prevent systemic side effects and can provide long-term drug release in the vaginal area. Nanofibers and nanoparticles have a wide range of applications and can also be preferred as vaginal drug delivery systems. Benzydamine is a non-steroidal anti-inflammatory and antiseptic drug which is used for treatment of vaginal infections. The aim of this study was to compare the nanofiber and gel formulations containing lyophilized benzydamine nanoparticles with nanofiber and gel formulations containing free benzydamine, and to provide prolonged release for protection from the vaginal infections. Ionic gelation method was used for the preparation of benzydamine loaded nanoparticles. To produce benzydamine nanoparticles loaded nanofiber formulations, polyvinylpyrrolidone (PVP) solutions were prepared at 10% concentrations and mixed with nanoparticles. Hydroxypropyl methylcellulose (HPMC) was used as a gelling agent at the concentration of 1% for the vaginal gel formulation. Nanoparticles were characterized in terms of zeta potential, polydispersity index and particle size. Viscosity, surface tension and conductivity values of the polymer solutions were measured for the electrospinning. Mechanical properties, contact angle and drug loading capacity of the fibers were determined. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), fourier-transform infrared (FT-IR) spectroscopy, mucoadhesion, ex vivo permeability studies and in vitro release studies were performed for the selected formulations. Ex vivo permeability studies were performed using Franz diffusion cell method. SEM and TEM images showed that fiber diameters increased with loading of nanoparticles. DSC studies showed no interaction between excipients used in the formulation. Tensile strength and elongation at break values of the fibers increased with the loading of nanoparticles, and the contact angle values of the fibers were found to be 0°. Addition of benzydamine nanoparticles to gel and nanofiber formulations increased mucoadhesion compared to free benzydamine loading formulations. Benzydamine nanoparticle loaded gel and nanofiber formulations penetrated slower than that of free benzydamine gel and fiber formulations. The results demonstrated that benzydamine and benzydamine nanoparticle loaded fibers and gels could be a potential drug delivery system for the treatment of vaginal infections. Chitosan nanoparticle loaded nanofiber formulations are offered as an alternative controlled release vaginal formulations for vaginal infections.

Gelatin and Glycerine-Based Bioadhesive Vaginal Hydrogel

AIM

The work's aim was the preparation and characterization of a hydrogel based on gelatin and glycerine, useful for site-specific release of benzydamine, an anti-inflammatory drug, able to attenuate the inflammatory process typical of the vaginal infection.

OBJECTIVE

The obtained hydrogel has been characterized by Electronic Scanning Microscopy (SEM) and Differential Scanning Calorimetry (DSC). In addition, due to the precursor properties, the hydrogel exhibits a relevant mucoadhesive activity.

METHODS

The swelling degree was evaluated at two different pHs and at defined time intervals. In particular, phosphate buffers were used at pH 6.6, in order to mimic the typical conditions of infectious diseases at the vaginal level, particularly for HIV-seropositive pregnant women, and pH 4.6, to simulate the physiological environment.

RESULTS

The obtained results revealed that the hydrogel swells up well at both pHs.

CONCLUSION

Release studies conducted at both pathological and physiological pHs have shown that benzydamine is released at the level of the vaginal mucosa in a slow and gradual manner. These data support the hypothesis of the hydrogel use for the site-specific release of benzydamine in the vaginal mucosa.

p-Coumaric acid loaded into liquid crystalline systems as a novel strategy to the treatment of vulvovaginal candidiasis

Vulvovaginal candidiasis (VVC) is an extremely common type of vaginal infection, which is mainly caused by Candida albicans. However, non-albicans Candida species are frequently more resistant to conventional antifungal agents and can represent up to 30% of cases. Due to side effects and increasing antifungal resistance presented by standard therapies, phenolic compounds, such as p-coumaric acid (p-CA), have been studied as molecules from natural sources with potential antifungal activity. p-CA is a poorly water-soluble compound, thus loading it into liquid crystals (LCs) may increase its solubility and effectiveness on the vaginal mucosa. Thereby, here we propose the development of mucoadhesive liquid crystalline systems with controlled release of p-CA, for the local treatment of VVC. Developed LCs consisted of fixed oily and aqueous phases (oleic acid and cholesterol (5:1) and poloxamer dispersion 16%, respectively), changing only the surfactant phase components (triethanolamine oleate (TEA-Oleate) or triethanolamine (TEA), the latter producing TEA-Oleate molecules when mixed with oleic acid). Systems were also diluted in artificial vaginal mucus (1:1 ratio) to mimic the vaginal environment and verify possible structural changes on formulations upon exposure to the mucosa. From the characterization assays, p-CA loaded TEA-Oleate systems presented mucoadhesive profile, liquid crystalline mesophases, well-organized structures and pseudoplastic behaviour, which are desirable parameters for topical formulations. Moreover, they were able to control the release of p-CA throughout the 12 h assay, as well as decrease its permeation into the vaginal mucosa. p-CA showed antifungal activity in vitro against reference strains of C. albicans (SC5314), C. glabrata (ATCC 2001) and C. krusei (ATCC 6258), and exhibited higher eradication of mature biofilms than amphotericin B and fluconazole. In vivo experiments demonstrated that the formulations reduced the presence of filamentous forms in the vaginal lavages and provided an improvement in swelling and redness present in the mice vaginal regions. Altogether, here we demonstrated the potential and feasibility of using p-CA loaded liquid crystalline systems as a mucoadhesive drug delivery system for topical treatment of VVC.

Mucoadhesive hyaluronic acid-based films for vaginal delivery of metronidazole

Bacterial vaginosis is a prevalent women's health issue that affects millions of women worldwide every year; however, current treatments are often messy, inconvenient, and ineffective. Therefore, we developed a new hyaluronic acid-based film to deliver metronidazole that would be more effective, more convenient, and at a pH similar to that of the normal vaginal environment. Films were made by crosslinking modified hyaluronic acid to create a hydrogel, in which metronidazole or metronidazole benzoate and methylcellulose were incorporated, and the hydrogel was dried to a thin film. Through release testing, coupled with assessments of handleability, tensile strength, and mucoadhesion, it was determined that the films have the potential to remain in the vaginal environment for an extended time period and gradually release the drug for at least 6 days, which is a typical treatment length. As such, the films present a viable alternative to current treatment methods, allowing for both easy handling and a single treatment while eliminating the issues of pH and overall inconvenience.

Chitosan-based systems aimed at local application for vaginal infections

Vaginal administration is a promising route for the local treatment of infectious vaginal diseases since it can bypass the first-pass metabolism, drug interactions, and adverse effects. However, the commercial products currently available for topical vulvovaginal treatment have low acceptability and do not adequately explore this route. Mucoadhesive systems can optimize the efficacy of drugs administered by this route to increase the retention time of the drug in the vaginal environment. Several polymers are used to develop mucoadhesive systems, among them chitosan, a natural polymer that is highly biocompatible and technologically versatile. Thus, the present review aimed to analyze the studies that used chitosan to develop mucoadhesive systems for the treatment of local vaginal infections. These studies demonstrated that chitosan as a component of mucoadhesive drug delivery systems (DDS) is a promising device for the treatment of vaginal infectious diseases, due to the intrinsic antimicrobial activity of this biopolymer and because it does not interfere with the effectiveness of the drugs used for the treatment.

Estradiol softgel inserts for the treatment of VVA symptoms: an expert opinion

INTRODUCTION

Vulvar and vaginal atrophy (VVA) affects up to two thirds of postmenopausal women, with symptoms of vaginal dryness, dyspareunia, and vulvar/vaginal irritation. Despite the availability of various treatments, women express dissatisfaction with their options. An estradiol (E2; 4-µg and 10-µg) softgel vaginal insert was approved by the Food and Drug Administration (FDA) to treat moderate to severe dyspareunia, a symptom of VVA, due to menopause. These inserts were designed to treat VVA effectively and safely while avoiding some of the drawbacks of other administration methods.

AREAS COVERED

This article reviews the physical characteristics and pharmacokinetic data of the E2 softgel vaginal insert. Primary and secondary efficacy endpoints and safety data are reviewed from the pivotal REJOICE trial (NCT02253173), and substudies that explore response rates, changes in vaginal epithelium by visual assessment, efficacy in patient subgroups, effects on sexual function, and patient satisfaction compared with other treatments.

EXPERT OPINION

The E2 insert shows that vaginal drug delivery is an optimal route of administration for locally treating VVA. This E2 softgel vaginal insert is a safe and effective treatment for symptoms of postmenopausal VVA. The E2 insert's pharmacokinetic characteristics are related to its unique formulation, rapid dissolution, and minimal systemic absorption.

ABBREVIATIONS

AE: adverse event; AUC: area under the concentration-time curve; BMI: body mass index; C_avg: average concentration; CI: confidence interval; C_max: maximum concentration; C_min: minimum concentration; E2: estradiol; FDA: Food and Drug Administration; FSFI: Female Sexual Function Index; GSM: genitourinary symptoms of menopause: MBS: most bothersome symptom; NAMS: North American Menopause Society; OR: odds ratio; PI: pulsatility index; PK: pharmacokinetic; REVIVE: Real Women's Views of treatment options for menopausal Vaginal changEs; RI: resistance index; ROC: receiver operating characteristic; TEAE: treatment-emergent adverse event; t_max: time to maximum concentration; VVA: vulvar and vaginal atrophy.

Formulating SLN and NLC as Innovative Drug Delivery Systems for Non-Invasive Routes of Drug Administration

Colloidal carriers diverge depending on their composition, ability to incorporate drugs and applicability, but the common feature is the small average particle size. Among the carriers with the potential nanostructured drug delivery application there are SLN and NLC. These nanostructured systems consist of complex lipids and highly purified mixtures of glycerides having varying particle size. Also, these systems have shown physical stability, protection capacity of unstable drugs, release control ability, excellent tolerability, possibility of vectorization, and no reported production problems related to large-scale. Several production procedures can be applied to achieve high association efficiency between the bioactive and the carrier, depending on the physicochemical properties of both, as well as on the production procedure applied. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes Lipid-based nanocarriers (LNCs) versatile delivery system for various routes of administration. The route of administration has a significant impact on the therapeutic outcome of a drug. Thus, the non-invasive routes, which were of minor importance as parts of drug delivery in the past, have assumed added importance drugs, proteins, peptides and biopharmaceuticals drug delivery and these include nasal, buccal, vaginal and transdermal routes. The objective of this paper is to present the state of the art concerning the application of the lipid nanocarriers designated for non-invasive routes of administration. In this manner, this review presents an innovative technological platform to develop nanostructured delivery systems with great versatility of application in non-invasive routes of administration and targeting drug release.

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.

Enhancement of Simvastatin ex vivo Permeation from Mucoadhesive Buccal Films Loaded with Dual Drug Release Carriers

BACKGROUND

Simvastatin (SMV), a hypocholesterolemic agent, suffers from very low bioavailability due to its poor aqueous solubility and extensive first-pass metabolism.

METHODS

Two SMV carrier systems, namely, polymeric drug inclusion complex (IC) and mixed micelles (MM) nanoparticles, were developed and loaded into mucoadhesive buccal films to enhance SMV bioavailability. The two carrier systems were characterized and their permeation across human oral epithelial cells (OEC) was studied. The effect of IC to MM ratio (X1) and the mucoadhesive polymer concentration (X2) on the cumulative percent of drug released, elongation percent and the mucoadhesive strength, from the prepared mucoadhesive films, were optimized. Ex vivo permeation across bovine mucosal tissue was investigated. The permeation parameters for the in vitro and ex vivo release data were calculated.

RESULTS

Complexation of SMV with hydroxypropyl beta-cyclodextrin (HP β-CD) was superior to all other polymers as revealed by the equilibrium saturation solubility, stability constant, complexation efficiency and thermodynamic potential. SMV-HP β-CD IC was utilized to develop a saturated polymeric drug solution. Both carrier systems showed enhanced permeation across OEC when compared to pure drug. X1 and X2 were significantly affecting the characteristics of the prepared films. The optimized mucoadhesive buccal film formulation loaded with SMV IC and drug MM nanoparticles demonstrated superior ex vivo permeation when compared to the corresponding pure drug buccal film, and the calculated permeation parameters confirmed this finding.

CONCLUSION

Mucoadhesive buccal films containing SMV IC and drug MM can be used to improve drug bioavailability; however, additional pharmacokinetic and pharmacodynamic studies are required.

Mucoadhesive Chitosan Delivery System with Chelidonii Herba Lyophilized Extract as a Promising Strategy for Vaginitis Treatment

Chelidonium majus (also known as celandine) contains pharmacologically active compounds such as isoquinoline alkaloids (e.g., chelidonine, sanguinarine), flavonoids, saponins, carotenoids, and organic acids. Due to the presence of isoquinoline alkaloids, Chelidonii herba extracts are widely used as an antibacterial, antifungal, antiviral (including HSV-1 and HIV-1), and anti-inflammatory agent in the treatment of various diseases, while chitosan is a biocompatible and biodegradable carrier with valuable properties for mucoadhesive formulations preparation. Our work aimed to prepare mucoadhesive vaginal drug delivery systems composed of Chelidonii herba lyophilized extract and chitosan as an effective way to treat vaginitis. The pharmacological safety of usage of isoquinoline alkaloids, based on MTT test, were evaluated for the maximum doses 36.34 ± 0.29 µg/mL and 0.89 ± 1.16 µg/mL for chelidonine and sanguinarine, respectively. Dissolution rate profiles and permeability through artificial membranes for chelidonine and sanguinarine after their introduction into the chitosan system were studied. The low permeability for used save doses of isoquinoline alkaloids and results of microbiological studies allow confirmation that system Chelidonii herba lyophilized extract chitosan 80/500 1:1 (w/w) is a promising strategy for vaginal use. Ex vivo studies of mucoadhesive properties and evaluation of tableting features demonstrated that the formulation containing Chelidonii herba lyophilized extract (120.0 mg) with chitosan (80/500—100.0 mg) and polymer content (HPMC—100.0 mg, microcrystalline cellulose—50.0 mg, lactose monohydrate—30.0 mg and magnesium stearate—4.0 mg) is a vaginal dosage form with prolonging dissolution profile and high mucoadhesion properties (up to 4 h).

The application of nanomaterial science in the formulation a novel antibiotic: Assessment of the antifungal properties of mucoadhesive clotrimazole loaded nanofiber versus vaginal films

Candidiasis is the origin of several chronic diseases and causes a wide range of symptoms from mucosal to systemic and deadly infections. Vaginal patches are one of the best drug delivery systems for the treatment of fungal infections in the vaginal environment, so a mucoadhesive film containing drugs such as clotrimazole and metronidazole is commercially available for patients. In the present study, a physicochemical comparison is made between clotrimazole loaded film and nanofiber fabricated with the new hybrid mucoadhesive formulation of dextran and alginate. Toxicity testing was performed using the MTT assay. Bioadhesion and antifungal effects were investigated for fibers and films. The release behavior of clotrimazole from two systems was evaluated by Franz cell in each case. The most important difference between nanofibrous and film mats were obtained in antifungal, mucoadhesive, Young's modulus and morphology. The nanofiber has a higher antifungal effect and two-fold adhesive to the mouse tissue, than film. The inherent flexibility of nanofiber obviated the need for a plasticizer, which may have cytotoxic side effects. The Clotrimazole loaded nanofibrous of Alginate/Dextran mats were successfully electrospun. They exhibited more bioadhesive with higher and faster antifungal properties versus similar formulation film. Further in vivo investigation is required for their application in vaginal candidiasis.

Natural polymers for vaginal mucoadhesive delivery of vinegar, using design of experiment methods

Background/Aim. Vinegars are of the main international traditional nutraceuticals which have been used as vaginal health protectant due to vagina pH balance maintenance and antimicrobial properties. Since the main used form of vinegar was liquid, it was difficult for vaginal application with low residence time; in this study a vaginal mucoadhesive gel of vinegar was designed. Methods. Xanthan gum (XG) and tragacanth (TG) were utilized as natural gel forming polymers. The effects of Xanthan gum and tragacanth on mucoadhesion strength and drug release of the gel formulations were optimized using a 3 level (32) factorial design. Several physico-chemical properties of the gel formulations including gel viscosity, spreadability, scanning electron microscopy (SEM) images of hydrogel chains, and release kinetic were also investigated. Results. demonstrated that tragacanth possesses a statistically significant effect on release rate control (p-value=0.0027) while both tragacanth and xanthan gum have significant effect (p value= 0.0001 and 0.0017, respectively) on mucoadhesion property. Conclusion. Design of experiment suggested that formulation F7 with 5% xanthan gum and 1% tragacanth (mucoadhesion = 0.4632 N and release rate = 88.8% in 6 hours) can be considered as the optimum formulation with some modifications.

Hydrogel Containing Oleoresin From Copaifera officinalis Presents Antibacterial Activity Against Streptococcus agalactiae

Streptococcus agalactiae or Group B Streptococcus (GBS) remains a leading cause of neonatal infections worldwide; and the maternal vaginal-rectal colonization increases the risk of vertical transmission of GBS to neonates and development of infections. This study reports the in vitro antibacterial effect of the oleoresin from Copaifera officinalis Jacq. L. in natura (copaiba oil) and loaded into carbomer-hydrogel against planktonic and sessile cells of GBS. First, the naturally extracted copaiba oil was tested for the ability to inhibit the growth and metabolic activity of planktonic and sessile GBS cells. The time-kill kinetics showed that copaiba oil exhibited a dose-dependent bactericidal activity against planktonic GBS strains, including those resistant to erythromycin and/or clindamycin [minimal bactericidal concentration (MBC) ranged from 0.06 mg/mL to 0.12 mg/mL]. Copaiba oil did not inhibit the growth of different Lactobacillus species, the indigenous members of the human microbiota. The mass spectral analyses of copaiba oil showed the presence of diterpenes, and the kaurenoic acid appears to be one of the active components of oleoresin from C. officinalis related to antibacterial activity against GBS. Microscopy analyses of planktonic GBS cells treated with copaiba oil revealed morphological and ultrastructural alterations, displaying disruption of the cell wall, damaged cell membrane, decreased electron density of the cytoplasm, presence of intracellular condensed material, and asymmetric septa. Copaiba oil also exhibited antibacterial activity against established biofilms of GBS strains, inhibiting the viability of sessile cells. Low-cost and eco-friendly carbomer-based hydrogels containing copaiba oil (0.5% – CARB-CO 0.5; 1.0% – CARB-CO 1.0) were then developed. However, only CARB-CO 1.0 preserved the antibacterial activity of copaiba oil against GBS strains. This formulation was homogeneous, soft, exhibited a viscoelastic behavior, and showed good biocompatibility with murine vaginal mucosa. Moreover, CARB-CO 1.0 showed a slow and sustained release of the copaiba oil, killing the planktonic and sessile (established biofilm) cells and inhibiting the biofilm formation of GBS on pre-coated abiotic surface. These results indicate that carbomer-based hydrogels may be useful as topical systems for delivery of copaiba oil directly into de vaginal mucosa and controlling S. agalactiae colonization and infection.

A Paclitaxel-Based Mucoadhesive Nanogel with Multivalent Interactions for Cervical Cancer Therapy

Cervical cancer treatment is subject to limited drug access to locally diseased targets and generally resistant to chemotherapy, thus it is essential to develop a local drug delivery system to overcome these problems, premised on guaranteeing drug efficacy. With this goal in mind, a multivalent interactions-based mucoadhesive nanogel for vaginal delivery is proposed. Briefly, the nanogel is constructed with mucoadhesive poly(acrylic acid) as the backbone and multiple inclusions between β-cyclodextrin and paclitaxel as the crosslinking points. The in vitro experiments demonstrate that nanogel exerts high cytotoxicity to cancer cells, reverses multidrug resistance effectively, and successfully promotes the permeation of drugs. More to the point, as proved in the in vivo experiments, the retention time in the vagina is prolonged and the tumor growth is effectively suppressed by the nanogel without any side effects in the orthotopic cervical cancer model. As mentioned above, this novel mucoadhesive nanogel is believed to be a useful tool toward designing drug delivery systems for cervical cancer treatment.

Maleimide-functionalised PLGA-PEG nanoparticles as mucoadhesive carriers for intravesical drug delivery

Low permeability of the urinary bladder epithelium, poor retention of the chemotherapeutic agents due to dilution and periodic urine voiding as well as intermittent catheterisations are the major limitations of intravesical drug delivery used in the treatment of bladder cancer. In this work, maleimide-functionalised poly(lactide-co-glycolide)-block-poly(ethylene glycol) (PLGA-PEG-Mal) nanoparticles were developed. Their physicochemical characteristics, including morphology, architecture and molecular parameters have been investigated by means of dynamic light scattering, transmission electron microscopy and small-angle neutron scattering techniques. It was established that the size of nanoparticles was dependent on the solvent used in their preparation and molecular weight of PEG, for example, 105 ± 1 nm and 68 ± 1 nm particles were formed from PLGA_20K-PEG_5K in dimethyl sulfoxide and acetone, respectively. PLGA-PEG-Mal nanoparticles were explored as mucoadhesive formulations for drug delivery to the urinary bladder. The retention of fluorescein-loaded nanoparticles on freshly excised lamb bladder mucosa in vitro was evaluated and assessed using a flow-through fluorescence technique and Wash Out₅₀ (WO₅₀) quantitative method. PLGA-PEG-Mal nanoparticles (NPs) exhibited greater retention on urinary bladder mucosa (WO₅₀ = 15 mL) compared to maleimide-free NPs (WO₅₀ = 5 mL). The assessment of the biocompatibility of PEG-Mal using the slug mucosal irritation test revealed that these materials are non-irritant to mucosal surfaces.

Mucoadhesive In Situ Gelling Liquid Crystalline Precursor System to Improve the Vaginal Administration of Drugs

The vaginal mucosa is a very promising route for drug administration due to its high permeability and the possibility to bypass first pass metabolism; however, current vaginal dosage forms present low retention times due to their dilution in vaginal fluids, which hampers the efficacy of many pharmacological treatments. In order to overcome these problems, this study proposes to develop a mucoadhesive in situ gelling liquid crystalline precursor system composed of 30% of oleic acid and cholesterol (7:1), 40% of ethoxylated and propoxylated cetyl alcohol, and 30% of a dispersion of 16% Poloxamer 407. The effect of the dilution with simulated vaginal fluid (SVF) on this system was evaluated by polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), rheological studies, texture profile analysis (TPA), mucoadhesion study, in vitro drug release test using hypericin (HYP) as drug model, and cytotoxicity assay. PLM and SAXS confirmed the formation of an isotropic system. After the addition of three different concentrations of SVF (30, 50, and 100%), the resultant formulations presented anisotropy and characteristics of viscous lamellar phases. Rheology shows that formulations with SVF behaved as a non-Newtonian fluid with suitable shear thinning for vaginal application. TPA and mucoadhesion assays indicated the formation of long-range ordered systems as the amount of SVF increases which may assist in the fixation of the formulation on the vaginal mucosa. The formulations were able to control about 75% of the released HYP demonstrating a sustained release profile. Finally, all formulations acted as safe vaginal drug delivery systems.

Modifications in Vaginal Microbiota and Their Influence on Drug Release: Challenges and Opportunities

Vaginal drug delivery represents an attractive alternative to achieve local and systemic effects due to the high contact surface exposed, the mucoadhesion of the epithelium, and the high innervation that facilitates the absorption of drugs into the bloodstream. However, despite the confinement of the vaginal cavity, it is an organ with a highly variable microenvironment. Mechanical alterations such as coitus, or chemical changes such as pH and viscosity, modify the release of drugs. In addition, changes in vaginal microbiota can influence the entire vaginal microenvironment, thus determining the disposition of drugs in the vaginal cavity and decreasing their therapeutic efficacy. Therefore, the influence of microorganisms on vaginal homeostasis can change the pre-established scenario for the application of drugs. This review aims to provide an explanation of normal vaginal microbiota, the factors that modify it, its involvement in the administration of drugs, and new proposals for the design of novel pharmaceutical dosage forms. Finally, challenges and opportunities directed toward the conception of new effective formulations are discussed.

Formulation, stability study and preclinical evaluation of a vaginal cream containing curcumin in a rat model of vulvovaginal candidiasis

Owing to the growing resistance among isolates of Candida species to usual antifungal agents and the well-known therapeutic potential of curcumin, the purpose of this study was to develop and validate a vaginal formulation containing this substance and to evaluating its effectiveness in the treatment of experimental vulvovaginal candidiasis. Curcumin was incorporated in a vaginal cream in three concentrations (0.01%, 0.1% and 1.0%). The different concentrations of the cream and its controls were intravaginally administered in an immunosuppressed rat model to evaluate the efficacy in the treatment of experimental vulvovaginal candidiasis. Samples of the cream were also subjected to centrifugation and physical stability tests and an analytical method for quantification of curcumin was validated based on HPLC. The formulation was stable and the HPLC method could be considered suitable for the quantitative determination of curcumin in the cream. After 6 days of preclinical study, the number of infected animals was 1/6 in all groups treated with curcumin vaginal cream and the fungal burden showed a progressive reduction. Reduction in the inflammatory infiltrate was observed in the group treated with 1.0% cream. Vaginal cream containing curcumin could be considered a promising effective antifungal medicine in the treatment of vulvovaginal candidiasis.

Clinical translation of microbe-based therapies: Current clinical landscape and preclinical outlook

Next generation microbe-based therapeutics, inspired by the success of fecal microbiota transplants, are being actively investigated in clinical trials to displace or eliminate pathogenic microbes to treat various diseases in the gastrointestinal tract, skin, and vagina. Genetically engineered microbes are also being investigated in the clinic as drug producing factories for biologic delivery, which can provide a constant local source of drugs. In either case, microbe-therapeutics have the opportunity to address unmet clinical needs and open new areas of research by reducing clinical side effects associated with current treatment modalities or by facilitating the delivery of biologics. This review will discuss examples of past and current clinical trials that are investigating microbe-therapeutics, both microbiome-modulating and drug-producing, for the treatment of a range of diseases. We then offer a perspective on how preclinical approaches, both those focused on developing advanced delivery systems and those that use in vitro microbiome model systems to inform formulation design, will lead to the realization of next-generation microbe-therapeutics.

Nanolipid Gel of an Antimycotic Drug for Treating Vulvovaginal Candidiasis-Development and Evaluation

This paper focuses on the development and evaluation of mucoadhesive vaginal gel of fluconazole using nanolipid carriers to enhance tissue deposition in treating vulvovaginal candidiasis. Treatment of vulvovaginal candidiasis includes antimycotic agents prescribed for 1 to 7 days or longer, in relapse either orally or topically. The delivery of fluconazole as nanolipid carriers in vaginal gel can be proposed as suitable alternative to the existing conventional formulations to improve the patient acceptability, compliance and localized drug action. The nanolipid carriers of fluconazole were prepared by phase inversion temperature technique and incorporated into Carbopol 974P as gelling polymer. GRAS excipients selected and optimized were Precirol ATO 5, oleic acid and Kolliphor RH 40 to produce nanolipid dispersions. Stable nanolipid dispersions were developed using sodium dodecyl sulfate as the charge inducer. The optimized nanolipid dispersion of fluconazole had particle size, polydispersity index and zeta potential value of 158.33 ± 2.55 nm, 0.278 ± 0.003 and - 27.33 ± 0.40 mV, respectively and the average entrapment of fluconazole in the lipid carriers was found to be 67.24 ± 0.87%. The optimized vaginal gel had satisfactory mucoadhesive strength and rheological properties to facilitate vaginal application. The fluconazole release from the gel was sustained showing 30.69 ± 1.02% drug deposition in the porcine vaginal mucosa at the end of 8 h with improved antifungal activity against Candida albicans during well diffusion studies. The optimized gel was non-irritant to the vaginal mucosa of female Wistar rats with no signs of erythema or edema.