Spray-dried powders improve the controlled release of antifungal tioconazole-loaded polymeric nanocapsules compared to with lyophilized products

Antifungal activity against Candida albicans of methyl 3,5-dinitrobenzoate loaded nanoemulsion

The objective of this study was to evaluate the antifungal activity of free methyl 3,5 dinitrobenzoate (MDNB) and its nanoemulsion (MDNB-NE) against strains of Candida albicans. Additionally, a molecular modeling study was also carried out to propose the mechanism of action and toxicity of MDNB. These results demonstrated the MDNB-NE presented a droplet size of 181.16 ± 3.20 nm and polydispersity index of 0.30 ± 0.03. MDNB and MDNB-NE inhibited the growth of all strains with minimum inhibitory concentrations of 0.27-1.10 mM. The biological results corroborated the molecular model, which pointed to a multi-target antifungal mechanism of action for MDNB in C. albicans. The study could serve as a basis for further research involving compounds with nitro groups with antifungal.

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.

Tioconazole-Loaded Transethosomal Gel Using Box-Behnken Design for Topical Applications: In Vitro, In Vivo, and Molecular Docking Approaches

Tioconazole (TCZ) is a broad-spectrum fungicidal BCS class II drug with reported activity against Candida albicans, dermatophytes, and certain Staphylococci bacteria. We report the use of TCZ-loaded transethosomes (TEs) to overcome the skin's barrier function. TCZ-loaded TEs were fabricated by using a cold method with slight modification. Box-Behnken composite design was utilized to investigate the effect of independent variables. The fabricated TEs were assessed with various physicochemical characterizations. The optimized formulation of TCZ-loaded TEs was incorporated into gel and evaluated for pH, conductivity, drug content, spreadability, rheology, in vitro permeation, ex vivo permeation, and in vitro and in vivo antifungal activity. The fabricated TCZ-loaded TEs had a % EE of 60.56 to 86.13, with particle sizes ranging from 219.1 to 757.1 nm. The SEM images showed spherically shaped vesicles. The % drug permeation was between 77.01 and 92.03. The kinetic analysis of all release profiles followed Higuchi's diffusion model. The FTIR, DSC, and XRD analysis showed no significant chemical interactions between the drug and excipients. A significantly higher antifungal activity was observed for TCZ-loaded transethosomal gel in comparison to the control. The in vivo antifungal study on albino rats indicated that TCZ-loaded transethosomal gel showed a comparable therapeutic effect in comparison to the market brand Canesten®. Molecular docking demonstrated that the TCZ in the TE composition was surrounded by hydrophobic excipients with increased overall hydrophobicity and better permeation. Therefore, TCZ in the form of transethosomal gel can serve as an effective drug delivery system, having the ability to penetrate the skin and overcome the stratum corneum barrier with improved efficacy.

Photocatalytic degradation of Rhodamine B dye by nanostructured powder systems containing nanoencapsulated curcumin or ascorbic acid and ascorbyl palmitate liposomal

Due to inadequate treatment and incorrect management, wastewater with dyes has a great toxic potential as an environmental liability, representing a major concern. In this context, this work aims to investigate the potential application of nanostructured powdery systems (nanocapsules and liposomes) in the photodegradation of Rhodamine B (RhB) dye, under UV and visible irradiation. Curcumin nanocapsules and liposomes containing ascorbic acid and ascorbyl palmitate were prepared, characterized, and dried using the spray drying technique. The drying processes of the nanocapsule and the liposome showed yields of 88% and 62%, respectively, and, after aqueous resuspension of the dry powders, it was possible to recover the nanocapsule size (140 nm) and liposome size (160 nm). The dry powders were characterized by Fourier transform infrared spectroscopy (FTIR), N₂ physisorption at 77 K, X-ray diffraction (XRD), and diffuse reflectance spectroscopy (DRS-UV). Under UV irradiation, 64.8% and 58.48% of RhB were removed with nanocapsules and liposomes, respectively. While under visible radiation, nanocapsules and liposomes were able to degrade 59.54% and 48.79% of RhB, respectively. Under the same conditions, commercial TiO₂ showed degradation of 50.02% (UV) and 42.14% (visible). After 5 cycles of reuse, there was a decrease of about 5% for dry powders under UV irradiation and 7.5% under visible irradiation. Therefore, the nanostructured systems developed have potential application in heterogeneous photocatalysis for the degradation of organic pollutants, such as RhB, as they demonstrated superior photocatalytic performance to commercial catalysts (nanoencapsulated curcumin > ascorbic acid and ascorbyl palmitate liposomal > TiO₂).

Characterization of the hydrochloride salt hemihydrate as a new salt of the antifungal agent tioconazole

Tioconazole is an effective antifungal agent, which has a very low solubility in aqueous media, that limits its bioavailability and efficacy. In an effort to overcome the drug limitations by improving its solubility, the hydrochloride salt was prepared in methanolic 1M HCl and obtained as the hemihydrate, as demonstrated by elemental analysis. Single crystals were grown by slow evaporation from an aqueous 1M HCl solution and their structure was determined using single-crystal X-ray diffraction at 302 K. The structures resulting from dehydration and further rehydration were also assessed, at 333 and 283 K, respectively. The morphology of the crystal, which exhibited birefringence under polarized light, was verified by hot stage microscopy. The solid was characterized by additional means, including thermal analysis (melting point, differential scanning calorimetry and thermogravimetry), spectroscopic methods (mid infrared, near infrared, ¹H, ¹³C and ¹⁵N nuclear magnetic resonance in solution, as well as ¹³C and ¹⁵N solid state with spinning at the magic angle) and X-ray diffraction techniques. Functional evaluation tests, including the intrinsic dissolution rate and the dissolution of powders were also performed. In the intrinsic dissolution rate test, the salt proved to dissolve over 2000 times faster than tioconazole. The results suggest that the new salt has physicochemical and performance properties which may support its use as a replacement of the free base in certain applications, especially where improved dissolution rate, solubility or bioavailability of the drug would be desired.

Trypanosoma cruzi: Does the intake of nanoencapsulated benznidazole control acute infections?

Chagas Disease (CD) affects around eight million people worldwide. It is considered a neglected disease that presents few treatment options with efficacy only in the acute phase. Nanoparticles have many positive qualities for treating parasite infections and may be effectively and widely employed in clinical medicine. This research aimed to evaluate the nanoencapsulated benznidazole treatment in animals experimentally infected with Trypanosoma cruzi. To analyze the treatment efficacy, we evaluated survival during thirty days, parasitemia, genotoxicity, and heart and liver histopathology. Thirty-five female Swiss mice were organized into seven groups characterizing a dose curve: A - Negative control (uninfected animals), B - Positive control (infected animals), C - Benznidazole (BNZ) 100 mg/kg (infected animals), D - 5 mg/kg Benznidazole nanocapsules (NBNZ) (infected animals), E - 10 mg/kg Benznidazole nanocapsules (infected animals), F - 15 mg/kg Benznidazole nanocapsules (infected animals), G - 20 mg/kg Benznidazole nanocapsules (infected animals). The animals were infected with the Y strain of T. cruzi intraperitoneally. The treatment was administered for eight days by oral gavage. It was possible to observe that the treatment with the highest NBNZ dose presented efficacy similar to the standard benznidazole drug. The 20 mg/kg NBNZ dose was able to reduce parasitemia, increase survival, and drastically reduce heart and liver tissue damage compared to the 100 mg/kg BNZ dose. Moreover, it showed a lower DNA damage index than the BNZ treatment. In conclusion, the nanoencapsulation of BNZ promotes an improvement in parasite proliferation control with a five times smaller dose relative to the standard dose of free BNZ, thus demonstrating to be a potential innovative therapy for CD.

Production of nanostructured systems: Main and innovative techniques

In the constant search for the development of more-specific and more-selective drugs, especially with regard to the challenge of encapsulating hydrophilic molecules, polymer nanotechnologies are remarkable for their biocompatible and biodegradable properties. The most-used nanoencapsulation methods consist of emulsification procedures, where emulsified droplets of a given polymer and drug solidify into nanoparticles after solvent extraction from the polymeric phase. This review introduces conventional emulsification methods but also highlights new emulsification technologies such as microfluidics, membrane emulsification and other techniques, including spray drying, inkjet printing and electrospraying.

Progress of polymer-based strategies in fungal disease management: Designed for different roles

Fungal diseases have posed a great challenge to global health, but have fewer solutions compared to bacterial and viral infections. Development and application of new treatment modalities for fungi are limited by their inherent essential properties as eukaryotes. The microorganism identification and drug sensitivity analyze are limited by their proliferation rates. Moreover, there are currently no vaccines for prevention. Polymer science and related interdisciplinary technologies have revolutionized the field of fungal disease management. To date, numerous advanced polymer-based systems have been developed for management of fungal diseases, including prevention, diagnosis, treatment and monitoring. In this review, we provide an overview of current needs and advances in polymer-based strategies against fungal diseases. We high light various treatment modalities. Delivery systems of antifungal drugs, systems based on polymers' innate antifungal activities, and photodynamic therapies each follow their own mechanisms and unique design clues. We also discuss various prevention strategies including immunization and antifungal medical devices, and further describe point-of-care testing platforms as futuristic diagnostic and monitoring tools. The broad application of polymer-based strategies for both public and personal health management is prospected and integrated systems have become a promising direction. However, there is a gap between experimental studies and clinical translation. In future, well-designed in vivo trials should be conducted to reveal the underlying mechanisms and explore the efficacy as well as biosafety of polymer-based products.

Bio-films based on alginate/modified clay through spray drying: Mechanical, rheological, morphological, and transport properties for potential use as active food packaging

In this study, encapsulated modified montmorillonite with alginate (MMT-TBZC16/Alg) content and its incorporation into the biopolymer on morphological, mechanical, rheological, and transport properties of bio-based films based on chitosan were analyzed. The spray-drying approach was used to create organo-modified montmorillonite with alginate as a biopolymer. These encapsulating materials were then described and used as reinforcing agents for chitosan in the second step of this investigation to produce new reinforced biofilms with improved performance. This study aimed to study the effect of the addition of encapsulated organo-montmorillonite into the chitosan solution on the mechanical, rheological, and transport properties of the elaborated films. Films reinforced with encapsulated modified montmorillonite were characterized using Fourier transform infrared spectroscopy (FTIR), Water vapor transmission rate (WVTR) as well as mechanical and rheological properties. Adding encapsulated reinforcing agents to chitosan-based films is an option for improving mechanical and water barrier qualities. These results suggest that the developed MMT-TBZC16/Alginate-based chitosan films with higher performances could be used in designing potential packaging films.

Enhancement of the functionality of women with knee osteoarthritis by a gel formulation with Caryocar coriaceum Wittm ("Pequi") nanoencapsulated pulp fixed oil

Osteoarthritis (OA) is a degenerative joint disease that occurs when there is a change in the mechanical and biological properties of the articular cartilage and the subchondral bone; The condition is more prevalent in women than in men. Pequi oil (PO), which is extracted from the fruits of the pequi tree (Caryocar coriaceum Wittm), is widely used in traditional medicine in the Brazilian northeast for the management of inflammation and joint pain. The aim of this study was to develop a pharmaceutical formulation containing Carbopol® hydrogel nanoencapsulated with pequi pulp fixed oil (PeONC) and evaluate its therapeutic effect on functionality and pain in women with knee osteoarthritis. The study was divided into two stages: Stage 1 - preparation and physico-chemical characterization of the pharmaceutical formulation containing PeONC, cell viability assays and skin irritability testing. Step 2 - A double-blind randomized clinical trial evaluating knee symptoms, quality of life, pressure pain, function, muscle strength and range of motion. The nanoformulation was in a gel form, with a particle size of 209.5 ± 1.06 nm, a pH of 6.23 ± 0.45, a zeta potential of - 23.1 ± 0.4 mV, a polydispersity index of 0.137 ± 0.52, and containing nanocapsules with a spherical shape a polymeric wall and an oily nucleus. The gel showed no cytotoxicity and was not irritating to human skin. The treatment with PeONC increased the strength of the knee flexor and extensor muscles and the total motion range of the knee. In addition, the treatment reduced knee instability, pain, swelling, and locking; There was also an improvement in some items of the SF-36 quality of life questionnaire such as in respect of functional capacity and social aspects. In conclusion, PeONC was found to be a stable, safe formulation with no toxicity in respect of topical use in humans. Additionally, the treatment produced an increase in muscle strength and functionality that was associated with reduced knee symptoms and improved quality of life. Our findings showed that in a group of women treated with PeONC mitigated the symptoms of knee osteoarthritis.

Stabilization by Nano Spray Dryer of Pioglitazone Polymeric Nanosystems: Development, In Vivo, Ex Vivo and Synchrotron Analysis

Pioglitazone-loaded PLGA-PEG nanoparticles (NPs) were stabilized by the spray drying technique as an alternative to the treatment of ocular inflammatory disorders. Pioglitazone-NPs were developed and characterized physiochemically. Interaction studies, biopharmaceutical behavior, ex vivo corneal and scleral permeation, and in vivo bioavailability evaluations were conducted. Fibrillar diameter and interfibrillar corneal spacing of collagen was analyzed by synchrotron X-ray scattering techniques and stability studies at 4 °C and was carried out before and after the spray drying process. NPs showed physicochemical characteristics suitable for ocular administration. The release was sustained up to 46 h after drying; ex vivo corneal and scleral permeation profiles of pioglitazone-NPs before and after drying demonstrated higher retention and permeation through cornea than sclera. These results were correlated with an in vivo bioavailability study. Small-angle X-ray scattering (SAXS) analysis did not show a significant difference in the organization of the corneal collagen after the treatment with pioglitazone-NPs before and after the drying process, regarding the negative control. The stabilization process by Nano Spray Dryer B-90 was shown to be useful in preserving the activity of pioglitazone inside the NPs, maintaining their physicochemical characteristics, in vivo bioavailability, and non-damage to corneal collagen function after SAXS analysis was observed.

Lyophilization of Nanocapsules: Instability Sources, Formulation and Process Parameters

Polymeric nanocapsules have gained more and more interest in the medical sciences. Their core-shell structure offers numerous advantages, especially regarding their use as drug delivery systems. This review begins by presenting the different intrinsic sources of the instability of nanocapsules. The physical and chemical potential instabilities of nanocapsules reduce their shelf-life and constitute a barrier to their clinical use and to their commercialization. To overcome these issues, lyophilization is often used as a process of choice in the pharmaceutical industry especially when labile compounds are used. The state of the art of lyophilization nanocapsules is reviewed. The formulation properties and the process parameters are discussed for a complete understanding of their impact on the stability and storage of the final dried product. To assess the quality of the dried product, various characterization methods are also discussed.

Microparticle encapsulation of a tuberculosis subunit vaccine candidate containing a nanoemulsion adjuvant via spray drying

Spray drying is a technique that can be used to stabilize biopharmaceuticals, such as vaccines, within dry particles. Compared to liquid pharmaceutical products, dry powder has the potential to reduce costs associated with refrigerated storage and transportation. In this study, spray drying was investigated for processing an adjuvanted tuberculosis subunit vaccine, formulated as an oil-in-water nanoemulsion, into a dry powder composed of microparticles. Applying in-silico approaches to the development of formulation and processing conditions, successful encapsulation of the adjuvanted vaccine within amorphous microparticles was achieved in only one iteration, with high retention (>90%) of both the antigen and adjuvant system. Moisture-controlled stability studies on the powder were conducted over 26 months at temperatures up to 40 °C. Results showed that the powder was physically stable after 26 months of storage for all tested temperatures. Adjuvant system integrity was maintained at temperatures up to 25 °C after 26 months and after one month of storage at 40 °C. The spray-dried product demonstrated improved antigen thermostability when stored above refrigerated temperatures as compared to the liquid product. These results demonstrate the feasibility of spray drying as a method of encapsulating and stabilizing an adjuvanted vaccine.

(-)-linalool-Loaded Polymeric Nanocapsules Are a Potential Candidate to Fibromyalgia Treatment

Fibromyalgia (FM) is a chronic disease that has as main characteristic generalized musculoskeletal pain, which can cause physical and emotional problems to patients. However, pharmacological therapies show side effects that hamper the adhesion to treatment. Given this, (-)-linalool (LIN), a monoterpene with several therapeutic properties already reported in scientific literature as anti-depressive, antinociceptive, anti-inflammatory, and antihyperalgesic also demonstrated therapeutic potential in the treatment of FM. Nevertheless, physicochemical limitations as high volatilization and poor water-solubility make its use difficult. In this perspective, this present research had performed the incorporation of LIN into polymeric nanocapsules (LIN-NC). Size, morphology, encapsulation efficiency, cytotoxicity, and drug release were performed. The antihyperalgesic effect of LIN-NC was evaluated by a chronic non-inflammatory muscle pain model. The results demonstrated that the polymeric nanocapsules showed particle size of 199.1 ± 0.7 nm with a PDI measurement of 0.13 ± 0.01. The drug content and encapsulation efficiency were 13.78 ± 0.05 mg/mL and 80.98 ± 0.003%, respectively. The formulation did not show cytotoxicity on J774 macrophages. The oral treatment with LIN-NC and free-LIN increased the mechanical withdrawal threshold on all days of treatment in comparison with the control group. In conclusion, LIN-NC is a promising proposal in the development of phytotherapy-based nanoformulations for future clinical applications.

Phenytoin-loaded lipid-core nanocapsules improve the technological properties and in vivo performance of fluidised bed granules

Lipid-core nanocapsules (LNCs) were recently reported by our group as a suitable binder system to produce fluidised bed granules. However, there is still a lack of knowledge about the influence of using these nanocarriers loaded with a drug on the properties of the granules and their in vivo performance. Therefore, this study was designed to produce innovative fluidised bed granules containing phenytoin-loaded LNCs (LNC_PHT) as a strategy to evaluate the influence of the presence of the drug-loaded nanocarriers on their in vitro and in vivo properties. Granules were produced using a mixture of maltodextrin and phenytoin (1:0.004 w/w) as substrate. They were prepared by fluid bed granulation using water or LNC_PHT as the liquid binder, affording good yields (73-82%) of granules with low moisture content (<5%). Granules prepared with LNC_PHT had larger mean size (122 μm) compared to maltodextrin primary particles (50 μm) due to the formation of solid bridges. Moreover, the use of LNC_PHT as the liquid binder improved their powder flow properties. The nanocarriers were recovered after aqueous dispersion (3.00 mg.mL^-1 of PHT) with a redispersibility close to 90%. After reconstitution in water, granules containing LNC_PHT showed an improved dissolution behaviour compared to those prepared without them. In addition, they showed a higher mucoadhesive effect due to a combined effect of the LNC_PHT and maltodextrin in the interactions with porcine intestinal mucosa. Regarding the in vivo studies, granules containing the combination of non-encapsulated PHT and PHT-loaded lipid-core nanocapsules increased the latency to seizures compared to placebo granules, showing effective anticonvulsant effect in mice. In conclusion, the use of drug-loaded nanocapsules as binder is an encouraging approach to produce fluidised bed mucoadhesive granules with improved technological properties and in vivo performance.

Design and Characterization of Chitosan Nanoformulations for the Delivery of Antifungal Agents

Among different Candida species triggering vaginal candidiasis, Candida albicans is the most predominant yeast. It is commonly treated using azole drugs such as Tioconazole (TIO) and Econazole (ECO). However, their low water solubility may affect their therapeutic efficiency. Therefore, the aim of this research was to produce a novel chitosan nanocapsule based delivery system comprising of TIO or ECO and to study their suitability in vaginal application. These systems were characterized by their physicochemical properties, encapsulation efficiency, in vitro release, storage stability, cytotoxicity, and in vitro biological activity. Both nanocapsules loaded with TIO (average hydrodynamic size of 146.8 ± 0.8 nm, zeta potential of +24.7 ± 1.1 mV) or ECO (average hydrodynamic size of 127.1 ± 1.5 nm, zeta potential of +33.0 ± 1.0 mV) showed excellent association efficiency (99% for TIO and 87% for ECO). The analysis of size, polydispersity index, and zeta potential of the systems at 4, 25, and 37 °C (over a period of two months) showed the stability of the systems. Finally, the developed nanosystems presented fungicidal activity against C. albicans at non-toxic concentrations (studied on model human skin cells). The results obtained from this study are the first step in the development of a pharmaceutical dosage form suitable for the treatment of vaginal candidiasis.

Green synthesis of silver nanoparticles using Zingiber officinale and Thymus vulgaris extracts: characterisation, cell cytotoxicity, and its antifungal activity against Candida albicans in comparison to fluconazole

Fluconazole (FLZ) application as a highly successful commercial antifungal azole agent to treat the fungal infections is limited due to emergence of FLZ-resistant candida. In this study, the potential of green synthesised silver nanoparticles (NPs) as an antifungal agent against Candida albicans fungal pathogen is investigated. The extract of ginger (Zingiber officinale) and thyme (Thymus vulgaris) plays as reducing agent, capping agent and antifungal agent. The UV-visible spectroscopy shows the peak of surface plasmon resonance of synthesised Ag NPs after a period of time. The synthesised Ag NPs are spherical, with average sizes of 12 and 18 nm based on ginger and thyme extract, respectively. Fourier transform infrared spectroscopy confirms the adsorption of the plant extract on the surface of the as-prepared Ag NPs. Based on the minimum inhibitory concentration (MIC) method against Candida albicans, the antifungal activity of as-prepared green synthesised Ag NPs shows higher inhibitory in comparison to FLZ. Finally, the Ag NPs synthesised via thyme extract shows no cytotoxicity with concentration below 3.5 ppm, which can be considered as an appropriate candidate instead of FLZ to treat the superficial fungal infections.

New approaches to identification and characterization of tioconazole in raw material and in pharmaceutical dosage forms

Tioconazole (TCZ), a broad-spectrum antifungal agent, has significant activity against Candida albicans and other Candida species, and therefore, it is indicated for the topical treatment of superficial mycoses. The main goal of this work is to report an exhaustive identification and characterization procedure to improve and facilitate the online quality control and continuous process monitoring of TCZ in bulk material and loaded in two different dosage forms: ovules and nail lacquer. The methodologies were based on thermal (differential scanning calorimetry (DSC), melting point, and thermogravimetry (TG)), spectroscopic (ultraviolet (UV), Raman, near infrared (NIR), infrared spectroscopy coupled to attenuated total reflectance (FTIR-ATR), and nuclear magnetic resonance (NMR)), microscopic and X-ray diffraction (XRD). The TCZ bulk powder showed a high crystallinity, as observed by XRD, with a particles size distribution (3-95 µm) resolved by microscopic measurements. TCZ melting point (82.8 °C) and a degradation peak centered at 297.8 °C were obtained by DSC and DTG, respectively. An unambiguous structure elucidation of TCZ was obtained by mono- and two- dimensional 1H and 13C NMR spectral data analysis. The FTIR-ATR, Raman and NIR spectra of both the raw material and the commercial products were analyzed and their characteristic bands were tabulated. The best methods for TCZ identification in ovules were DSC, TG, XRD, NIR and Raman, while NIR and FTIR-ATR were the most appropriate techniques to analyze it in the nail lacquer. DSC, TG, DRX, Raman, FTIR-ATR and NIR spectroscopy are effective techniques to be used in online process analysis, because they do not require sample preparation, and they are considerably sensitive to analyze complex samples.

Mucoadhesive Properties of Eudragit®RS100, Eudragit®S100, and Poly(ε-caprolactone) Nanocapsules: Influence of the Vehicle and the Mucosal Surface

The use of polymers as mucoadhesive materials has been explored in several drug delivery systems. It is well known that the resulting mucoadhesiveness not only depends on the polymers by themselves, but also on the way they are delivered and on the application target. However, little attention has been given to the combined effect of such characteristics. Therefore, the objective of this study is to analyze the mucoadhesion resulting from combined effects of nanocapsules produced with polymers of different ionic properties, Eudragit®RS100, Eudragit®S100, or poly(ε-caprolactone), when they are incorporated into different vehicles (suspension, hydrogel, and powder) and applied on different mucosal surfaces (mucin, porcine vaginal, and buccal mucosa). Mucoadhesion was measured by a tensile stress tester. Our findings show that polymeric self-assembling as nanocapsules improved the mucoadhesion of the polymers. Eudragit®RS100 nanocapsules have the best performance, independently of the vehicle and surface used. Regarding the vehicle, hydrogels showed higher adhesion when compared to suspensions and powders. When considering different types of surfaces, mucin presented a similar pattern like the animal mucosa, but it overestimated the mucoadhesiveness of all formulations. In conclusion, this study demonstrated that the best strategy to achieve high mucoadhesive formulations is by incorporating Eudragit®RS100 nanocapsules in hydrogels. Moreover, mucin is a suitable substrate to compare and screen different formulations but not as a conclusive estimation of the mucoadhesion values that can be achieved. These results are summarized in a decision tree that can help to understand different strategies of combination of these factors and the expected outcomes.

Hesperetin-loaded lipid-core nanocapsules in polyamide: a new textile formulation for topical drug delivery

Chronic venous insufficiency is characterized by chronic reflux disorder of blood from the peripheral to the central vein, with subsequent venous hypertension and resulting changes in the skin. Traditionally, nonsurgical treatments relied on the use of compression therapy, and more recently a variety of flavonoids have been shown to have positive effects. There have also been developments of more effective drug delivery systems using various textiles and nanotechnology to provide new therapeutic options. Our objective was to use nanotechnology to develop a new formulation containing hesperetin (Hst), a substance not previously used in the treatment of chronic venous insufficiency, impregnated into textile fibers as a possible alternative treatment of venous diseases. We prepared the nanocapsules using the interfacial deposition of preformed polymer method with an Hst concentration of 0.5 mg/mL and then characterized the size and distribution of particles. To quantify the Hst in the samples, we developed an analytical method using high-performance liquid chromatography. Studies of encapsulation efficiency (98.81%±0.28%), microscopy, drug release (free-Hst: 104.96%±12.83%; lipid-core nanocapsule-Hst: 69.90%±1.33%), penetration/permeation, drug content (0.46±0.01 mg/mL) and the effect of washing the textile after drug impregnation were performed as part of the study. The results showed that nanoparticles of a suitable size and distribution with controlled release of the drug and penetration/permeation into the skin layers were achieved. Furthermore, it was established that polyamide was able to hold more of the drug, with a 2.54 times higher content than the cotton fiber; after one wash and after five washes, this relation was 2.80 times higher. In conclusion, this is a promising therapeutic alternative to be further studied in clinical trials.

An innovative polysaccharide nanobased nail formulation for improvement of onychomycosis treatment

Tioconazole-loaded nanocapsule suspensions and its coating with a cationic polymer were developed for nail drug delivery. The colloidal systems presented a nanometric size around 155nm for uncoated nanoparticles and 162nm for those with the cationic coating, with negative and positive zeta potential values, respectively. Both nanosuspensions showed drug content close to theoretical values (1mgmL^-1), association efficiency close to 100% (HPLC) and were able to control tioconazol release. The developed formulations showed in vitro antifungal activity (agar diffusion method) against C. albicans. The cationic nanocapsules were considered bioadhesive, showed higher viscosity and were chosen to be incorporated into an ungueal formulation. Pullulan nanobased nail formulation showed adequate viscosity for nail application and drug content close to the theoretical values. It was equivalent to the commercial formulation Trosid^® in preventing nail infection by T. rubrum in an in vitro onychomycosis model. The nanocapsule suspensions and Pullulan nanobased nail formulation showed lower irritant potential than the commercial formulation and than free drug in an in vitro evaluation. Pullulan nanobased nail formulation is promising for the treatment of onychomycosis.