New perspectives in the topical delivery of optimized amphotericin B loaded nanoemulsions using excipients with innate anti-fungal activities: A mechanistic and histopathological investigation

Polyene macrolide antibiotic nanoemulsion: a proposal for the treatment of cutaneous leishmaniasis

Leishmaniasis is a neglected tropical disease that requires timely and inexpensive treatment. For this purpose, a nanoemulsion with a polyene macrolide antibiotic, or amphotericin B (NE-AmB), was developed. This study quantified the amount of drug permeated and retained in intact and lacerated human skin, simulating cutaneous leishmaniasis (CL) processes. Toxicity in macrophage and keratinocyte cell lines, activity against promastigotes and amastigotes of Leishmania tropica, in vivo irritant activity, and histological evidence was evaluated. Results. The amount of drug retained in intact and damaged skin was 750.18 ± 5.43 and 567.97 ± 8.64 µg/g/cm2, respectively. There was no permeation. No apparent toxic effect was observed in HaCaT cell lines. The IC50 of NE-AmB found for promastigotes and amastigotes was 0.26 ± 0.09 and 0.37 ± 0.05 µg/mL, respectively. NE without AmB did show antiparasitic activity. The formulation showed lower IC50 values on both parasite stages than the AmB solution. There was no skin irritation, and histology showed skin improvement with treatment. We suggest that this NE-AmB may be a candidate for in vivo studies in CL patients. Keywords. Leishmaniasis, Amphotericin B, ex vivo permeation studies, in vitro cytotoxicity, in vitro leishmanicidal activity, Draize test, histology.

Review on Nanomaterials and Nano-Scaled Systems for Topical and Systemic Delivery of Antifungal Drugs

Fungal infections are human infections that topically affect the skin, mucous membranes, or more serious, invasive, and systemic diseases of the internal organs. The design and advancement of the formulation and approach of administration for therapeutic agents depend on many variables. The correlation between the formulations, mode of administration, pharmacokinetics, toxicity and clinical indication must be thoroughly studied for the successful evolution of suitable drug delivery systems. There are several NP formulations that serve as good delivery approaches for antifungal drugs. This paper covers various groups of nanoparticles utilized in antifungal drug delivery, such as phospholipid-based vesicles (nanovesicles), non-phospholipid vesicles, polymeric nanoparticles, inorganic nanoparticles and dendrimers, whereby their advantages and drawbacks are emphasized. Many in vitro or cell culture studies with NP formulations achieve an adequate high drug-loading capacity; they do not reach the clinically significant concentrations anticipated for in vivo studies. Because of this, the transfer of these nano-formulations from the laboratory to the clinic could be aided by focusing studies on overcoming problems related to nanoparticle stability, drug loading, and high production and standardization costs.

Development of Gum-Acacia-Stabilized Silver Nanoparticles Gel of Rutin against Candida albicans

Candida spp. is one of the most causative pathogens responsible for fungal infections. It is often a hospital-acquired form of sepsis with a very high number of deaths. Currently, the most effective anti-fungal agents are based on polyenes or echinocandins. However, long-term treatments or repeated use of these anti-fungals lead to therapy limitations. Current research is urgently needed to overcome existing challenges for antimicrobials from natural sources. This study aims to determine the anti-fungal activity of rutin, which has the advantage of increasing the therapeutic value. Because of its low solubility in water and oils, rutin is limited in use. To address these constraints, we encapsulated rutin in a nanocarrier system. Silver nanoparticles (SNPs) and gum acacia (GAs) are emerging as attractive components and are widely studied as biologically safe nanomaterials/carrier systems for various drugs. Still, they are barely investigated as nano-sized vectors for the targeted delivery of rutin. In the present work, GA stabilised SNPs of rutin were successfully formulated and evaluated. It was later incorporated into carbapol 940 gels and formed SNP gels. Rutin-SNPs were developed with a consistent size in the nano range of 59.67 ± 44.24 nm in size, 0.295 ± 0.014 polydispersity index (PDI), and −11.2 ± 6.66 mV zeta potential. The drug released was found to be 81. 26 ± 4.06% in 600 min by following zero-order kinetics. The rutin-SNP gel showed considerable activity against C. albicans skin candidiasis at MIC 1.56 g/mL. The developed formulation was biocompatible. This first-ever interdisciplinary study suggests that the rutin-SNPs gel could play a vital role in drug resistance in this fungal pathogen.

Antifungal Cationic Nanoemulsion Ferrying Miconazole Nitrate with Synergism to Control Fungal Infections: In Vitro, Ex Vivo, and In Vivo Evaluations

This study aimed to deliver a cationic nanoemulsion carrying miconazole nitrate (MCN) to control fungal infections using excipients for synergism. Peceol (oil) and labrasol (surfactant) were selected based on maximum solubility and zone of inhibition values against Candida albicans and Aspergillus niger. Optimized MCNE11 was evaluated [size, zeta potential, % entrapment efficiency (%EE), % transmittance, viscosity, refractive index, extrudability, polydispersity (PDI), morphology, and pH]. An in vitro drug release study was conducted for comparison between DS (drug suspension) and MNE11. In vitro hemolysis was studied at two different concentrations (0.625 and 2.5 μg/mL). Permeation profiles were generated using rat skin. A Draize test was conducted using rabbit to negate irritability issues. Finally, a stability test of MCNE11 was conducted for 12 months. The results showed that MCNE11 (cationic) was the most optimized in term of size, %EE, and PDI. The drug release from MCNE11 was higher compared to DS but comparable to MNE11 (anionic), suggesting no impact of the imposed cationic charge on the release behavior. Moreover, permeation parameters of MCNE11 were significantly (p < 0.05) greater than MNE11, which may be attributed to the combined impact of size (low), surfactant (for reversible changes), and electrostatic interaction (nanoglobules-skin surface). Thus, stable MCN11 possessing high %EE (89.8%), low size (145 nm), maximum flux (5.7 ± 0.1 μg/cm²/h), high drug deposition (932.7 ± 41.6 μg/cm²), optimal viscosity (44.17 ± 0.8 cP), low PDI (0.21), optimal zeta potential (+28.1 mV), and low hemolysis can be promising alternatives to conventional cream to control resistant and recurring types of fungal infections.

Olive oil and clove oil-based nanoemulsion for topical delivery of terbinafine hydrochloride: in vitro and ex vivo evaluation

In this article, formulation studies for terbinafine hydrochloride nanoemulsions, prepared by high-energy ultrasonication technique, are described. Pseudo-ternary phase diagram was constructed in order to find out the optimal ratios of oil and surfactant/co-solvent mixture for nanoemulsion production. Clove and olive oils were selected as oil phase. Based on the droplet size evaluation, maximum nanoemulsion region were determined for formulation development. Further characterization included polydispersity index (PDI), zeta potential, Fourier transform infrared (FT-IR) spectroscopy, morphology, pH, viscosity, refractive index, ex vivo skin permeation, skin irritation, and histopathological examination. Droplet sizes of optimized formulations were in colloidal range. PDI values below 0.35 indicated considerably homogeneous nanoemulsions. Zeta potential values were from 13.2 to 18.1 mV indicating good stability, which was also confirmed by dispersion stability studies. Ex vivo permeation studies revealed almost total skin permeation of terbinafine hydrochloride from the nanoemulsions (96–98%) in 6 hours whereas commercial product reached only 57% permeation at the same time. Maximum drug amounts were seen in epidermis and dermis layers. Skin irritation and histopathological examination demonstrated dermatologically safe formulations. In conclusion, olive oil and clove oil-based nanoemulsion systems have potential to serve as promising carriers for topical terbinafine hydrochloride delivery.

Nanoemulsion delivery systems for enhanced efficacy of antimicrobials and essential oils

The ever-growing threat of new and existing infectious diseases in combination with antimicrobial resistance requires the need for innovative and effective forms of drug delivery. Optimal drug delivery systems for existing and newly developed antimicrobials can enhance drug bioavailability, enable site-specific drug targeting, and overcome current limitations of drug formulations such as short elimination half-lives, poor drug solubility, and undesirable side effects. Nanoemulsions (NE) consist of nanometer-sized droplets stabilized by emulsifiers and are typically more stable and permeable due to their smaller particle sizes and higher surface area compared to conventional emulsions. NE have been identified as a promising means of antimicrobial delivery due to their intrinsic antimicrobial properties, ability to increase drug solubility, stability, bioavailability, organ and cellular targeting potentials, capability of targeting biofilms, and potential to overcome antimicrobial resistance. Herein, we discuss non-drug loaded essential oil-based NE that can confer antimicrobial actions through predominantly physical or biochemical mechanisms without drug payloads. We also describe drug-loaded NE for enhanced antimicrobial efficacy by augmenting the potency of existing antimicrobials. We highlight the versatility of NE to be administered through multiple different routes (oral, parenteral, dermal, transdermal, pulmonary, nasal, ocular, and rectal). We summarize recent advances in the clinical translation of antimicrobial NE and shed light on future development of effective antimicrobial therapy to combat infectious diseases.

Nanoemulsion-based dissolving microneedle arrays for enhanced intradermal and transdermal delivery

The development of dissolving microneedles (DMN) is one of the advanced technologies in transdermal drug delivery systems, which precisely deliver the drugs through a rapid dissolution of polymers after insertion into the skin. In this study, we fabricated nanoemulsion-loaded dissolving microneedle (DMN) arrays for intradermal and transdermal drug delivery. For this task, model drug (amphotericin B, AmB)-loaded nanoemulsion (NE) were prepared by the probe-sonication method. AmB-loaded-NE was prepared using Capmul MCM C-8 EP/NF, Tween^® 80, poly(vinyl alcohol) (PVA-10 kDa), and poly (vinyl pyrrolidone) (PVP-360 kDa or K29/32) by using SpeedMixer™, followed by probe-sonication and evaluated for particle size and polydispersity index (PDI). Transmission electron microscopy (TEM) was also used to assess the particle size before and after DMN casting. AmB-NE embedded DMN arrays were found to be strong enough, revealed efficient skin insertion, and penetrated down to the fourth layer (depth ≈ 508 μm) of Parafilm M^® (validated skin model). Ex vivo skin deposition experiments in full-thickness neonatal porcine demonstrated that after 24 h, AmB-NE-DMN arrays were able to deposit 111.05 ± 48.4 µg/patch AmB into the skin. At the same time, transdermal porcine skin permeation studies showed significantly higher permeability of AmB (29.60 ± 8.23 μg/patch) from AmB-NE-DMN compared to MN-free AmB-NE patches (5.0 ± 6.15 μg/patch) over 24 h. Antifungal studies of optimized AmB-NE-DMN, AmB-loaded discs and drug-free DMN against Candida albicans, confirmed the synergistic activity of Campul-MCM C-8, used in the nanoemulsion formulation. This study establishes that nanoemulsion based dissolving microneedle may serve as an efficient system for intradermal as well as transdermal drug delivery.

Dissolving microneedle patches loaded with amphotericin B microparticles for localised and sustained intradermal delivery: Potential for enhanced treatment of cutaneous fungal infections

Fungal infections affect millions of people globally and are often unreceptive to conventional topical or oral preparations because of low drug bioavailability at the infection site, lack of sustained therapeutic effect, and the development of drug resistance. Amphotericin B (AmB) is one of the most potent antifungal agents. It is increasingly important since fungal co-infections associated with COVID-19 are frequently reported. AmB is only administered via injections (IV) and restricted to life-threatening infections due to its nephrotoxicity and administration-related side effects. In this work, we introduce, for the first time, dissolving microneedle patches (DMP) loaded with micronised particles of AmB to achieve localised and long-acting intradermal delivery of AmB for treatment of cutaneous fungal infections. AmB was pulverised with poly (vinyl alcohol) and poly (vinyl pyrrolidone) to form micronised particles-loaded gels, which were then cast into DMP moulds to form the tips. The mean particle size of AmB in AmB DMP tips after pulverisation was 1.67 ± 0.01 μm. This is an easy way to fabricate and load microparticles into DMP, as few steps are required, and no organic solvents are needed. AmB had no covalent chemical interaction with the excipients, but the crystallinity of AmB was reduced in the tips. AmB was completely released from the tips within 4 days in vitro. AmB DMP presented inhibition of Candida albicans (CA) and the killing rate of AmB DMP against CA biofilm inside porcine skin reached 100% within 24 h. AmB DMP were able to pierce excised neonatal porcine skin at an insertion depth of 301.34 ± 46.86 μm. Ex vivo dermatokinetic and drug deposition studies showed that AmB was mainly deposited in the dermis. An in vivo dermatokinetic study revealed that the area under curve (AUC_0-inf) values of AmB DMP and IV (Fungizone® bolus injection 1 mg/kg) groups were 8823.0 d∙μg/g and 33.4 d∙μg/g, respectively (264-fold higher). AmB remained at high levels (219.07 ± 102.81 μg/g or more) in the skin until 7 days after the application of AmB DMP. Pharmacokinetic and biodistribution studies showed that AmB concentration in plasma, kidney, liver, and spleen in the AmB DMP group was significantly lower than that in the IV group. Accordingly, this system addressed the systemic side effects of intravenous injection of AmB and localised the drug inside the skin for a week. This work establishes a novel, easy and effective method for long-acting and localised intradermal drug delivery.

Relationship and improvement strategies between drug nanocarrier characteristics and hemocompatibility: What can we learn from the literature

This article discusses the various blood interactions that may occur with various types of nano drug-loading systems. Nanoparticles enter the blood circulation as foreign objects. On the one hand, they may cause a series of inflammatory reactions and immune reactions, resulting in the rapid elimination of immune cells and the reticuloendothelial system, affecting their durability in the blood circulation. On the other hand, the premise of the drug-carrying system to play a therapeutic role depends on whether they cause coagulation and platelet activation, the absence of hemolysis and the elimination of immune cells. For different forms of nano drug-carrying systems, we can find the characteristics, elements and coping strategies of adverse blood reactions that we can find in previous researches. These adverse reactions may include destruction of blood cells, abnormal coagulation system, abnormal effects of plasma proteins, abnormal blood cell behavior, adverse immune and inflammatory reactions, and excessive vascular stimulation. In order to provide help for future research and formulation work on the blood compatibility of nano drug carriers.

Delivery strategies of amphotericin B for invasive fungal infections

Invasive fungal infections (IFIs) represent a growing public concern for clinicians to manage in many medical settings, with substantial associated morbidities and mortalities. Among many current therapeutic options for the treatment of IFIs, amphotericin B (AmB) is the most frequently used drug. AmB is considered as a first-line drug in the clinic that has strong antifungal activity and less resistance. In this review, we summarized the most promising research efforts on nanocarriers for AmB delivery and highlighted their efficacy and safety for treating IFIs. We have also discussed the mechanism of actions of AmB, rationale for treating IFIs, and recent advances in formulating AmB for clinical use. Finally, this review discusses some practical considerations and provides recommendations for future studies in applying AmB for combating IFIs.

Therapies and Vaccines Based on Nanoparticles for the Treatment of Systemic Fungal Infections

Treatment modalities for systemic mycoses are still limited. Currently, the main antifungal therapeutics include polyenes, azoles, and echinocandins. However, even in the setting of appropriate administration of antifungals, mortality rates remain unacceptably high. Moreover, antifungal therapy is expensive, treatment periods can range from weeks to years, and toxicity is also a serious concern. In recent years, the increased number of immunocompromised individuals has contributed to the high global incidence of systemic fungal infections. Given the high morbidity and mortality rates, the complexity of treatment strategies, drug toxicity, and the worldwide burden of disease, there is a need for new and efficient therapeutic means to combat invasive mycoses. One promising avenue that is actively being pursued is nanotechnology, to develop new antifungal therapies and efficient vaccines, since it allows for a targeted delivery of drugs and antigens, which can reduce toxicity and treatment costs. The goal of this review is to discuss studies using nanoparticles to develop new therapeutic options, including vaccination methods, to combat systemic mycoses caused by Candida sp., Cryptococcus sp., Paracoccidioides sp., Histoplasma sp., Coccidioides sp., and Aspergillus sp., in addition to providing important information on the use of different types of nanoparticles, nanocarriers and their corresponding mechanisms of action.

Novel Approach for Transdermal Delivery of Rifampicin to Induce Synergistic Antimycobacterial Effects Against Cutaneous and Systemic Tuberculosis Using a Cationic Nanoemulsion Gel

Purpose

This study demonstrated improved transdermal delivery of rifampicin-loaded cationic nanoemulsion gel to treat systemic and cutaneous tuberculosis using capmul, labrasol, and acconon, which exert anti-Mycobacterium activities. This approach enhanced drug permeation across the skin, increased therapeutic efficacy, and reduced dose-related side effects.

Methods

Design Expert^® was used to optimize formulations (S_mix ratio and capmul as independent factors), which were prepared using a slow spontaneous titration method. The optimized nanoemulsion was incorporated into carbopol gel to allow for topical application and comparative assessments. Nanoemulsions and gels were evaluated for size, size distribution, shape, zeta potential, percent spread, viscosity, in vitro hemolysis, in vitro release, and ex vivo skin permeation and deposition. A mechanistic evaluation was performed using scanning electron microscopy. Furthermore, in vivo pharmacokinetic and irritation studies were performed.

Results

The optimized cationic nanoemulsion (OCNE-1) was characterized by small particle size (≤100 nm), had optimal viscosity, percent spread, zeta potential, and percent drug release, and was hemocompatible. The OCNE-1T gel exhibited higher permeation flux (51.32 ± 0.5 µg/cm² hr), permeation coefficient (2.566 ± 0.08 cm/hr), drug deposition (994.404 µg/cm²), and enhancement ratio (7.16) than those of the OCNE-1 nanoemulsion or drug solution. Scanning electron microscopy was used to characterize the mechanism of enhanced permeation. An In vivo study showed that the C_max and area under the curve following transdermal application were 4.34- and 4.74-fold higher than those following oral administration.

Conclusion

Transdermal delivery of rifampicin could be a promising alternative to conventional approaches to treat systemic and local tuberculosis, and other bacterial infections.

Topical Amphotericin B Semisolid Dosage Form for Cutaneous Leishmaniasis: Physicochemical Characterization, Ex Vivo Skin Permeation and Biological Activity

Amphotericin B (AmB) is a potent antifungal successfully used intravenously to treat visceral leishmaniasis but depending on the Leishmania infecting species, it is not always recommended against cutaneous leishmaniasis (CL). To address the need for alternative topical treatments of CL, the aim of this study was to elaborate and characterize an AmB gel. The physicochemical properties, stability, rheology and in vivo tolerance were assayed. Release and permeation studies were performed on nylon membranes and human skin, respectively. Toxicity was evaluated in macrophage and keratinocyte cell lines, and the activity against promastigotes and intracellular amastigotes of Leishmania infantum was studied. The AmB gel remained stable for a period of two months, with optimal properties for topical use and no apparent toxic effect on the cell lines. High amounts of AmB were found in damaged and non-damaged skin (1230.10 ± 331.52 and 2484.57 ± 439.12 µg/g/cm², respectively) and they were above the IC₅₀ of AmB for amastigotes. Although there were no differences in the in vitro anti-leishmanial activity between the AmB solution and gel, the formulation resulted in a higher amount of AmB being retained in the skin, and is therefore a candidate for further studies of in vivo efficacy.

Lipid Systems for the Delivery of Amphotericin B in Antifungal Therapy

Amphotericin B (AmB), a broad-spectrum polyene antibiotic in the clinic for more than fifty years, remains the gold standard in the treatment of life-threatening invasive fungal infections and visceral leishmaniasis. Due to its poor water solubility and membrane permeability, AmB is conventionally formulated with deoxycholate as a micellar suspension for intravenous administration, but severe infusion-related side effects and nephrotoxicity hamper its therapeutic potential. Lipid-based formulations, such as liposomal AmB, have been developed which significantly reduce the toxic side effects of the drug. However, their high cost and the need for parenteral administration limit their widespread use. Therefore, delivery systems that can retain or even enhance antimicrobial efficacy while simultaneously reducing AmB adverse events are an active area of research. Among those, lipid systems have been extensively investigated due to the high affinity of AmB for binding lipids. The development of a safe and cost-effective oral formulation able to improve drug accessibility would be a major breakthrough, and several lipid systems for the oral delivery of AmB are currently under development. This review summarizes recent advances in lipid-based systems for targeted delivery of AmB focusing on non-parenteral nanoparticulate formulations mainly investigated over the last five years and highlighting those that are currently in clinical trials.

Topical Drug Delivery of Anti-infectives Employing Lipid-Based Nanocarriers: Dermatokinetics as an Important Tool

BACKGROUND

The therapeutic approaches for the management of topical infections have always been a difficult approach due to lack of efficacy of conventional topical formulations, high frequency of topical applications and non-patient compliance. The major challenge in the management of topical infections lies in antibiotic resistance which leads to severe complications and hospitalizations resulting in economic burden and high mortality rates.

METHODS

Topical delivery employing lipid-based carriers has been a promising strategy to overcome the challenges of poor skin permeation and retention along with large doses which need to be administered systemically. The use of lipid-based delivery systems is a promising strategy for the effective topical delivery of antibiotics and overcoming drug-resistant strains in the skin. The major systems include transfersomes, niosomes, ethosomes, solid lipid nanoparticles, nanostructured lipid carriers, microemulsion and nanoemulsion as the most promising drug delivery approaches to treat infectious disorders. The main advantages of these systems include lipid bilayer structure which mimics the cell membrane and can fuse with infectious microbes. The numerous advantages associated with nanocarriers like enhanced efficacy, improvement in bioavailability, controlled drug release and ability to target the desired infectious pathogen have made these carriers successful.

CONCLUSION

Despite the number of strides taken in the field of topical drug delivery in infectious diseases, it still requires extensive research efforts to have a better perspective of the factors that influence drug permeation along with the mechanism of action with regard to skin penetration and deposition. The final objective of the therapy is to provide a safe and effective therapeutic approach for the management of infectious diseases affecting topical sites leading to enhanced therapeutic efficacy and patient-compliance.

Role of architecture of N-oxide surfactants in the design of nanoemulsions for Candida skin infection

In this work we present comprehensive research on the formation, stability and structural properties of oil-in-water (o/w) nanoemulsions with the ability for topical administration, penetration of the skin and acting as antifungal agents against C. albicans. The studied nanoemulsions were composed of different ratios of double-head - single-tail surfactants {1-bis{[3-(N,N-dimethylamino)ethyl]amido}alkane-di-N-oxides (C_n-MEDA), N,N-bis[3,3'-(dimethyl-amino)propyl]alkyl-amide di-N-oxides (C_n(DAPANO)₂} and single-head - single-tail surfactants {2-(alkanoylamino)-ethyldimethyl-amine-N-oxides (C_n-EDA), and 3-(alkanoylamino) propyldimethylamine-N-oxides, (C_n-PDA)} added to the oil {isooctane IO, isopropyl myristate IPM or glyceryl monocaprylate GM as (O)} and to the water phase (W). The phase behavior of the systems was examined by a titration method. Morphology of the resulting colloids was characterized by scanning and transmission electron microscopy, the particle size and size distributions determined by dynamic light scattering, and kinetic stability by multiple light scattering. While both surfactant types resulted in quite stable nanoemulsions, the systems formed using a single-headed one-tail surfactant were slightly more stable with GM or IPM. The microenvironmental properties of the nanoemulsions were studied by an electron paramagnetic resonance technique to distinguish the molecular dynamics of the different spin probes localized in the particular regions of the surfactant layers, depending on the surfactant structure and the system preparation. Skin permeation studies were performed to monitor transport through the skin, and changes in skin structure were followed using differential scanning calorimetry. Moreover, the activities of curcumin-loaded nanoemulsions stabilized by N-oxide surfactants against Candida albicans fungus were evaluated. To estimate in vitro efficacy, the suitability of an N-oxide nanoemulsion dressing against wound infection with biofilm C. albicans was assessed according to the Antibiofilm Dressing's Activity Measurement. We expect that the nanoemulsion formulations tested in this study will have potential for application as topical delivery systems for pharmaceutically active compounds in skin-related conditions.

Development of sulconazole-loaded nanoemulsions for enhancement of transdermal permeation and antifungal activity

Background: Sulconazole (SCZ) is a broad-spectrum transdermally administered anti-fungicidal agent. However, the therapeutic effect of SCZ is generally limited by its poor water solubility. This present study aimed to develop and evaluate sulconazole-loaded nanoemulsions (SCZ-NEs) for enhancement of the transdermal permeation and antifungal activity. Methods: A spontaneous titration method was applied to prepare the SCZ-NEs. And the optimized formulation of SCZ-NEs was screened by central composite design (CCD). In addition, the characteristics of the SCZ-NEs were evaluated, including particle size, zeta potential, drug loading (DL%) and encapsulation efficiency (EE%). The morphology of SCZ-NEs was observed by transmission electron microscopy (TEM). Franz diffusion cells were used to evaluate the transdermal permeability of the SCZ-NEs. The antifungal activity of the SCZ-NEs was measured by a zone of inhibition (ZOI) test. Results: The optimized SCZ-NEs possessed a moderate particle size of 52.3±3.8 nm, zeta potential of 23.3±1.2 mV, DL% of 0.47±0.05% and EE% of 87.1±3.2%. The ex vivo skin permeation study verified that the cumulative permeability (Qn) and penetration rate (Js) of the optimized SCZ-NEs were about 1.7-fold higher than that of a commercial reference, miconazole (MCZ) cream and 3-fold higher than that of SCZ-DMSO solution. The optimized SCZ-NEs exhibited zone of inhibition (ZOI) values of 23.5±2.4 and 20.4±2.5 mm against C. albicans and T. rubrum, which were larger compared with these of the MCZ cream and SCZ-DMSO solution. Conclusion: SCZ-NEs were effectively developed to overcome the poor solubility of SCZ, promote SCZ permeation through the skin and improve its antifungal activity. Thus, the SCZ-NEs are a promising percutaneous administration for skin fungal infections induced by C. albicans and T. rubrum.

Solidified SNEDDS for the oral delivery of rifampicin: Evaluation, proof of concept, in vivo kinetics, and in silico GastroPlusTM simulation

The present investigation was performed to develop a rifampicin (RIF)-loaded solidified self-nanoemulsifying drug delivery system (SNEDDS) (solidified RIF-OF1) for in vitro and in vivo evaluations. Optimized formulations were tested for their powder flow characteristics, loading efficiency, and in vitro dissolution (at pH-1.2, 6.8 and 7.4). Compatibility studies were also performed. The formulations were also tested for hemocompatibility, intestinal permeation, histopathological effects, and in vivo pharmacokinetics. Additionally, an in silico simulation study using GastroPlus was performed. At different varied pH values, we observed immediate release (T_85% within 15 min) based on the dissolution profile. This could be due to labrasol-assisted RIF solubilization. In vitro hemolysis study of the reconstituted RIF-OF1 revealed normal architecture of erythrocytes compared to the positive control (lysed and fragmented). Through in vivo permeation and biopsy studies, a rationale for facilitated intestinal permeation of RIF with components deemed physiological safe (normal anatomy of mucosal membrane evidenced from biopsy study) could be established. The in vitro-in vivo correlation (IVIVC) plus module of GastroPlus^TM simulation showed a good IVIVC between in vitro release and in vivo absorption with a predicted systemic absorption of ∼96.5%. Solidified SNEDDS showed improved pharmacokinetic profiles compared to RIF suspension. Solid RIF-SNEDDS was demonstrated to be a suitable carrier for enhanced intestinal permeation and oral bioavailability. Hence, it may serve as a suitable alternative to conventional delivery systems for tuberculosis treatment.

Recent insights on nanomedicine for augmented infection control

Antimicrobial agents have been widely investigated for protecting against microbial infections in modern health. Drug-related limitations, poor bioavailability, toxicity to mammalian cells, and frequent bacteria drug resistance are major challenges faced when exploited in nanomedicine forms. Specific attention has been paid to control nanomaterial-based infection against numerous challenging pathogens in addition to improved drug delivery, targeting, and pharmacokinetic (PK) profiles, and thus, efficient antimicrobials have been fabricated using diverse components (metals, metal oxides, synthetic and semisynthetic polymers, natural or biodegradable polymers, etc). The present review covers several nanocarriers delivered through various routes of administration, highlighting major findings to control microbial infection as compared to using the free drug. Results over the past decade support the consistent development of various nanomedicines capable of improving biological significance and therapeutic benefits against an array of microbial strains. Depending on the intended application of nanomedicine, infection control will be challenged by various factors such as weighing the risk-benefits in healthcare settings, nanomaterial-induced (eco)toxicological hazards, frequent development of antibiotic resistance, scarcity of in vivo toxicity data, and a poor understanding of microbial interactions with nanomedicine at the molecular level. This review summarizes well-established informative data for nanomaterials used for infection control and safety concerns of nanomedicines to healthcare sectors followed by the significance of a unique "safe-by-design" approach.

α-Linolenic acid-modified pluronic 127-CS copolymeric micelles for the skin targeted delivery of amphotericin B

In this study, an α-linolenic acid modified pluronic F127-block-chitosan (F127-(CS-LNA)₂) copolymer was synthesized to prepare topical amphotericin B (AMB)-loaded micelles (AMB-M) via a dialysis technique.

Understanding the prospective of nano-formulations towards the treatment of psoriasis

Psoriasis is a consistently recurring, inflammatory, autoimmune disorder of the skin, affecting about 2-5% of the world population. Abundant therapeutic agents are accessible for the treatment of psoriasis. Nevertheless, none of them are entirely secure and effective to treat the disease without compromising patient compliance. Furthermore, already existing drugs are supposed to restrain the ailment and alleviate the sign and symptoms with no complete cure. However, they focus on restraining the disease and alleviating the symptoms without providing an absolute cure. Therefore there remains a vital challenge, to explore a new drug moiety or delivery system which could safely and effectively manage psoriasis without compromising patient compliance. Furthermore, conventional formulations offer reduced benefit/risk ratio of anti-psoriatic drugs, which limits the use of existing conventional formulations. Novel formulations based on nanocarriers are a promising prospect to overcome the limitation of conventional formulations by offering a reduction in dose, dosing frequency, dose-dependent, side effects with enhanced efficacy. Presently nano-formulations have gained widespread application for effective and safe treatment of psoriasis. The present review primarily focuses on conventional therapeutic strategy and recent advances in lipid-based, polymer-based and metallic nano-formulations of a variety of anti-psoriatic drugs. The practicability of various nanocarrier systems including liposomes, nanostructured lipid carriers, ethosomes, solid lipid nanoparticles, nanocapsules, micelles, dendrimers, gold nanoparticles and silver nanoparticles have been discussed in detail. The review also traces related patents to exemplify the role of various nanoparticles in psoriasis treatment. In a nutshell, nano-formulations remain established as a promising modality for treating psoriasis treatment as they propose better penetration, targeted delivery, enhanced safety, and efficacy.

Nanoemulsions and dermatological diseases: contributions and therapeutic advances

Skin disease is one of the most common human diseases and affects between 30% and 70% of individuals, which requires a lot of attention to their treatments. The delivery of active pharmacological ingredients at the topical level is a challenge because of the difficulties in overcoming the mechanical barrier created by the skin and reaching greater depths, since delivery specificities are decisive for the degree of effectiveness. In this way, the nanoemulsions emerge as a potential system for the incorporation of active substances in the cells and for the controlled release of active principles. The present article intends to review the main treatments for which the nanoemulsions were used in the field of dermatology. In addition, it discusses the results and advantages over the other dermatological therapies that are being used. The results showed that the particle size in nanoemulsions increased the contact surface area, resulting in increased drug efficacy, even in comparison with other existing pharmaceutical formulations. In conclusion, it has been shown that nanoemulsions have a better performance in efficacy, safety, permeability profile, and bioavailability compared with other formulations studied.

Nanoparticles as safe and effective delivery systems of antifungal agents: Achievements and challenges

Invasive fungal infections are becoming a major health concern in several groups of patients leading to severe morbidity and mortality. Moreover, cutaneous fungal infections are a major cause of visits to outpatient dermatology clinics. Despite the availability of several effective agents in the antifungal drug arena, their therapeutic outcome is less than optimal due to limitations related to drug physicochemical properties and toxicity. For instance, poor aqueous solubility limits the formulation options and efficacy of several azole antifungal drugs while toxicity limits the benefits of many other drugs. Nanoparticles hold great promise to overcome these limitations due to their ability to enhance drug aqueous solubility, bioavailability and antifungal efficacy. Further, drug incorporation into nanoparticles could greatly reduce its toxicity. Despite these interesting nanoparticle features, there are only few marketed nanoparticle-based antifungal drug formulations. This review sheds light on different classes of nanoparticles used in antifungal drug delivery, such as lipid-based vesicles, polymeric micelles, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions and dendrimers with emphasis on their advantages and limitations. Translation of these nanoformulations from the lab to the clinic could be facilitated by focusing the research on overcoming problems related to nanoparticle stability, drug loading and high cost of production and standardization.

Nanoemulsion: Concepts, development and applications in drug delivery

Nanoemulsions are biphasic dispersion of two immiscible liquids: either water in oil (W/O) or oil in water (O/W) droplets stabilized by an amphiphilic surfactant. These come across as ultrafine dispersions whose differential drug loading; viscoelastic as well as visual properties can cater to a wide range of functionalities including drug delivery. However there is still relatively narrow insight regarding development, manufacturing, fabrication and manipulation of nanoemulsions which primarily stems from the fact that conventional aspects of emulsion formation and stabilization only partially apply to nanoemulsions. This general deficiency sets up the premise for current review. We attempt to explore varying intricacies, excipients, manufacturing techniques and their underlying principles, production conditions, structural dynamics, prevalent destabilization mechanisms, and drug delivery applications of nanoemulsions to spike interest of those contemplating a foray in this field.