Atorvastatin-loaded emulsomes foam as a topical antifungal formulation.

Dermal fungal infection faces many challenges, especially for immunocompromised patients. Recently, the repositioning of atorvastatin (ATO) as a promising anti-mycoses therapy is used to overcome some issues of conventional therapeutic agents such as microbial resistance. The goal of this study was to develop a suitable formula for dermal fungal infection. Wherefore, ATO was entrapped into emulsomes and then incorporated in a foam system for topical convenient application. The D-optimal design was used for the optimization of ATO-emulsome and foam to achieve suitable responses. Regarding emulsomes, cholesterol weight and sonication time were independent variables that impact emulsome size, polydispersity index, surface charge, and entrapment efficiency. The optimum formula showed a size of 359.4 ± 8.97 nm, PDI of 0.4752 ± 0.012, a zeta potential of -21.27 ± 0.53 mV, and a drug entrapment of 95 ± 2.38%. Transmission electron microscope and Fourier-transform infrared spectroscopy (FT-IR) proved the assembly of ATO-emulsome. Foam composition was optimized to achieve good expansion, stability, and viscosity using a surfactant triple mixture and hydroxypropyl methylcellulose. The selected ATO-emulsome foam which consisted of 1% HPMC, 1.249% SDS, and 4% pluronic showed prolonged drug release. Efficient permeation through skin layers was asserted by using a confocal laser scanning microscope. Moreover, the homogenous distribution of the foam bubbles upholds stability and conserves the system from rapid collapse. The antifungal activity was confirmed by an in-vitro and in-vivo microbiology study beside in-vivo biocompatibility. In conclusion, ATO-emulsome and incorporation in foam have demonstrated good antifungal activity which presented a unique aspect for potential clinical applications.

Repurposing of atorvastatin emulsomes as a topical antifungal agent.

Cutaneous fungal infection therapy confronts several issues concerning skin permeation in addition to drug resistance and adverse effects of conventional drugs. The repurposing strategy is supposed to overcome some of those therapeutic obstacles. Recently, atorvastatin (ATO) revealed antifungal activity. ATO is an antihyperlipidemic drug with pH-dependent solubility, which limits skin permeation. This study aims to improve ATO antifungal activity by encapsulation in an emulsomes (EMLs) system, which seeks to ameliorate skin penetration. Therefore, multiple factors were investigated according to the One-Factor-at-a-Time (OFAT) design to achieve the optimum formula with targeted characteristics. Minimizing particle-size and polydispersity-index, besides elevating zeta-potential (ZP) and entrapment-efficiency were the desirable responses during assessing 11 factors. The selected ATO-EMLs formula (E21) recorded 250.5 nm in particle size, polydispersity index of 0.4, ZP of -25.93 mV, and 83.12% of drug entrapped. Morphological study of E21 revealed spherical core-shell vesicles in nanosize. DSC, XRD, and FTIR were conducted to discover the physicochemical properties and confirm emulsomes formation. Optimized ATO-EMLs slowed drug release rate as only 75% of ATO was released after 72 h. Stability study recommended storage between 2 and 8 °C. The in vivo permeation study remarked a homogeneous penetration of EMLs in different skin layers. The in vivo skin irritation test revealed limited histopathological changes. The in vitro and in vivo microbiological studies demonstrated a good antifungal activity of ATO-EMLs. ATO-EMLs system improved antifungal activity as the MIC values reduced from 650 µg/mL for free ATO to 550 µg/mL for ATO-EMLs. These findings may shed light on ATO as an antifungal drug and nanosystems as a tool to support drug repurposing.

Silica-Coated Magnetic Nanoparticles for Vancomycin Conjugation.

Drug resistance is a global health challenge with thousands of deaths annually caused by bacterial multidrug resistance (MDR). Efforts to develop new antibacterial molecules do not meet the mounting needs imposed by the evolution of MDR. An alternative approach to overcome this challenge is developing targeted formulations that can enhance the therapeutic efficiency and limit side effects. In this aspect, vancomycin is a potent antibacterial agent that has inherent bacterial targeting properties by binding to the D-Ala-D-Ala moiety of the bacterial peptidoglycan. However, the use of vancomycin is associated with serious side effects that limit its clinical use. Herein, we report the development of vancomycin-conjugated magnetic nanoparticles using a simple conjugation method for targeted antibacterial activity. The nanoparticles were synthesized using a multistep process that starts by coating the nanoparticles with a silica layer, followed by binding an amide linker and then binding the vancomycin glycopeptide. The developed vancomycin-conjugated magnetic nanoparticles were observed to exhibit a spherical morphology and a particle size of 16.3 ± 2.6 nm, with a silica coating thickness of 5 nm and a total coating thickness of 8 nm. The vancomycin conjugation efficiency on the nanoparticles was measured spectrophotometrically to be 25.1%. Additionally, the developed formulation retained the magnetic activity of the nanoparticles, where it showed a saturation magnetization value of 51 emu/g, compared to 60 emu/g for bare magnetic nanoparticles. The in vitro cell biocompatibility demonstrated improved safety where vancomycin-conjugated nanoparticles showed IC50 of 183.43 µg/mL, compared to a much lower value of 54.11 µg/mL for free vancomycin. While the antibacterial studies showed a comparable activity of the developed formulation, the minimum inhibitory concentration was 25 µg/mL, compared to 20 µg/mL for free vancomycin. Accordingly, the reported formulation can be used as a platform for the targeted and efficient delivery of other drugs.

Nanoparticles Loaded Thermoresponsive In Situ Gel for Ocular Antibiotic Delivery against Bacterial Keratitis.

Antibiotics delivered through conventional dosage against ophthalmic infections show lower therapeutic efficacy due to their low residence time. Therefore, there is a great need to design and develop novel dosage forms that would increase the ocular residence time of antibiotics at the site of infection. This study describes the development of nanoparticles laden in situ gelling solution, intended to sustain antibiotic release for improved therapeutic efficiency. Oxytetracycline-loaded gelatin-polyacrylic acid nanoparticles were prepared and incorporated in poloxamer-N407 solution. The rheological properties of the system were studied concerning time and temperature. Moreover, in vivo biocompatibility of the system was ascertained using the Draize test and histological studies. Finally, the optimized formulation was evaluated for in vitro antibacterial activity against one of the most common keratitis causing bacteria, Pseudomonas aeruginosa. Additionally, the in vivo efficacy was evaluated on the rabbit's eye conjunctivitis model. The formulation showed a sustained effect against keratitis; furthermore, the antibacterial activity was comparable with the commercial product.

Respirable spray dried vancomycin coated magnetic nanoparticles for localized lung delivery.

Bacterial pneumonia is a common pulmonary infection responsible for premature death. Biomaterials based-carriers loaded with antibiotics enhance drug potency through localizing the therapy, minimizing the associated adverse effects, and improving patient compliance. Herein, this study reports the preparation of an inhalable dry powder formulation composed of a nano-in-microparticles. Vancomycin was adsorbed on the core of magnetic nanoparticles followed by spray drying into lactose/dextran to optimize the aerodynamic performance and allow the local delivery of the drug into the bacterial pneumonia infection site. Lactose and Dextran are polysaccharides commonly used for pulmonary delivery due to their optimum aerodynamic performance and biocompatibility. The preparation of the nano-in-micro particles with optimum properties was confirmed using FTIR, TEM, SEM, Laser-diffraction, ICP-AES and TGA. The TEM micrographs confirmed the formation of spherical magnetic nanoparticles with a diameter 14.7 ± 5.9 nm and a coating thickness 3 - 16 nm, while laser diffraction showed that outer microparticles exhibited a mean diameter < 5 µm. The formulations demonstrated a promising activity against S. aureus and MRSA and better biocompatibility using MTT assay. In vivo safety and pharmacokinetic studies confirmed the localization of VAN in lung tissue and minimized adverse effects compared to free VAN. Therefore, the developed nano-in-microparticles confers a good potential for eradication of lung infections.