Alaa S. Eita

Background: Amlodipine besylate (AML) is recognized as a calcium channel blocker curative for hypertension. However, the drug emerged recently as an antibacterial cure that competently prevails over resistant strains. Methods: Incorporating amlodipine into zein nanoparticles was employed to innovate a suitable carrier for loading and targeting deep corneal infection. The Box–Behnken design was adopted to produce various formulations of amlodipine-loaded zein nanoparticles (AML-ZNs) with diversity in composition concentration (% w/v), comprising zein, Labrafac, and poloxamer 407. Results: Relying on the optimization criterion, the chosen preference formulation concentration (% w/v) consists of 2.068 for zein, 0.75 for Labrafac, and 1.0 for Poloxamer. Morphological micrography of AML-ZNs showed regular spherical particles in the nanometric scale, and physicochemical characterization procedures confirmed system suitability. While tracking eyedrop optimum features, sodium alginate was selected for coating nanoparticles to improve stability and system viscosity. Both pH and sterility were also considered and maintained. Comparative studies were conducted pre- and post-coating, and the assessed features for the final selected formulation were 349.9 ± 5.8 nm, 0.2186 ± 0.0271, −55.45 ± 1.84 mV, 81.293 ± 0.9%, and 19.3 ± 0.19 cp for size, PDI, surface charge, entrapment, and viscosity, respectively. The AML-ZNs-Alg formulation demonstrates a more controlled pattern of release of roughly 40% of the drug released after 48 h, while the permeation profile shows 37 ± 3.52% permeated after 24 h, confirmed visually. In vitro microbial assay alongside the corneal in vivo microbial and histological pathology evaluation proved the efficacy of amlodipine as an antibacterial agent. Conclusions: These findings highlighted that the prepared AML-ZNs-Alg eyedrop can be a promising system as an antibacterial therapy.

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.