Yousry, C., P. M. Zikry, H. M. Salem, E. B. Basalious, and O. N. El-Gazayerly, "Integrated nanovesicular/self-nanoemulsifying system (INV/SNES) for enhanced dual ocular drug delivery: statistical optimization, in vitro and in vivo evaluation.", Drug delivery and translational research, vol. 10, issue 3, pp. 801-814, 2020. Abstract

Ocular drug administration is usually problematic and suffers low bioavailability due to several physiological and biological factors that hinder their effective treatment. Terconazole (TZ) is considered as one of the effective ocular antifungal agents that is usually administrated intravitreally for higher efficacy. The aim of the work in this study is to formulate a TZ-loaded ocular drug delivery system with high efficiency and good tolerability. First, TZ-loaded bile-based nanovesicles (BBNV) were prepared and the formulation variables (namely, Span 60, cholesterol, and sodium deoxycholate levels) were optimized based on the results of the entrapment efficiency (EE%), particle size (PS), and zeta potential (ZP) using Box-Behnken statistical design. The optimized system was formulated using 73.59 mg Span 60, 1.28 mg cholesterol, and 3.11 mg sodium deoxycholate. The formulated system showed vesicles with PS of 526 nm, - 42.2 mV ZP, and 93.86% EE%. TZ release, cellular uptake, and cytotoxicity of the optimized system were evaluated in vitro. In addition, in vivo assessment of its safety was conducted histopathologically and via ocular irritation test to ensure the ocular tolerance of the system. Afterwards, the optimized TZ-loaded BBNV was integrated into a self-nanoemulsifying system (SNES) to allow faster TZ release for immediate antifungal effect, enhanced ocular residence, and improved ocular permeation. TZ release study revealed more than 2 folds increment in drug release rate from the integrated system compared to BBNV alone. Finally, this integrated system was assessed for its antifungal activity in vivo where it demonstrated higher antifungal activity against induced Candida albicans infection. Graphical abstract.

Salem, L. H., G. S. El-Feky, R. H. Fahmy, O. N. Elgazayerly, and A. A. Elbary, "Coated Lipidic Nanoparticles as a New Strategy for Enhancing Nose-to-Brain Delivery of a Hydrophilic Drug Molecule.", Journal of pharmaceutical sciences, vol. 109, issue 7, pp. 2237-2251, 2020. Abstract

Oral Almotriptan maleate (ALM) is used in the treatment of migraine; however, due to its extreme aqueous solubility, shows poor penetration and lesser concentration in the brain thus requiring frequent oral dosing. Being flexible and lipophilic in nature, nanostructured lipid carriers (NLCs) represent a promising tool in delivering therapeutic substances to the brain. This investigation is meant to explore the capability of mucoadhesive chitosan-coated NLCs to efficiently deliver ALM to the brain through the nasal route as a non-invasive alternative route for targeting the central nervous system (CNS). D-optimal design was adopted and thirteen different formulae were prepared using hot homogenization and ultrasonication technique; where an accurate amount of the almotriptan was added to the molten lipid mixture followed by the addition of the heated aqueous phase under stirring, then the mixture was subjected to homogenization and ultrasonication. The prepared systems were then assessed for their particle size, PDI (polydispersity index), zeta potential (ZP), and entrapment efficiency (EE). The optimized selected formula; F1; composed of 50/50 Compritol/Labrafil and a co-mixture of 2:1 tween 80: Lauroglycol all coated in chitosan, showed a PS of 255 nm, PDI 0.27, ZP 34.1 mV, and 80% EE. A bi-phasic in vitro drug release pattern was obtained, enhanced mucoadhesive property and ex-vivo permeability through sheep nasal mucosa were attained. The In vivo studies performed on albino rabbits showed significantly higher C results in plasma of the optimized ALM-NLC (1.54 μg/mL) compared to those of IN ALM solution (0.25 μg/mL) and ALM oral tablet market product (0.58 μg/mL). Brain C were found to be 3.64 μg/mL, 0.5 μg/mL and 0.48 μg/mL for IN ALM-NLC, oral ALM market product and, IN ALM solution, respectively. Histopathological examination marked the formula as safe.

Yousry, C., P. M. Zikry, E. B. Basalious, and O. N. El-Gazayerly, "Self-nanoemulsifying System Optimization for Higher Terconazole Solubilization and Non-Irritant Ocular Administration.", Advanced pharmaceutical bulletin, vol. 10, issue 3, pp. 389-398, 2020. Abstract

Eye drops' formulations of poorly water-soluble drugs, offer the advantage of crossing the lipophilic cornea, but their limited aqueous solubility may lead to low ocular bioavailability limiting their therapeutic uses. Terconazole (TZ) is an antifungal drug with low aqueous solubility, restricting its application in ocular fungal infection. Thus, the aim of the work in this study is to enhance TZ solubilization, permitting better ocular permeation and higher bioavailability. To achieve this goal, different self-nanoemulsifying systems (SNESs) were prepared using different oils, surfactants and co-surfactants. Ternary phase diagrams were constructed to identify self nano-emulsification regions for each oil system examined; either Labrafil M2125CS or Capryol 90. TZ saturated solubility in the different formulated systems were measured and systems showing highest potential for TZ solubilization were selected. The optimized systems were chosen based on their globule size, polydispersity index, self-emulsification characteristics. Finally, TZ release as well as the irritation effect via Hen's Egg test-chorioallantoic membrane (HET-CAM test) of the optimized system was observed in vitro. The optimized system was formulated using 20% w/w Labrafil M2125 CS, 50% w/w Tween 80 and 30% w/w Transcutol HP. Oil globules showed size range of 15.13 nm and self-emulsification time of 12.80 seconds. The system released 100% of the drug within half an hour compared to 2 hours in case of TZ-suspension. Finally, HET-CAM test showed non-irritating response and normal vascularization of the chorioallantoic membrane. The formulated SNES could be a promising approach to enhance ocular efficacy of TZ.

Gazayerly, O. E. N., I. Elsayed, R. M. El-Dahmy, A. H. Elshafeey, and N. A. A. E. Gawad, "Tripling the Bioavailability of Rosuvastatin Calcium Through Development and Optimization of an In-Situ Forming Nanovesicular System", Pharmaceutics, vol. 11, issue 6, pp. 1-18, 2019.
Ali, M., A. A. Motaal, M. A. Ahmed, A. Alsayari, and O. N. El-Gazayerly, "An in vivo study of Hypericum perforatum in a niosomal topical drug delivery system", Drug delivery, vol. 25, issue 1, pp. 417-425, 2018. hypericum_paper.pdf