Browsing by Author "Elkheshen S.A."

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    Nanoparticles as tool for enhanced ophthalmic delivery of vancomycin: a multidistrict-based microbiological study, solid lipid nanoparticles formulation and evaluation
    (Taylor and Francis Ltd., 2016) Yousry C.; Fahmy R.H.; Essam T.; El-laithy H.M.; Elkheshen S.A.; Department of Pharmaceutics and Industrial Pharmacy; Faculty of Pharmacy; Cairo University; Kasr El-Aini St; Cairo; Egypt; Department of Microbiology and Immunology; and Biotechnology Center; Faculty of Pharmacy; Cairo University; Kasr El-Aini St; Cairo; Egypt; Department of Pharmaceutics and Industrial Pharmacy; Faculty of Pharmacy; October University for Modern Sciences and Arts; Cairo; Egypt; Department of Pharmaceutical Technology; Faculty of Pharmaceutical Sciences and Pharmaceutical Industries; Future University in Egypt; Cairo; Egypt
    Context: A microbiological multidistrict-based survey from different Egyptian governorates was conducted to determine the most prevalent causative agents of ocular infections in the Egyptian population. Antibiotic sensitivity testing was then performed to identify the most potent antimicrobial agent. Vancomycin (VCM) proved the highest activity against gram-positive Staphylococcus bacteria, which are the most commonly isolated causative agents of ocular infection. However, topically applied VCM suffers from poor ocular bioavailability because of its high molecular weight and hydrophilicity. Objective: The aim of the present study was to develop VCM-loaded solid lipid nanoparticles (SLNs) using water-in-oil-in-water (W/O/W) double emulsion, solvent evaporation technique to enhance ocular penetration and prolong ophthalmic residence of VCM. Method: Two consecutive full factorial designs (24 followed by 32) were adopted to study the effect of different formulation and process parameters on SLN formulation. The lipid type and structure, polyvinyl alcohol (PVA) molecular weight and concentration, sonication time, as well as lipid:drug ratio were studied as independent variables. The formulated SLN formulae were evaluated for encapsulation efficiency (EE%), particle size (PS), and zeta potential as dependent variables. Results: The statistically-optimized SLN formula (1:1 ratio of glyceryltripalmitate:VCM with 1% low molecular weight PVA and 1 min sonication time) had average PS of 277.25 nm, zeta potential of ?20.45, and 19.99% drug encapsulation. Scanning and transmission electron micrographs showed well-defined, spherical, homogenously distributed particles. Conclusion: The present study suggests that VCM incorporation into SLNs is successfully achievable; however, further studies with different nanoencapsulation materials and techniques would be valuable for improving VCM encapsulation. � 2016 Informa UK Limited, trading as Taylor & Francis Group.
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    Studying the influence of formulation and process variables on Vancomycin-loaded polymeric nanoparticles as potential carrier for enhanced ophthalmic delivery
    (Elsevier B.V., 2017) Yousry C.; Elkheshen S.A.; El-laithy H.M.; Essam T.; Fahmy R.H.; Department of Pharmaceutics and Industrial Pharmacy; Faculty of Pharmacy; Cairo University; Kasr El-Aini St; Cairo; Egypt; Department of Pharmaceutics and Pharmaceutical Technology; Faculty of Pharmaceutical Sciences and Pharmaceutical Industries; Future University in Egypt; Cairo; Egypt; Department of Pharmaceutics and Industrial Pharmacy; Faculty of Pharmacy; University of Modern Science and Art; Cairo; Egypt; Department of Microbiology and Immunology; Faculty of Pharmacy; Cairo University; Kasr El-Aini St; Cairo; Egypt; Department of Pharmaceutics; Faculty of Pharmacy; Ahram Canadian University; 6th of October City; Cairo; Egypt
    Ocular topically applied Vancomycin (VCM) suffers poor bioavailability due to its high molecular weight and hydrophilicity. In the present investigation, VCM-loaded polymeric nanoparticles (PNPs) were developed aiming to enhance its ocular bioavailability through prolonging its release pattern and ophthalmic residence. PNPs were prepared utilizing double emulsion (W/O/O), solvent evaporation technique. 23 � 41 full factorial design was applied to evaluate individual and combined influences of polymer type, Eudragit� RS100, sonication time, and Span�80 concentration on PNPs particle size, encapsulation efficiency, and zeta potential. Further, the optimized formulae were incorporated in 1% Carbopol�-based gel. In-vivo evaluation of the optimized formulae was performed via Draize test followed by microbiological susceptibility testing on albino rabbits. Results revealed successful formulation of VCM-loaded PNPs was achieved with particle sizes reaching 155 nm and up to 88% encapsulation. Draize test confirmed the optimized formulae as non-irritating and safe for ophthalmic administration. Microbiological susceptibility testing confirmed prolonged residence, higher Cmax. with more than two folds increment in the AUC(0.25�24) of VCM-PNPs over control groups. Thus, VCM-loaded PNPs represent promising carriers with superior achievements for enhanced Vancomycin ophthalmic delivery over the traditional use of commercially available VCM parenteral powder after constitution into a solution by the ophthalmologists. � 2017 Elsevier B.V.