Publications by authors named "Ashgan F Mahmoud"

2 Publications

  • Page 1 of 1

Formulation of chitosan coated nanoliposomes for the oral delivery of colistin sulfate: characterization, Tc-radiolabeling and biodistribution studies.

Drug Dev Ind Pharm 2021 Apr 9:1-10. Epub 2021 Apr 9.

Labeled Compounds Department, Hot Lab Center, Egyptian Atomic Energy Authority, Cairo, Egypt.

Colistin sulfate is a very important antibiotic for the treatment of multidrug-resistant Gram-negative infections. Unfortunately, it has low oral bioavailability and several side effects following parenteral administration. The present study aims to develop chitosan-coated colistin nanoliposomes to improve the stability in the gastrointestinal tract and to enhance the oral delivery of colistin. The chitosan-coated colistin nanoliposomes were obtained via thin-film evaporation and electrostatic deposition methods using either Span 60, Tween 65 or Tween 80 as surfactants with different cholesterol: surfactant: soya lecithin ratios. The influence of systems variables was further characterized by vesicle size analysis, zeta potential (ZP), poly dispersibility index (PDI), and also their entrapment efficiency percentage (EE %) was evaluated. Various systems were formed with vesicle sizes in the nano-range, 155.64 ± 12.53 nm to 315.64 ± 15.90 nm, and EE % of 45.2 ± 2.9% to 81.8 ± 2.9%. Moreover, the ZP value of the prepared nanoliposomes switched from a negative to a positive value after chitosan coating. To track the released colistin technetium 99m (Tc) was incorporated into the optimum system (S-3) system via direct coupling with colistin. Chitosan-coated Tc-colistin nanoliposome, Tc-colistin suspension, and Tc-chitosan-coated nanoliposomes (placebo) were administered orally into bacterial infection () bearing mice. The biodistribution results showed that chitosan-coated nanoliposome significantly enhanced the bioavailability of colistin compared to colistin suspension (the commercially available). Moreover, the system effectively improved the localization of colistin at the infected muscle. In conclusion, this approach offers a promising tool for enhanced oral delivery of colistin.
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http://dx.doi.org/10.1080/03639045.2021.1908334DOI Listing
April 2021

Radioiodination and in vivo assessment of the potential of newly synthesized pyrrolizine-5-carboxamides derivative in tumor model.

Appl Radiat Isot 2020 Dec 8;166:109369. Epub 2020 Aug 8.

Labeled Compounds Dept. Hot Labs Center, Atomic Energy Authority, Cairo, Egypt; Faculty of Pharmacy, Albayan University, Baghdad, Iraq.

Recently, pyrrolizine derivatives have been reported to possess numerous anticancer activities. In a previous study, (EZ)-6-((4-chlorobenzylidene)-amino)-7-cyano-N-(p-tolyl)-2,3-dihydro-1H-pyrrolizine carboxamide (EZPCA) compound was synthesized and the cytotoxic activity of EZPCA toward COX-2 enzyme (overexpressed in cancer cells) was reported. In order to assess the suitability of this compound as a promising pilot structure for in vivo applications, EZPCA was radiolabeled with radioiodine-131 (I) and various factors affecting radiolabeling process were studied. Quality control studies of [I]iodo-EZPCA were performed using paper chromatography and HPLC was used as a co-chromatographic technique for confirming the radiochemical yield. Biodistribution studies of [I]iodo-EZPCA were undertaken in normal and tumor bearing mice. The radiochemical yield percentage of [I]iodo-EZPCA was 94.20 ± 0.12%. The biodistribution results showed evident tumor uptake of [I]iodo-EZPCA with promising target/non-target (T/NT) ratios. As a conclusion, these data suggest that [I]iodo-EZPCA had high binding efficiency, high tumor uptake and sufficient stability to be used be used in diagnostic studies.
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http://dx.doi.org/10.1016/j.apradiso.2020.109369DOI Listing
December 2020