Browsing by Author "Al-Mahallawi, Abdulaziz M"

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    Enhancing Tumor Targeting Efficiency of Radiolabeled Uridine (Via) Incorporation Into Nanocubosomal Dispersions
    (NCBI, 2020-02) Sayed, Manal M; El-Sabagh, Hanan A; Al-Mahallawi, Abdulaziz M; Abd El-Halim, El-Sayed; Amin, Abeer M; AbdEl-Bary, Ahmed
    Background: Several nanosystems are currently being utilized to enhance the targeting efficiency of several cancer chemotherapeutic agents. This study was designed to improve tumor accumulation of iodine-125 (125I)-uridine via incorporation into a nanocubosomal preparation. Materials and Methods: Nanocubosomes were prepared with the aid of Glycerol mono-oleate and Pluronic F127. Each prepared nanocubosomal preparation was adequately characterized by testing their particle size, polydispersity index (PDI), zeta potential (ZP), and transmission electron microscopy. The radiolabeling of uridine with 125I was attempted using several oxidizing agents to achieve a high radiochemical yield, and the factors affecting the reaction yield were studied in detail. A comparative biodistribution study of free 125I-uridine and 125I-uridine loaded nanocubosomes was performed in normal and tumor bearing mice. The biodistribution was evaluated by intravenous injection of the sterile test solution, and animals were anesthetized and dissected at different time intervals postinjection (p.i.). Results: 125I-uridine was obtained in a high radiochemical yield (92.5% ± 0.8%). Afterward, 125I uridine was incorporated in a selected nanocubosome formulation, which showed nanosized cubic particles (178.6 ± 0.90 nm) with PDI (0.301 ± 0.04) and a ZP (34.35 ± 0.4). The biodistribution studies revealed that 125I-uridine nanocubosomes showed higher tumor localization (3.1 ± 0.4%IA/g at 2 h p.i. and a tumor/muscle ratio of 6.2) compared with the free 125I-uridine (2.7% ± 0.4%IA/g at 2 h p.i. and a tumor/muscle ratio of 3.3). Conclusion: The results of this study confirmed that 125I-uridine loaded nanocubosome had better efficiency in targeting the tumor site, which makes it an adequate targeting agent for tumor imaging.
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    Vilazodone-phospholipid mixed micelles for enhancing oral bioavailability and reducing pharmacokinetic variability between fed and fasted states
    (Elsevier, 2022-09-25) El Said, Hala S; Lalatsa, Aikaterini; Al-Mahallawi, Abdulaziz M; El Leithy, Eman Saddar; Ghorab, Dalia M
    Despite the effectiveness and high tolerability of vilazodone (VLZ) as an antidepressant, its use is still limited due to its poor solubility and food dependent absorption. This study aims to load VLZ-phospholipid complex into self- assembled micelles forming VLZ-PL mixed micelles (VLZ-PL-MM), that can enhance VLZ solubility, improve its bioavailability and reduce the pharmacokinetic variability between the fed and fasting conditions. The effect of surfactant type and concentration was assessed using four different non-ionic surfactants (Brij 58, Tween 80, Labrasol and Pluronic F127) in four different weight ratios between the drug-complex and surfactant (1:0.5, 1:1, 1:2 and 1:3 w/w). Two VLZ-PL-MM formulae prepared using Brij 58 and Labrasol in 1:3 w/w ratio were selected as optimised ones since they have the highest encapsulation efficiency (100.83 and 93.87%, respectively), a particle size below 250 nm (206.73 and 221.33 nm, respectively) and negative zeta potential values (− 29.63, − 17.20 mV, respectively). Lyophilisation of these formulations using 3% sucrose was successful with no sta- tistical changes in particle size and zeta potential upon rehydration. Both formulations elicited faster and higher in-vitro drug release profiles compared to the pure drug and the marketed tablet. In addition, both selected formulae improved ex-vivo permeation across rabbit intestinal membrane compared to the pure drug and the marketed tablet, with marked superiority of the one prepared using Brij 58. The results of the in-vivo study in male albino rabbits revealed similar AUC0-24 values after the oral administration of the best achieved VLZ-PL-MM system under fed and fasted conditions (769.89 and 741.55 ng.h mL− 1 , respectively). On the other hand, the marketed product showed significantly lower values of the AUC0-24 relative to the VLZ-PL-MM system and there was a marked enhancement of absorption of drug from the marketed product in presence of food (244.24 and 174.96 ng.h mL− 1 under fed and fasted conditions, respectively). In addition, VLZ concentrations in the brain after 24 h obtained from the selected VLZ-PL-MM were significantly higher than those obtained from marketed tablet under fed and fasted conditions. Thus, the phospholipid mixed micelles formulation enhances the oral bioavailability of the poorly soluble drug and reduces the pharmacokinetic variability between fasting and fed conditions