Ahmed Elshafeey

Pluronic-based nanostructured gels were developed and optimized to increase the permeability of vinpocetine through the skin and the mucous layer of the nasal cavity. A modified thin-film hydration technique was utilized to prepare the nanostructured gel formulae containing different concentrations of Pluronic F127, Pluronic F68 and oleic acid. The formed nanodispersions were tested for their pH, particle size, zeta potential, polydispersity index, entrapment efficiency and gelation temperature. Box-Behnken statistical design was used to choose the optimized nasal and transdermal nanostructured gel formulae utilizing Design-Expert® software. The nasal optimized formula consisted of 2.4% oleic acid, 23.46% total surfactants and 27.13% Pluronic F68, had a gelation temperature of 35 °C which could be suitable to form in situ gel upon application into the nasal cavity. On the other hand, the transdermal optimized formula, composed of 1.77% oleic acid, 22.46% total surfactants and 11.54% Pluronic F68, formed gel at room temperature that could be suitable to be applied onto the skin. The optimized gel formulae were investigated for their in vitro drug release, rheology, morphology, histopathology and ex vivo permeation. The extent of drug permeated from the optimized formula through both nasal and skin membranes was significantly increased by 3.39 and 4.7 folds when compared to the drug suspension. Finally, the obtained findings ensured the creditable impact of the nanostructured gels as promising nanocarriers for enhancing transmucosal and transdermal vinpocetine permeation.

A series of second-generation analogues for 2-(1-(2-(4-butylphenyl)-4-methylthiazol-5-yl)ethylidene)aminoguanidine (1) have been synthesized and tested against methicillin-resistant Staphylococcus aureus (MRSA). The compounds were designed with the objective of improving pharmacokinetic properties. This main aim has been accomplished by replacing the rapidly hydrolyzable Schiff-base moiety of first-generation members with a cyclic, unhydrolyzable pyrimidine ring. The hydrazide-containing analogue 17 was identified as the most potent analogue constructed thus far. The corresponding amine 8 was 8 times less active. Finally, incorporating the nitrogenous side chain within an aromatic system completely abolished the antibacterial character. Replacement of the n-butyl group with cyclic bioisosteres revealed cyclohexenyl analogue 29, which showed significant improvement in in vitro anti-MRSA potency. Increasing or decreasing the ring size deteriorated the antibacterial activity. Compound 17 demonstrated a superior in vitro and in vivo pharmacokinetic profile, providing compelling evidence that this particular analogue is a good drug candidate worthy of further analysis.

Background: Olanzapine is a psychotropic agent that belongs to the thienobenzodiazepine class. Objective: The aim of this study was to assess the bioequivalence of 2 commercial 10-mg tablet formulations of olanzapine by statistical analysis of the pharmacokinetic parameters Cmax, AUC from 0 to 72 hours after dosing (AUC0-72), and AUC0-∞ as required by the Egyptian health authority for the marketing of a generic product. Methods: This bioequivalence study was carried out in healthy male volunteers using a single-dose, randomized, 2-way crossover design under fasting conditions. Statistical analysis of the pharmacokinetic parameters Cmax, AUC0-72, and AUC0-∞ was conducted to determine bioequivalence (after log-transformation of data using analysis of variance and 90% CIs) and to gain marketing approval in Egypt. The formulations were considered to be bioequivalent if the log-transformed ratios of the 3 pharmacokinetic parameters were within the predetermined bioequivalence range (ie, 80%-125%), as established by the US Food and Drug Administration (FDA). Both the test product (Trademark: Integrol® [Global Napi Pharmaceuticals, Cairo, Egypt]) and the reference product (Trademark: Zyprexa® [Eli Lilly and Company, Basingstoke, Hampshire, United Kingdom]) were administered as 10-mg tablets with 240 mL of water after an overnight fast on 2 treatment days, separated by a 2-week washout period. After dosing, serial blood samples were collected for 72 hours. Plasma samples were analyzed using a sensitive, reproducible, and accurate liquid chromatography-tandem mass spectrometry method capable of quantitating olanzapine in the range of 0.167 to 16.7 ng/mL, with a lower limit of quantitation of 0.167 ng/mL. Adverse events were reported by the volunteers as instructed or observed by the resident physician, and were recorded, tabulated, and evaluated. Results: Twenty-four healthy adult male volunteers participated in this study. Their mean (SD) age was 24.7 (6.2) years (range, 19-41 years), mean weight was 73.4 (6.7) kg (range, 64-89 kg), and mean height was 174.25 (4.6) cm (range, 168-186 cm). Values for Cmax, AUC0-72, AUC0-∞, Tmax, t1/2, and the terminal disposition rate constant were found to be in agreement with previously reported values. The differences between the 2 products did not reach statistical significance at P ≤ 0.05 (90% CIs: Cmax, 101.82-124.79; AUC0-72, 93.36-102.04; and AUC0-∞, 88.57-101.77). The test/reference ratio of these parameters was within the acceptance range of the FDA criterion for bioequivalence. Both formulations were apparently well absorbed from the gastrointestinal tract (ie, no specific gastrointestinal tract-related adverse events were reported). Conclusions: In this small study in healthy male volunteers, there were no statistically significant differences in any of the calculated pharmacokinetic parameters between the 10-mg test and reference tablets of olanzapine. The 90% CIs for the ratios of mean Cmax, AUC0-72, and AUC0-∞ were within the range of 80% to 125% (using log-transformed data), meeting the FDA regulatory criterion for bioequivalence. Both formulations were well tolerated. © 2009 Excerpta Medica Inc. All rights reserved.