omar elkadi

Objective: Alginate polymers suffer from rapid release of water soluble drugs in physiologic salt concentration. In this study, a new microsphere delivery system composed of GMO-cubosome embedded in Ca-alginate was designed to improve the release properties of a water-soluble model drug (Clindamycin). Methods: GMO-alginate based microspheres were prepared by w/o emulsion method, and formulation variables such as alginate molecular weight, concentration, surfactant ratio, and homogenization speed were fixed, while alginate:GMO ratio and drug concentration were investigated. Results: Alginate:GMO ratio significantly affected the particle size and morphology. Microparticles with low GMO contents (1:0.25) were spherical in shape with average diameter of 35.2 μm, with increasing GMO contents (1:0.5 to 1:1), microparticles become more flattened, collapsed and larger in size. Degradation study revealed that the erosion of microspheres decreased significantly by GMO-cubosomes addition as co...

Objective: Alginate polymers suffer from rapid release of water soluble drugs in physiologic salt concentration. In this study, a new microsphere delivery system composed of GMO-cubosome embedded in Ca-alginate was designed to improve the release properties of a water-soluble model drug (Clindamycin). Methods: GMO-alginate based microspheres were prepared by w/o emulsion method, and formulation variables such as alginate molecular weight, concentration, surfactant ratio, and homogenization speed were fixed, while alginate:GMO ratio and drug concentration were investigated. Results: Alginate:GMO ratio significantly affected the particle size and morphology. Microparticles with low GMO contents (1:0.25) were spherical in shape with average diameter of 35.2 μm, with increasing GMO contents (1:0.5 to 1:1), microparticles become more flattened, collapsed and larger in size. Degradation study revealed that the erosion of microspheres decreased significantly by GMO-cubosomes addition as compared to blank Ca-alginate microspheres. 50% weight loss was reached at approximately 8hrs for 1:0.25 GMO containing microspheres as compared to 5.5hrs for blank microspheres without cubosomes, indicating that the presence of cubosomes increased the stability of Ca-alginate microspheres. Additionally, the extent of Clindamycin release from the Alginate:GMO(1:0.25) microspheres was 47% lower than the release from the conventional microspheres. Conclusions: These novel microparticles have a uniform structure, confined size distribution, satisfactory entrapment efficiency, and acceptable sustained release properties.

Sodium Alginate(SA), Ethyl Cellulose(EC), and Eudragit RS100 are examples of polymers commonly used in gastroretentive dosage forms. The main objective of this study was to investigate the possible effect of these polymers on the in-vitro anti-H.pylori activity of a third generation fluoroquinolone antibacterial agent; Lomefloxacin hydrochloride (LFX). The in-vitro activity of free LFX and LFX-polymer blends (SA, EC, or RS100) were carried out against clinical isolates of H. pylori and the minimal inhibitory concentrations (MIC) were determined by agar dilution susceptibility method. To investigate the nature of polymer effect on drug activity; drug-polymer solid dispersions (blend films) were prepared by Solvent Casting technique and characterized by conventional techniques including DSC, XRD, FTIR analysis as well as by in-vitro drug release study in gastric environment. Experimental results observed showed that LFX has an in-vitro anti-H.pylori activity with MIC of 0.5 µg/ml and ...

The purpose of this study was to use near-infrared (NIR) transmission spectroscopic technique to determine clindamycin plasma concentration after oral administration of clindamycin loaded GMOalginate microspheres using rabbits as animal models. Lyophilized clindamycin–plasma standard samples at a concentration range of 0.001–10 mg/ml were prepared and analyzed by NIR and HPLC as a reference method. NIR calibration model was developed with partial least square (PLS) regression analysis. Then, a single dose in-vivo evaluation was carried out and clindamycin–plasma concentration was estimated by NIR. Over 24 h time period, the pharmacokinetic parameters of clindamycin were calculated for the clindamycin loaded GMO-alginate microspheres (F3) and alginate microspheres (F2), and compared with the plain drug (F1). PLS calibration model with 7-principal components (PC), and 8000–9200 cm
1 spectral range shows a good correlation between HPLC and NIR values with root mean square error of cross validation (RMSECV), root mean square error of prediction (RMSEP), and calibration coefficient (R2) values of 0.245, 1.164, and 0.9753, respectively, which suggests that NIR transmission
technique can be used for drug-plasma analysis without any extraction procedure. F3 microspheres exhibited controlled and prolonged absorption Tmax of 4.0 vs. 1.0 and 0.5 h; Cmax of 2.370.3 vs. 3. 810.8 and 5.430.7 mg/ml for F2 and F1, respectively. These results suggest that the combination of
GMO and alginate (1:4 w/w) could be successfully employed for once daily clindamycin microspheres
formulation which confirmed by low Cmax and high Tmax values.

Objective: Alginate polymers suffer from rapid release of water soluble drugs in physiologic salt concentration. In this study, a new microsphere delivery system composed of GMO cubosome embedded in Ca-alginate was designed to improve the release properties of a water-soluble model drug (Clindamycin). Methods: GMO-alginate based microspheres were prepared by w/o emulsion method, and formulation variables such as alginate molecular weight, concentration, surfactant ratio, and homogenization speed were fixed, while alginate:GMO ratio and drug concentration were investigated.
Results: Alginate:GMO ratio significantly affected the particle size and morphology. Microparticles with low GMO contents (1:0.25) were spherical in shape with average diameter of 35.2 μm, with increasing GMO contents (1:0.5 to 1:1), microparticles become more flattened, collapsed and larger in size. Degradation study revealed that the erosion of microspheres decreased significantly by GMO-cubosomes addition as compared to blank Ca-alginate microspheres. 50% weight loss was reached at approximately 8hrs for 1:0.25 GMO containing microspheres as compared to 5.5hrs for blank microspheres without cubosomes, indicating that the presence of cubosomes increased the stability of Ca-alginate microspheres. Additionally, the extent of Clindamycin release from the Alginate:GMO (1:0.25) microspheres was 47% lower than the release from the conventional microspheres.
Conclusions: These novel microparticles have a uniform structure, confined size distribution, satisfactory entrapment efficiency, and acceptable sustained release properties.

Microbial-based therapy of cancer is one of the earliest non-surgical anticancer therapies. The main limitation of such therapies is the toxicity of the therapeutic dose. This article discusses a novel approach that exploits cancer multidrug resistance (MDR) to provide a safer microbial-based therapy. As multidrug resistant cells can only contain limited amounts of a variety of susceptible drugs including certain antibiotics, we can take advantage of MDR to create a micro-environment (antibiotic free) that favors growth of intracellular bacteria within cancer cells. Thus, this approach targets cancer cells and spares normal cells (shielded by antibiotic): providing a more selective thus safer anticancer treatment. This article also explores the potentials of Chlamydia pneumoniae as an anti-cancer agent in this MDR-selective microbial-based therapy: its unique life cycle and the immune response to its infection suggest that it could be used directly, in the proposed approach, without any pre-requirements. Copyright © 2013 Elsevier Ltd. All rights reserved.