Sayed H. Auda

Preparation, physicochemical characterization and biological evaluation of cefodizime metal ion complexes

Objectives Cefodizime is a broad spectrum cephalosporin belonging to the third generation agents. In this study, attention has been paid to the preparation, physicochemical characterization and biological evaluation of new Cu2+, Zn2+, Fe3+, Co2+ and Al3+ complexes of cefodizime.

Characterization of the interaction of cefadroxil with different metal ions using CE.

The present study describes the application of CE to investigate the interaction between a cephalosporin, cefadroxil and different metal ions. This study aims at quantifying the interaction of cefadroxil with Zn2+, Al3+, Fe3+, Cu2+ and Co2+ ions using the effective electrophoretic mobility as a parameter for calculation of the reaction association constant (K). For this purpose, the electrophoretic mobilities of cefadroxil at different metal ion concentrations in citrate buffer pH 3.6 were determined. A mathematical model to calculate the association constant between cefadroxil and metal ions was used. The results showed that a strong change in the cefadroxil electrophoretic mobility was observed by increasing the metal ion concentrations. The results revealed that by increasing the concentration of metal ions in the running buffer the degree of complexation increases too. On the basis of the results, the strength of the interaction of cefadroxil with the investigated metal ions follows the order Zn2+>Cu2+>Co2+>Fe3+>Al3+. The association constant of the investigated reactions ranged from 451.57 to 1546.52 L/mmol. The results indicate that it is possible to characterize the interaction between cefadroxil and metal ions quantitatively using CE.

Nimesulide/Methyl β‐Cyclodextrin Inclusion Complexes: Physicochemical Characterization, Solubility, Dissolution, and Biological Studies

Preclinical Research

Effect of Different Metal Ions on the Biological Properties of Cefadroxil

The effect of different metal ions on the intestinal transport and the antibacterial activity of cefadroxil [(6R,7R)-7-{[(2R)-2-amino-2-(4-hydroxyphenyl)acetyl]amino}-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid] was investigated. The [14C]Gly-Sar uptake via PEPT1 was inhibited by Zn2+ and Cu2+ treatment in a concentration-dependent manner (Ki values 107 ± 23 and 19 ± 5 µM, respectively). Kinetic analysis showed that the Kt of Gly-Sar uptake was increased 2-fold in the presence of zinc sulphate (150 µM) whereas the Vmax value were not affected suggesting that zinc ions inhibited Gly-Sar uptake by PEPT1 in a competitively manner. Ni2+ exhibited moderate inhibitory effect, whereas Co2+, Mg2+, Al3+ ions showed no inhibitory effect on Gly-Sar uptake via PEPT1. Subsequently, we examined the effect of Zn2+ and Al3+ ions on the transepithelial transport of cefadroxil across Caco-2 cells cultured on permeable supports. The results showed that zinc ions inhibited the transepithelial flux of cefadroxil at Caco-2 cell monolayers while Al3+ ions had no effect. The interaction of cephalosporins with the metal ions could suggest negative effects of some metal ions on the clinical aspects of small intestinal peptide and drug transport. Finally, the effect of Zn2+, Cu2+ and Al3+ ions on the antibacterial activity of cefadroxil was tested. It was found that there is no significant difference between the activity of cefadroxil and the cefadroxil metal ion complexes studied against the investigated sensitive bacterial species.

Evaluation of wound healing activity of henna, pomegranate and myrrh herbal ointment blend

This study assessed the wound healing potential and antimicrobial activity of henna, pomegranate and myrrh extract formulations and their blend in excision, and dead space wound models in rats in comparison to a marketed ointment (gentamycin). The natural extracts were used in ointment formulations alone or in a combination of three extracts at a total concentration of 15% w/w in medications. The percent of wound contraction in case of henna, myrrh, pomegranate, the blend and gentamycin (10 mg/kg) were 85.90–98.5%, 88.35–99.52%, 93.55–100%, 97.30–100%, and 90.25–100% from days 16 to 20, respectively. The blended formulation showed the highest increase in the percent of wound contraction and decrease in the epithelisation period compared to other formulations and showed comparable results to the standard ointment. The histological studies of excision biopsy at day 24 showed healed skin structures with normal epithelisation, the restoration of adnexa and fibrosis within the dermis in all of the formulation- and gentamycin-treated groups while the control group lagged behind in the formation of the amount of ground substance in the granulation tissue. The formulations showed antimicrobial activity against Candida, Staphylococcus aureus, mucous membrane infections and E. coli topical infections. The study proved the wound healing potential and antimicrobial activity of the herbal extract.

Novel chlorhexidine dermal patches, preparation characterization and antimicrobial evaluation

The purpose of this work is to develop chlorhexidine dermal patches using Eudragit® RL100 as the patch forming polymer. Solvent casting technique was employed in the preparation of the patches. The prepared patches, the corresponding physical mixtures, and the individual ingredients were physicochemically characterized by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) to investigate drug-excipient interactions. The results of the incompatibility studies indicated that the drug was molecularly distributed in Eudragit RL100 matrix. The developed patches were evaluated in terms of tensile strength, percentage of elongation, patch weight, surface pH, content uniformity, and drug dissolution profile. The developed chlorhexidine-medicated patches were flexible, transparent, homogenous, elegant, and smooth. Evaluation of the antimicrobial activity of the developed patches showed effective antimicrobial action against varieties of microorganisms.