Biomedical subjects

Mohamed A F Elmosallamy

Publications and source records attributed to Mohamed A F Elmosallamy.

4 recordsLinked to original sources

PubMed2005

Iron(II)-phthalocyanine as a novel recognition sensor for selective potentiometric determination of diclofenac and warfarin drugs.

Construction and characterization of potentiometric membrane sensors for quantification of diclofenac and warfarin drugs are described. The membranes of the sensors incorporate 1.8 wt.% iron(II)-phthalocyanine (Pc) as a molecular recognition reagent, 64.3 wt.% dibutylsebacate (DBS) solvent mediator, 1.8 wt.% tridodecylmethylammonium chloride (TDMAC) as membrane additive and 32.1 wt.% poly(vinyl chloride) (PVC) as a matrix. The sensors display linear response for 1 x 10(-2) to 9 x 10(-6) mol l(-1) (detection limit 5.4 x 10(-6) mol l(-1)) and 1 x 10(-2) to 5 x 10(-6) mol l(-1) (detection limit 3 x 10(-6) mol l(-1)) with anionic slopes of -61 +/- 1 and -63 +/- 1 mVdecade(-1) over the pH range 5.5-9 for declofenac and warfarin, respectively. Validation of the assay methods according to the quality assurance standards confirms their suitability for quality control purposes. Use of the sensor for the assay of various formulations of the drugs shows a mean average recovery of 99.7% of the nominal values and a mean precision of +/-0.3%. Significantly improved accuracy, precision, response time, stability, selectivity and sensitivity are offered by these simple and cost-effective potentiometric sensors compared with other standard techniques.

Calibration↗

PubMed2004

New highly selective picrate sensors based on charge-transfer complexes.

Two novel highly selective potentiometric membrane sensors responsive to picrate ion were developed. They are based on the use of N,N'-dibenzoyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (DD18C6)-picrate and Kryptofix 222-picrate charge-transfer complexes as novel electroactive materials in poly(vinyl chloride) matrix membranes plasticized with o-nitrophenyloctylether or dioctylphthalate. The sensors show a Nernstian response with anionic slopes of -59.0 +/- 0.1 and -58.0 +/- 0.2 mV decade(-1) over concentration ranges of 6.0 x 10(-5) - 1.0 x 10(-2) and 7.0 x 10(-5) - 1.0 x 10(-2) mol l(-1) picrate ion and pH ranges of 5-11.5 and 5.5-11.5 for DD18C6 and Kryptofix 222 based picrate sensors, respectively. Both sensors show highly selectivity towards picrate ion over many hydrophilic and lipophilic anions, and exhibit a non-Hofmeister selectivity sequence, which is an improvement over methods reported so far. The sensors are used for the titrimetric determination of alkaloids using picrate as a titrant.

Journal Article↗

PubMed2003

Novel ibuprofen potentiometric membrane sensors based on tetraphenylporphyrinato indium(III).

Two novel potentiometric membrane sensors responsive to the ibuprofen drug have been developed. These incorporate poly(vinyl chloride) and polyurethane matrix membranes containing 5,10,15,20-tetraphenylporphrinato (TPP) indium(II) ionophore plasticized with dibutylsebacate. The sensors show a near-Nernstian response with anionic slopes of -53 and -55 mV decade(-1), over the concentration range of 4.2 x 10(-6)-1.0 x 10(-2) and 3.3 x 10(-6)-1.0 x 10(-2) M ibuprofen within pH ranges of 4-9 and 5-9 for PVC and PU matrix membranes, respectively. A sensor based on a polyurethane membrane displays a lower detection limit and a wider linear working range, and a sensor based on a PVC membrane exhibits a better overall selectivity, especially in the presence of lipophilic organic anions. Both sensors are used for the quantification and quality-control assessment of ibuprofen in pharmaceutical preparations. The average recoveries are 99.1+/-0.3% and 99.3+/-0.3% for TPP In(III)-PVC and TPP In(III)-PU based membrane sensors, respectively. High selectivities towards ibuprofen in the presence of many anions, drug excipients and diluents are offered by both sensors, which exhibit a non-Hofmeister selectivity pattern.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2002

LC and TLC determination of cinnarizine in pharmaceutical preparations and serum.

New high performance liquid chromatography (HPLC) and thin layer densitometry (TLC) methods are developed for quantification of cinnarizine in dosage forms in the presence of its photo-degradation products and related substances and in the presence of its metabolites in serum. Mobile phases consisting of benzene-methanol-formic acid (80:17:3) and methanol-acetate buffer of pH 4 (70:30) are satisfactorily used for resolution of cinnarizine from associated substances by TLC and HPLC techniques, respectively. The lower detection limits are 16 and 10 ng microl(-1) of cinnarizine with standard deviations of 1.3 and 1.1% with TLC and HPLC, respectively. The methods are used for assessment of drug purity, stability, bioavailability, bioequivalency and tablet dissolution rate. Four cinnarizine related substances and six drug degradation products are isolated and identified by infrared and mass spectrometry. The results obtained by both techniques are in good agreement and offer the advantages of reproducibility and accuracy.

Animals↗