King Faisal Specialist Hospital & Research Centre

About: King Faisal Specialist Hospital & Research Centre is a healthcare organization based out in Riyadh, Saudi Arabia. It is known for research contribution in the topics: Detection limit & High-performance liquid chromatography. The organization has 58 authors who have published 157 publications receiving 3527 citations.

Determination of pravastatin in tablets by capillary electrophoresis

Abstract: Pravastatin (PRA) is an inhibitor of HMG-CoA reductase enzyme, which is clinically used as a hypolipidemic agent to reduce cholesterol level. A capillary electrophoretic method for the determination of PRA in pharmaceutical tablet formulations is described. PRA and lansoprazole as an internal standard (IS) were well migrated in the background electrolyte of 10 mM borate buffer (pH 8.5) and 10% acetonitrile using a fused silica capillary. The separation was achieved by applying 27.5 kV, detecting at 200 nm and injecting the sample for 0.5 s and with an average migration time (tm) for PRA and IS of 4.7 and 3.9 min, respectively, at ambient temperature. The results were precise and repeatable for areas of the peaks and peak normalization ratio (PNPRA/PNIS). Linearity was found in the concentration range of 1.56-7.78 x 10(-5) M. Intra-day and Inter-day assays were performed and reliable results were obtained. Limit of detection and limit of quantitation were 8 x 10(-6) and 2.4 x 10(-5) M, respectively. The proposed method was successfully applied for the analysis of PRA in the pharmaceutical tablet formulation. The method proved simple, precise and fast since the analysis can be performed in less than 5 min.

Voltammetric Investigation and Determination of Mefloquine

Abstract: The electrochemical reduction behavior of mefloquine HCl (MEF), the antimalarial drug, was studied in aqueous alcoholic media at a hanging mercury drop electrode. Cyclic voltammetric studies showed one well-defined reduction peak and one ill-defined reduction wave between pH 1.5 and 12.03. The reduction was found as irreversible or quasireversible depending on pH and exhibited diffusion controlled process. The mechanism of reduction process was discussed. A systematic study of the experimental parameters that affect the differential pulse and square wave response was carried out and the optimized experimental conditions were obtained. The calibration plots were derived for the determination of MEF in pharmaceutical dosage forms and biological samples. DPV and SWV techniques for the determination of MEF in Britton–Robinson buffer at pH 11.10, which allows quantitation over the 6×10−6 to 8×10−5 M range in the supporting electrolyte, were proposed. The linear response was obtained in samples in the ranges of 6×10−6 to 6×10−5 M for both techniques. These methods are fully validated. The standard addition method was used in the biological media. No electroactive interferences from the excipients and endogenous substances were found in tablets and biological fluids.

Thin layer chromatographic resolution of some 2‐arylpropionic acid enantiomers using L‐(−)‐serine, L‐(−)‐threonine and a mixture of L‐(−)‐serine and L‐(−)‐threonine‐impregnated silica gel as stationary phases

Abstract: Impregnated silica TLC plates with L-(−)-serine and L-(−)-threonine and a mixture of L-(−)-serine and L-(−)-threonine (1:1) as chiral selectors were prepared to use as chiral stationary phases (CSPs) in thin layer chromatography. The resolution of the enantiomers of 2-arylpropionic drugs, including ibuprofen, ibuproxam, ketoprofen, pranoprofen, benoxaprofen, flurbiprofen and tiaprofenic acid was investigated on these CSPs. A mobile phase system of acetonitrile–methanol–water (16:4:0.5, v/v/v) was used. The spots were detected with iodine vapours and the detection limits were found to range between 0.25 and 0.5 µg/mL for all racemic compounds investigated. The effect of temperature, pH and concentration of the impregnating chiral selectors on resolution has been studied. Copyright © 2003 John Wiley & Sons, Ltd.

Infectious diarrhea. Managing a misery that is still worldwide.

Abstract: Infectious diarrhea is the largest single cause of morbidity and mortality in the world. Bacteria, viruses, and protozoan parasites are the most common causative agents. Treatment in most cases of bacterial and viral diseases consists of correcting fluid loss and electrolyte imbalance by oral or parenteral rehydration. Antimicrobial therapy is reserved for very ill patients only. With the exception of Cryptosporidium, for which no effective agent is yet available, all protozoan infections are treatable with metronidazole.

On-line monitoring of r-captopril using an amperometric biosensor/sequential injection analysis system

Abstract: An automated system for the on-line monitoring of R-captopril, based on the concept of sequential injection analysis with an amperometric biosensor (based on D-amino acid oxidase) as detector, is described. The sampling rate is 80 samples per hour with an RSD <0.22% in the linear range between 0.2 and 1.0 μmol/L. The detection limit is 160 nmol/L.