University of North Florida
Browse the Citations
-OR-

Contact Info

Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

View Stuart Chalk's profile on LinkedIn

Pharmaceutical

Classification: Pharmaceutical -> suppository

Citations 4

"Photochemical Derivatization And Spectrofluorimetric Determination Of Chlorpromazine By Flow Injection"
Anal. Chim. Acta 1992 Volume 256, Issue 1 Pages 105-111
J. Martínez Calatayud*, C. Gómez Benito

Abstract: Chlorpromazine hydrochloride (I) in 0.146 mM HCl solution was passed through a 300-cm PTFE tube helically coiled around a UV lamp in a continuous-flow manifold. The max. photo-oxidation was achieved using 254-nm radiation at a flow rate of 3.32 mL min-1, with a sample volume of 682 µL. The solution was passed to a fluorimetric detector for recording of the emission spectra (excitation 358 nm, emission 298 nm). The calibration graph was rectilinear in the range 31 ng to 6.24 µg mL-1 of I. In the determination of 0.56 µg mL-1 of I, the coefficient of variation of peak height was 1.9% (n = 34) and the injection rate was 59 samples h-1. The method was used for the determination of I in tablets and suppositories. The influence of excipients is discussed.
Chlorpromazine Fluorescence Photochemistry Interferences UV reactor

"Flow Injection Spectrophotometric Determination Of Piroxicam"
J. Pharm. Biomed. Anal. 1993 Volume 11, Issue 10 Pages 933-938
C. Sánchez-Pedreño*, M. S. Garcia, M. I. Albero and J. Rodriguez

Abstract: Methanolic sample solution was injected into a carrier stream of methanol (1.2 ml/min) which merged with a stream of methanolic 0.1 M HCl and passed through a reaction coil (70 cm long) before detection at 332 nm. Alternatively, the carrier stream merged with a stream of methanolic 5 mM Fe(III); in this instance, detection was at 520 nm. Calibration graphs were linear for 0.15-15 and 30-500 µg/ml of piroxicam with use of detection at 332 and 520 nm, respectively; corresponding detection limits were 0.15 and 7.5 µg/ml. Recoveries were >98% for the two methods, and sample throughput was 90/h. The method was used to analyze suppositories, tablets, capsules, creams and ampoules. Two flow injection analysis (FIA) methods are proposed for the determination of piroxicam. The first involves measurement of the UV absorbance of a solution containing the drug, methanol and hydrochloric acid at 332 nm; in the second method a Fe(III)-piroxicam complex is formed in a methanolic medium and the absorbance is measured at 520 nm. In both methods, the peak height is used as a quantitative parameter and piroxicam is determined over the ranges 0.5-15 and 30-500 µg mL-1, respectively. The methods have been applied to the routine determination of the drug in dosage forms.
Piroxicam Spectrophotometry Complexation

"Flow Injection Spectrofluorimetric Determination Of Flufenamic And Mefenamic Acid In Pharmaceuticals"
J. Pharm. Biomed. Anal. 1995 Volume 13, Issue 9 Pages 1113-1117
M. I. Albero, C. Sanchez-Pedreño* and M. S. Garcia

Abstract: Capsule powder or suppositories equivalent to 250 mg mefenamic acid (I) were dissolved in 96% ethanol, filtered and the filtrate was diluted with ethanol. Cream was dissolved in ethanol. Portions (84 µL) were injected into a stream (1 ml/min) of ethanolic 3.7 mM Al(III), passed through a reactor (1.6 m x 0.5 mm i.d.) and the fluorescence was measured at 440 nm (excitation at 351 nm) for flufenamic acid (II) or at 454 nm (excitation at 355 nm) for I. The calibration graphs were linear for 0.02-1.2 and 0.3-16.1 µg/ml II and I, respectively, and the corresponding quantitation limits were 0.008 and 0.18 µg/ml. The RSD were 1.26% and 1.3%, respectively (n = 10); no interference was observed. Sample throughout was 90/h. The results agreed well with those obtained by the titrimetric British Pharmacopoeia method. Recoveries were 98-101%. Two sensitive and rapid flow injection (FI) spectrofluorimetric methods are proposed for the determination of flufenamic acid (FF) and mefenamic acid (MF), based on the formation of complexes of these compounds with A1(III) in an ethanolic medium. The calibration graphs resulting from the measurements of the fluorescence at lambda exc = 351 nm and lambda em = 440 nm, and lambdaexc = 355 nm and lambda em = 454 nm for the complexes with FF and MF, respectively, are linear over the range 0.030-1.20 µg mL-1 for FF and 0.30-16.1 µg mL-1 for MF. The methods have been applied to the determination of these drugs in pharmaceutical preparations.
Drugs Mefenamic acid Flufenamic acid Fluorescence Interferences Method comparison

"Flow Injection Spectrophotometric Determination Of Diclofenac Sodium In Pharmaceuticals And Urine Samples"
J. Pharm. Biomed. Anal. 1998 Volume 17, Issue 2 Pages 267-273
M. Soledad García, M. Isabel Albero, Concepción Sánchez-Pedreño* and José Molina

Abstract: A fast and sensitive flow injection spectrophotometric method for the determination of diclofenac sodium based on the formation of colored compound with Ce(IV) ammonium nitrate and 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) in 3 x 10^-2 M H2SO4 medium is presented. Using the peak height as a quant. parameter, diclofenac was determined at 580 nm over the concentration. range of 0.20-8.0 µg/mL. The proposed method was applied to the determination of diclofenac in pharmaceutical preparations and urine samples.
Diclofenac Spectrophotometry