A New Luminescence Spectrometry for the Determination of Some β-Lactamic Antibiotics

Perovskite quantum dots as a chemiluminescence platform for highly sensitive assay of cefazolin

This paper reports on a chemiluminescence (CL) probe consist of CsPbBr₃ quantum dots (QDs) in organic phase together with Fe(II) and K₂S₂O₈ in aqueous medium for the highly selective and sensitive determination of the antibiotic, cefazolin (CFZ). The CsPbBr₃perovskite QDs prepared by the ligand assisted reprecipitation method, exhibit a narrow fluorescence at 533 nm under 460 nm excitation with a high quantum yield (42 %). The Fe(II) - S₂O₈^2- as an ultra-weak CL system is converted to a rather strong CL sensing platform in the presence of organic-phase CsPbBr₃ QDs. It was observed that CFZ exerts an enhancement effect on the CL signal of the designed probe in the linear range of 25 - 300 nM, with a low limit of detection (9.6 nM). The introduced sensor has broad application prospects in biosensing, food detection, and other fields with recovery ranging from 94 to 106 %.

Determination of Cefalothin and Cefazolin in Human Plasma, Urine and Peritoneal Dialysate by UHPLC-MS/MS: application to a pilot pharmacokinetic study in humans

An ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the analysis of cefazolin and cefalothin in human plasma (total and unbound), urine and peritoneal dialysate has been developed and validated. Total plasma concentrations are measured following protein precipitation and are suitable for the concentration range of 1-500 µg/mL. Unbound concentrations are measured from ultra-filtered plasma acquired using Centrifree(®) devices and are suitable for the concentration range of 0.1-500 µg/mL for cefazolin and 1-500 µg/mL for cefalothin. The urine method is suitable for a concentration range of 0.1-20 mg/mL for cefazolin and 0.2-20 mg/mL for cefalothin. Peritoneal dialysate concentrations are measured using direct injection, and are suitable for the concentration range of 0.2-100 µg/mL for both cefazolin and cefalothin. The cefazolin and cefalothin plasma (total and unbound), urine and peritoneal dialysate results are reported for recovery, inter-assay precision and accuracy, and the lower limit of quantification, linearity, stability and matrix effects, with all results meeting acceptance criteria. The method was used successfully in a pilot pharmacokinetic study with patients with peritoneal dialysis-associated peritonitis, receiving either intraperitoneal cefazolin or cefalothin. Copyright © 2015 John Wiley & Sons, Ltd.

Development of a novel chemiluminescence method for the determination of cefazolin sodium in injectable powder and human urine based on a luminol-Cu(III) complex reaction in alkaline medium

A novel chemiluminescence (CL) method was developed for the determination of cefazolin sodium based on the CL reaction between the [Cu(HIO6)2](5-) Cu(III) complex and luminol in alkaline solution. Results showed that CL emission of Cu(III) complex-luminol in alkaline medium was significantly different from that in acidic medium. A possible mechanism of the enhanced effect of cefazolin on CL emission of the [Cu(HIO6)2](5-)-luminol system was proposed. The effect of the reaction conditions on CL emissions was examined. Under optimized conditions, a good linear relationship was obtained between CL intensity and concentrations of cefazolin sodium in the range of 2.0 x 10(-8) to 2.0 x 10(-6) g/mL with a correlation coefficient of R(2) = 0.9978. The limit of detection was 4.58 x 10(-9) g/mL. The proposed method was applied for the determination of cefazolin sodium in real samples with recoveries of 82.0-109% with an RSD of 0.7-2.1%. The proposed method was successfully used for the determination of cefazolin sodium in injectable powder preparations and human urine with satisfactory results.

Improved spectrofluorimetric methods for determination of penicillamine in capsules

Two simple, sensitive and specific fluorimetric methods have been developed for the determination of Penicillamine (PNC), a sulphur containing compound. Method (I) involves the reaction of PNC with 2′,7′-bis(acetoxymercuri)-fluorescein (AMF) in the presence of Kolthoff’s buffer, pH 8.2, with subsequent measurement of fluorescence spectra at 520 nm (λEx 497 nm). Method (II) is based on PNC being oxidized into penicillaminic acid using Cerium (IV) in an acidic medium. Method sensitivity has been improved using sodium triphosphate which enhances the luminescence intensity of Ce(III). Fluorescence spectra were then measured at 348 nm (λEx 293 nm). The reaction conditions and the fluorescence spectral properties have been investigated for both methods. Under the described conditions, the proposed methods were applicable over the concentration ranges 0.0048 − 0.0288 µg mL−1 and 0.096 − 0.288 µg mL−1 with mean percentage recoveries 99.95 ± 1.29 and 100.04 ± 1.10 for methods I and II, respectively. The proposed methods were validated in terms of accuracy, precision, LOD and LOQ and robustness and then were successfully applied to the determination of PNC in bulk powder and in capsules as well as in the presence of the related disulphide. The results obtained were determined to be in good agreement with those obtained using a previously reported method.

Kinetic spectrophotometric determination of certain cephalosporins using oxidized quercetin reagent

A simple, precise and accurate kinetic spectrophotometric method for determination of cefoperazone sodium, cefazolin sodium and ceftriaxone sodium in bulk and in pharmaceutical formulations has been developed. The method is based upon a kinetic investigation of the reaction of the drug with oxidized quercetin reagent at room temperature for a fixed time of 30 min. The decrease in absorbance after the addition of the drug was measured at 510 nm. The absorbance concentration plot was rectilinear over the range 80-400 microg mL(-1) for all studied drugs. The concentration of the studied drugs was calculated using the corresponding calibration equation for the fixed time method. The determination of the studied drugs by initial rate, variable time and rate-constant methods was feasible with the calibration equations obtained but the fixed time method has been found to be more applicable. The analytical performance of the method, in terms of accuracy and precision, was statistically validated; the results were satisfactory. The method has been successfully applied to the determination of the studied drugs in commercial pharmaceutical formulations. Statistical comparison of the results with a well established reported method showed excellent agreement and proved that there is no significant difference in the accuracy and precision.

Analysis of cephalosporin antibiotics

A comprehensive review with 276 references for the analysis of members of an important class of drugs, cephalosporin antibiotics, is presented. The review covers most of the methods described for the analysis of these drugs in pure forms, in different pharmaceutical dosage forms and in biological fluids.

Utilization of colorimetric and atomic absorption spectrometric determination of aztreonam through ion pair complex formation

Three rapid and sensitive, colorimetric and atomic absorption spectrometric methods were developed for the determination of aztreonam. The proposed methods depend upon the reaction of cobaltthiocyanate (I) or reineckate (II) ions with the drug to form stable ion-pair complexes which extractable with chloroform. The greenish blue and pink color complexes are determined either colorimetrically at lambda(max) 625 and 525 nm for I and II reagents, respectively, or by atomic absorption spectrometry, directly using the organic extracted complex, or indirectly, using the supernatant. The three procedures are applied for the determination of aztreonam in pure and in pharmaceutical dosage forms applying the standard additions technique and the results obtained agreed well with those obtained by the official method.