Determination Of Cephalexin Research Articles

Экспресс-определение цефалексина

Test means based on immobilized Fehling’s reagent for the determination of cephalexin have been obtained. Methods for visual and colorimetric assessment of antibiotic concentration using a smartphone camera have been developed. The optimal conditions for the indicator reaction have been selected with varying heating time and temperature. For a visual semi-quantitative assessment of the content of cephalexin, a color scale has been obtained. The metrological characteristics of the test method have been determined: the range of the determined contents is 0.5–16 mg/ml, the unreliability interval is 0.1–0.4 mg/ml, and the detection limit is 0.4 mg / ml. For the colorimetric assessment of the concentration of cephalexin, a linear dependence of the intensity of the Blue channel on the logarithm of the concentration of cephalexin (у = –96x + 144, r 2 = 0.99) has been constructed, and linear dependences of the area (у = –36986x + 62458, r 2 = 0.96) and perimeter (у = –270x + 786, r 2 = 0.93) from the logarithm of the concentration of cephalexin have been obtained. The range of the determined contents was 0.1–16 mg/ml, the lower limit was 0.1 mg / ml. The verification of the correctness of the developed test methods was carried out by the «introduced-found» method (Sr  0.13).

Validation of Liquid Chromatographic Analytical Method for Determination of Cephalexin and Aspirin in Pure and Pharmaceutical Preparations

Validation of Liquid Chromatographic Analytical Method for Determination of Cephalexin and Aspirin in Pure and Pharmaceutical Preparations

Analytical Method for Determination of Cephalexin in Bovine Edible Tissues using Liquid Chromatography Coupled to Tandem Mass Spectrometry

Analytical Method for Determination of Cephalexin in Bovine Edible Tissues using Liquid Chromatography Coupled to Tandem Mass Spectrometry

Development and Validation of a New Spectrophotometric Method for the Determination of Cephalexin Monohydrate in Pure Form and Pharmaceutical Formulations

A simple, fast, sensitive and accurate spectrophotometric method has been developed for the quantitative determination of cephalexin monohydrate in dosage form and in commercial formulations. The method involves the addition of CeIV to cephalexin in acidic medium, followed by the determination of residual CeIV by reacting with a fixed amount of methyl orange, and the absorbance was measured at 510 nm. Beer's law was obeyed in the concentration range of 0.6-20 µg mL-1 with correlation coefficient of 0.992. The molar absorptivity was calculated and was found to be 9.8 × 104 L mol-1 cm-1. Different variables affecting the reaction conditions such as concentration and volume of CeIV, type and concentration of acids used, reaction time and temperature were carefully studied and optimized. The limit of detection (LOD) and limit of quantification (LOQ) were calculated and found to be 0.221 and 0.736 µg mL-1, respectively. The proposed method was found to have good reproducibility with a relative standard deviation of 4.4% (n = 9). The interference effects of common excipients found in pharmaceutical preparations were studied. The developed method was validated statistically by performing recoveries studies and successfully applied for the determination of cephalexin in bulk powder and pharmaceutical preparations. Percent recoveries were calculated and found to range from 90.6 to 102.9% for bulk powder and from 98.7 to 104.8% for pharmaceutical preparations.

A Homogeneous Fluorescence Polarization Immunoassay for the Determination of Cephalexin and Cefadroxil in Milk

A new monoclonal antibody (mAb) against cephalexin (CEX), named 1F3, was produced by immunizing mice with immunogen CEX–keyhole limpet hemocyanin. Two fluorescein-labeled tracers (CEX–fluorescein isothiocyanate (FITC) and cefadroxil (CDX)–FITC) were synthesized and purified by thin-layer chromatography. A homogeneous fluorescence polarization immunoassay (FPIA) based on the new mAb and the selected tracer for the simultaneous determination of CEX and CDX was developed and optimized. The optimized FPIA provided a limit of detection of 1.8 and 2.3 ng ml−1 for CEX and CDX and exhibited cross-reactivities of 100 and 63.16 % for CEX and CDX, respectively, and <1 % for other 11 cephalosporins. Recoveries from fortified milk were ranged from 82 to 125 % with coefficient of variations of 3.2–14.2 %. The results indicated that the homogeneous FPIA we developed was enough sensitive to rapidly monitor CEX and CDX in milk.

Determinação espectrofotométrica de cefalexina em formulações farmacêuticas explorando a sua reação de transferência de carga com a quinalizarina

This work proposes a new simple and fast spectrophotometric method for cephalexin determination in pharmaceutical formulations. The method is based on the charge transfer reaction between cephalexin and quinalizarin in dimethylsulfoxide medium. Several analytical parameters related to the system were optimized and the reaction was characterized in terms of stoichiometry. Also, association constant and apparent molar absorptivity of the product were determined. The method presented a limit of detection of 0.46 mg L-1 and a quantification limit of 1.5 mg L-1. It was successfully applied in the determination of cephalexin in two samples of commercial pharmaceutical formulations.

Liquid Chromatographic Analysis of Cephalexin in Human Plasma by Fluorescence Detection of the 9-Fluorenylmethyl Chloroformate Derivative

A simple and sensitive precolumn derivatization method for the determination of cephalexin in human plasma has been developed. Cephalexin was derived with 9-fluorenylmethyl chloroformate (FMOC-Cl) in borate buffer (5 mM, pH 8.5) for 15 min at 25°C. Optimal conditions for the derivatization were described. The derivative was chromatographed on an XDB-C18 column with water–acetonitrile (10:90, v/v) as mobile phase at a flow rate of 1.0 mL/min. The fluorescence excitation and emission wavelengths were 268 nm and 314 nm, respectively. The standard curve in spiked plasma was linear over the range of 0.0234–58.5 µg/mL; the detection limit (signal-to-noise ratio = 3; injection volume, 10 µL) was about 0.014 µg/mL. The performance of analysis was studied, and the validated method showed excellent performance in terms of selectivity, sensitivity, precision, and accuracy.

Spectrofluorometric Determination of Cephalexin in Pharmaceutical Preparations and Spiked Human Urine Using 2‐Cyanoacetamide

A simple, accurate, sensitive, and validated method was developed for the spectrofluorometric determination of cephalexin. The method involves the reaction of cephalexin with 2‐cyanoacetamide in presence of 33% ammonia solution. The formed fluorescent product exhibited maximum fluorescence intensity at λ 439 nm, after excitation at λ 339 nm. Different experimental parameters affecting the derivatization reaction were carefully studied and incorporated in the procedure. Under the described conditions, the proposed method was linear over the concentration range 0.04–0.4 µg/mL. The average percent found was 99.6±0.9%. The LOD was 7.76 ng/mL. The proposed method was applied for determination of cephalexin in pharmaceutical preparations as well as in spiked human urine. A mechanism of the reaction is postulated.

Vanadophosphoric Acid as a Modified Reagent for the Spectrophotometric Determination of Certain Cephalosporins and their Dosage Forms

Vanadophosphoric acid in acidic medium is proposed as a modified reagent for the spectrophotometric determination of cephalexin, cephaprine sodium, cefazolin sodium, and cefotaxime in pure samples and in pharmaceutical preparations. The method is based on acid hydrolysis of cephalosporins and subsequent oxidation with vanadophosphoric acid. The resulting solution exhibits maximum absorption at about 516 nm. The effects of reaction conditions were investigated. Lambert-Beer’s law was obeyed over a concentration range of about 0.4–45 μg · cm−3. For more accurate results, Ringbom optimum concentration ranges were obtained, and the molar absorptivities and Sandell sensitivities were derived. The proposed method was applied to the determination of the drugs in pharmaceutical formulations; the results demonstrated that the proposed method is as accurate, pecise, and reproducible as the official methods.

Simultaneous Determination of Cephalexin and Carbocisteine from Capsules by Reverse Phase High Performance Liquid Chromatography (RP - HPLC).

A new, simple, precise, accurate and rapid RP- HPLC method has been developed for the simultaneous determination of Cephalexin and Carbocisteine from capsules, using 0.025 M monobasic sodium phosphate: acetonitrile (87:13, v/v) as a mobile phase, and a C8 Shodex column as the stationary phase. Detection was carried out using a UV detector at 210 nm. The linearity range for Cephalexin and Carbocisteine were 50 - 300 μg/mL and 40 - 200 μg/mL, respectively. Assay values for Cephalexin and Carbocisteine were 99.46% (R.S.D. - 1.30%) and 99.22% (R.S.D.-1.34%) for Brand 1. and 99.71% (R.S.D. - 1.68%) and 99.43% (R.S.D. - 1.78%) for Brand 2, respectively.

Spectrophotometric Method for Determination of Cephalexin in Its Dosage Forms

Abstract A simple, rapid, and specific method was developed for determination of cephalexin and its dosage forms. The method is based on the reaction of cephalexin with acetylacetone-formaldehyde reagent to give a yellow chromophore measurable at 400 nm. The color is stable for 3 h. Beer's law is valid within a concentration range of 10-100 μg/mL for cephalexin. All variables were studied to optimize the reaction conditions. The method is specific for amino β-lactam antibiotics. Non-amino β-lactam antibiotics do not interfere. No interference was observed in the presence of common pharmaceutical adjuvants. The validity of the method was tested by analyzing cephalexin tablets, capsules, and oral suspension. Good recoveries were obtained for these preparations. The results were comparable with those obtained by the official procedure

Simultaneous determination of cefoxitin, cefuroxime, cephalexin and cephaloridine in plasma using HPLC and a column-switching technique

A new high performance liquid chromatographic method was developed using a column-switching technique for the simultaneous determination of cephalexin, cefuroxime, cefoxitin and cephaloridine in plasma. The plasma samples were injected onto a precolumn packed with Corasil RP C18 (37–50 μm) after simple dilution with an internal standard solution in 0.01 M acetate buffer (pH 3.5). Polar plasma components were washed out using 0.01 M acetate buffer (pH 3.5). After valve switching, the concentrated drugs were desorbed in back-flush mode and separated on a Partisil ODS-3 column using acetonitrile in 0.02 M acetate buffer (pH 4.3) (15∶85, v/v) as the mobile phase. The method showed excellent precision with good sensitivity and speed with a detection limit of 0.5 μg/ml. The total analysis time per sample was less than 25 min, and the mean coefficients of variation for intra- and inter-assay were both less than 4.9 %.

Application of thin layer and high performance liquid chromatography to the separation and determination of cephalexin in cephradine, in bulk powder and in pharmaceuticals

A thin-layer chromatographic procedure for the quantitative determination of cephalexin in cephradine formulations is described. The thin-layer chromatography is carried out on a silica gel layer and the quantitation is by UV scanning of the chromatogram. The procedure was transferred to high-performance liquid chromatography on a microparticulate silica gel column with a similar eluent system. The cephalexin content of a few commercial cephradine samples is determined by using these techniques. The results of these procedures are compared to those obtained with high-performance liquid chromatography on a C 18 reverse phase column.

Photometric extraction method for determination of cephalexin.

A photometric extraction method is developed for determination of cephalexin. Cephalexin is hydrolysed for 5 min in sulphuric acid medium on a steam-bath, the hydrolytic product forming a coloured compound with ninhydrin in 25% H2SO4. This compound is extracted with CHCl3 and its absorbance measured at 520 nm. The reaction is selective — it is negative for the initial reagents in the cephalexin synthesis and for most other antibiotics. The only two antibiotics giving a similar reaction — ampicillin and cephalotin — do not interfere in the determination of cephalexin. The method is rather simple and permits rapid determination of cephalexin with satisfactory precision and accuracy — coefficient of variation 0.91–1,36%, relative error of the determination 0.66–1,19% (95% confidence limits).