Validated Sensitive Spectrophotometric methods for Determination of Carvedilol and Nebivolol HCl in dosage forms.

A simple, sensitive and rapid spectrophotometric methods were developed and validated for the determination of two antihypertensive drugs namely, carvedilol and nebivolol hydrochloride in pure form and pharmaceutical formulations. Method (I) is based on the formation of a binary complex between the studied drugs and eosin Y in presence of tween 80 at (pH 3.0).The formed complex exhibited maximum absorption at 545 nm for carvedilol and 543 nm for nebivolol. The concentration plots were rectilinear over concentration range of 0.5-5 and 1-7 µg/mL with lower detection limits of 0.09 and 0.11µg/mL and lower quantitation limits of 0.28 and 0 .34 µg/mL for carvedilol and nebivolol respectively. Method (II) is based on the reaction of studied drugs through their secondary amino groups with 2, 4-dinitrofluorobenzene (DNFB) at pH 8 to form yellow colored reaction products peaking at 383 nm and 390 nm for carvedilol and nebivolol, respectively. The absorbance-concentration plots were rectilinear over the concentration ranges of 5-30 and 4-28 µg/ mLwith the lower detection limits of 0.48 and 0.51 µg/mL and the lower quantitation limits of 1.45 and 1.54 µg/mL for cavredilol and nebivolol respectively. The different experimental parameters affecting the development and stability of the formed complex and reaction products were carefully studied and optimized for both methods. Both methods were successfully applied for determination of the studied drugs in their dosage forms

Simultaneous determination of sulpiride and mebeverine by HPLC method using fluorescence detection: application to real human plasma

A new simple, rapid and sensitive reversed-phase liquid chromatographic method was developed and validated for the simultaneous determination of sulpiride (SUL) and mebeverine Hydrochloride (MEB) in the presence of their impurities and degradation products. The separation of these compounds was achieved within 6 min on a 250 mm, 4.6 mm i.d., 5 m particle size Waters®-C18 column using isocractic mobile phase containing a mixture of acetonitrile and 0.01 M dihydrogenphosphate buffer (45:55) at pH = 4.0. The analysis was performed at a flow rate of 1.0 mL/min with fluorescence-detection at excitation 300 nm and emission at 365 nm. The concentration-response relationship was linear over a concentration range of 10- 100 ng/mL for both MEB and SUL with a limit of detection 0.73 ng/mL and 0.85 ng/mL for MEB and SUL respectively. The proposed method was successfully applied for the analysis of both MEB and SUL in bulk with average recoveries of 100.22 ± 0.757% and 99.96 ± 0.625% respectively, and in commercial tablets with average recoveries of 100.04 ± 0.93% and 100.03 ± 0.376% for MEB and SUL respectively. The proposed method was successfully applied to the determination of MEB metabolite (veratic acid) in real plasma simultaneously with SUL. The mean% recoveries (n = 3) for both MEB metabolite (veratic acid) and SUL were 100.36 ± 2.92 and 99.06 ± 2.11 for spiked human plasma respectively. For real human plasma, the mean% recoveries (n = 3) were and respectively

Inspection of antimicrobial remains in bovine milk in Egypt and Saudi Arabia employing a bacteriological test kit and HPLC-MS/MS with estimation of risk to human health.

Veterinary medicine uses antibiotics randomly for treatment and growth promotion. Milk of dairy animals contains substantial quantities of antibiotics that have harmful effects on health. It is therefore necessary to test commercially available milk using immunological, chromatographic, or microbiological methods to confirm the absence of antibiotic residues. This study aims to perform a microbiological test, followed by a quantitative confirmation analysis, on raw milk to assess the presence of antibiotic residues. Tests were conducted on 200 milk samples collected from markets and farms in Saudi Arabia and Egypt. The microbial inhibitor test (Delvotest SP-NT) revealed that 40 samples were positive for antibiotic residues. The positive samples were further tested using liquid chromatography-tandem mass spectrometry (LC-MS/MS) as a confirmatory quantitative test for 29 antibiotics that belong to five groups: tetracyclines, sulfonamides, fluoroquinolones, macrolides, and lactamases. Only four samples tested positive for oxytetracycline residues above the maximum residue limit. Based on these results, researchers suggest a monitoring system that considers both microbial and HPLC-MS/MS methods when detecting antibiotic residues in bovine milk. The analysis of risk to human health revealed that antibiotic residues at the detected levels do not pose any health risks to consumers

A synchronous spectrofluorometric technique for simultaneous detection of alfuzosin and tadalafil: applied to tablets and spiked biological samples

A facile, accurate, eco-friendly and sensitive spectrofluorometric method was evolved to assay alfuzosin hydrochloride (AFH) and tadalafil (TDF) in different matrices. Such a co-administered combination is clinically used for the treatment of lower urinary tract symptoms. Both compounds are characterized by their native fluorescence spectra upon excitation at specific wavelengths. Their characteristic fluorescence spectra were used for sensitive assay of the studied analytes in tablets and human biological samples. The assay principle is based on first-order synchronous spectrofluorometric scan using Δλ = 60 nm in which AFH peaks were recorded at 366 nm. Meanwhile, TDF measurements were recorded at 293 nm in the same scans without overlap with AFH spectra. Recent analytical chemistry trends were implemented to lessen occupational and environmental perils, using ethanol as a diluting solvent for method optimization and application. Linearity ranges were 5.0–90.0 and 10.0–100.0 ng ml−1 for AFH and TDF, respectively in their raw materials with average % recoveries of 100.44% and 99.73% in raw materials, 100.15% and 100.20% in spiked plasma, and 97.14% and 99.99% in spiked urine. The proposed method was successfully applied to Prostetrol and Starkoprex commercial tablets with no interference with common tablet additives