Spectrofluorimetric Assessment of Metoclopramide Hydrochloride Using Terbium Doped in PMMA Matrix Optical Sensor

A new, simple and accurate spectrofluorimetric method for the determination of metoclopramide hydrochloride was developed. The metoclopramide hydrochloride can remarkably enhance the luminescence intensity of the Tb³⁺ ion doped in PMMA matrix at λ_ex = 360 nm in methanol at pH 6.9. The intensity of the emission band at 545 nm of Tb³⁺ ion doped in PMMA matrix is increased due to the energy transfer from metoclopramide hydrochloride to Tb³⁺ in the excited stated. The effect of different parameters, e.g., pH, temperature, Tb³⁺ concentration, foreign ions that control the fluorescence intensity of the produced ion associate was critically investigated. The calibration curve of the emission intensity at 545 nm shows linear response of metoclopramide over a concentration range of 5 × 10⁻⁵–5.0 × 10⁻⁸ M with detection limit of 8.7 × 10⁻¹⁰ M. The method was used successfully for the determination of metoclopramide in pharmaceutical preparations and human serum. The average recovery of 99.48% with standard deviation of 0.32% and 96.98% with standard deviation of 0.4%, of pharmaceutical preparations and human serum respectively, were obtained which compared will with the results obtained from standard LC method of average recovery 99.04% and standard deviation of 0.6% and average recovery of 98.19% with standard deviation of 0.6% of pharmaceutical preparations and human serum, respectively.     

NMR Studies Of Drugs. Chiral Solvating Agents for Direct Determination of Enantiomeric Excess of the Cardiac Antiarrhythmic,Mexiletine

The 400 MHz ¹H NMR spectra of the cardiac antiarrhythmic, mexiletine, 1, have been studied with different chiral solvating agents (CSA) to obtain a very promising method for direct determination of enantiomeric excess (e.e.) with limited amounts of 1. The methods included the use of β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), α-methoxy-α-(trifluoromethyl)phenylacetic acid (MTPA), and 2,2,2-trifluoro-1-(9-anthryl)ethanol (TFAE). Use of TFAE in CDCl₃ with the free base of 1 appeared to give the best results, with enantiomeric shift differences observed for the signals of the sidechain methyl, CH ₃CH, and the aryl methyls.     

FTIR Spectrophotometric Methods Used for Antioxidant Activity Assay in Medicinal Plants

Abstract: Fourier transform infrared spectroscopy (FTIR) is a fast and nondestructive analytical method. Associated with chemometrics, it is a powerful tool for research and industry. The present review discusses the antioxidant activities assay of some plants (fruits, leaves, aerian part) with medicinal properties using an FTIR spectrophotometric method in comparison with other ultraviolet-visible (UV-Vis) spectrophotometric methods. A good correlation was found between the different methods used for measuring the antioxidant capacity of some of these herbs.     

1,2-Naphthoquinone-4-Sulphonic Acid Sodium Salt (NQS) as an Analytical Reagent for the Determination of Pharmaceutical Amine by Spectrophotometry

Abstract: Several papers have been presented in recent years regarding the field of application of 1,2-naphthoquinone-4-sulphonic acid sodium salt (NQS) as a chromogenic reagent for the determination of pharmaceutical amines using spectrophotometry. In this review article, various spectrophotometric methods using NQS as a labeling reagent for determination of pharmaceutical amines are presented. The application of these methods for the determination of drugs in pharmaceutical formulations and real samples is discussed.     

Health risk assessment of neonicotinoid insecticide residues in pistachio using a QuEChERS-based method in combination with HPLC-UV

There is an increasing need to address the potential risks arising from combined exposures to multiple residues from pesticides in the diet. Pesticide residue-related pollution is a problem that arises because of the increased use of pesticides in agriculture to meet the growing demands of food production. In this study, pesticide residue data were obtained based on an optimized extraction method. For this purpose, we established a method based on qu ick, e asy, ch eap, e ffective, r ugged, and s afe (QuEChERS) extraction for simultaneous determination of imidacloprid (IMI) and acetamiprid (ACT) in pistachio nuts. The parameters influencing the QuEChERS method were the sample-to-water ratio and adsorbent amounts. As a result, both were optimized to improve the recovery of the analytes as well as the clean-up efficiency of the pistachio matrix. Our results indicated that a freeze-out step and use of primary and secondary amines as an adsorbent led to much cleaner chromatograms with lower baseline drift, without using graphitized carbon black and C₁₈-based adsorbent, which reduced both cost and time of analysis. Following extraction, the pesticide residues were separated and quantified by reverse-phase HPLC. For validation purposes, recovery studies were carried out using a concentration range from 20 to 2500 μg/L at nine levels. The suitable linearity, precision, and accuracy were obtained with HPLC–UV with recoveries of 70.37%–89.80% for IMI and 81.05%–113.57% for ACT, with relative standard deviations <12%. The validated method was successfully applied to the analysis of pistachio samples collected from a field trial to estimate maximum residue limits. There was no significant health risk for consumers via pistachio consumption.     

High-performance liquid chromatographic enantioseparation of drugs containing multiple chiral centers on polysaccharide-type chiral stationary phases

Enantioseparation of drugs with multiple chiral centers is challenging. This article describes resolution of some drugs with multiple chiral centers using polysaccharide-type chiral stationary phases. Also, the use of the column-switching technique is demonstrated to achieve the resolution of this type of compounds.     

Validated analysis of fluvastatin in a pharmaceutical capsule formulation and serum by capillary electrophoresis

The capillary electrophoretic behavior and the determination of fluvastatin (FLU) in capsule and serum is described in this study. Method development was conducted in a fused-silica capillary (L = 86 cm, L(eff) = 58 cm and 75 microm i.d.) and a background electrolyte consisting of 10 mM borate at pH 8 was used. The separation was performed by current-controlled system applying 41 microA, detecting at 239 nm and injecting 0.5 s vacuum injection. A good electropherogram and excellent repeatability was obtained. FLU and phenobarbital sodium (internal standard) migrated (with RSD%) at 4.8 (0.3) min and 5.2 (0.6) min, respectively. Limit of detection (LOD) and limit of quantitation (LOQ) values were found to be 1 x 10(-6) M and 2.89 x 10(-6) M, respectively. Linearity in the range of 1.03 x 10(-5) -5.15 x 10(-5) M was examined employing intra-day and inter-day studies and well-correlated calibration equations were obtained. FLU in a capsule (Lescol 40 mg declared) was found to be 41.9 +/- 0.4 mg. Furthermore, FLU was determined in serum applying standard addition technique. Good repeatability and no interference were observed. The method proposed is simple, sensitive, precise and easy to use for the determination of FLU in capsule and serum.     

Stability-Indicating Methods for the Determination of Luliconazole by TLC and HPTLC-Densitometry in Bulk Powder and Cream Dosage Form

JPC – Journal of Planar Chromatography – Modern TLC - Rapid and sensitive thin-layer chromatography (TLC) and high-performance thin-layer chromatography (HPTLC)—densitometry...     

Potentiometric membrane sensor for the selective determination of pethidine in pharmaceutical preparations and biological fluids

The construction and general performance characteristics of a novel potentiometric PVC membrane sensor based on pethidine-phosphomolybdate as electroactive material for the determination of pethidine are described. This sensor exhibits fast, stable and near-Nernstain response 55.24 +/- 0.1, over the concentration range 1.10(-2)-1.10(-5)M for pethidine-phosphomolybdate over pH 2-7. No interferences are caused by many organic, inorganic cations, alkaloids and amino acids. The sensor proved useful for determining pethidine in pure forms, pharmaceutical injections and monitoring the content uniformity assay of ampoules. The designed sensor also show good accuracy for the determination of pethidine in biological fluids.