Development of sensitive benzofurazan-based spectrometric methods for analysis of spectinomycin in vials and human biological samples

Quantification of tyramine in different types of food using novel green synthesis of ficus carica quantum dots as fluorescent probe

Tyramine (TYM) is catecholamine releasing compound, tyramine rich food causing hypertensive crisis due to combination with monoamine oxidase inhibitor (MAOIs). So, Analysis of TYM in tyramine rich food (old cheese, cured meat, sausage, pickled olive and canned fish) and environment is very essential for hypertensive patients and improvement food industries. In this work, TYM was analyzed in different types of food using novel green synthesis carbon dots from ficus carica (Fig fruits). The gradual addition of TYM to PA@CQDs led to enhancement of the quantum dots fluorescence due to formation of hydrogen bonding between quantum dots and TYM. The calibration graph plotted in the range 5-400 ng mL^-1 . The method was applied to determination of TYM in different types of food as old cheese, cured meat, sausage, pickled olive and canned fish. The lower limit of quantitation (LOQ) was found to be 1.68 ng mL^-1 . The method successfully applied for the quantification of TYM in varying types of food with high sensitivity and high economic effect due to the reusability of the quantum dots. The optical and morphological characters of quantum dots were studied carefully.

Bio-analytically fluorimetric method for estimation of ertapenem in real human plasma and commercial samples; Application to pharmacokinetics study

Ertapenem (EPM) is recently approved via FDA as antimicrobial drug. EPM has a broad spectrum against different bacterial strains and most common prescribed in Egypt for treatment klebsiella pneumonia. In this study, EPM was estimated using sensitive and selective spectrofluorimetric method in human plasma and pharmaceutical vial. The measured fluorescence (at 540 nm) obtained from reaction of EPM with 0.05 % w/v NBD-Cl (benzofurazan) using 0.1 M borate buffer pH 8.8 after excitation at 460 nm. The fluorometric linear range is stabilized from 10 to 350 ng mL^-1 . The lower limit of detection (LOD) and the lower limit of quantitation (LOQ) was found to be 2.13 and 6.47 ng mL^-1 respectively. Many factors as pH, temperature and heating time and NBD-Cl concentration were optimized. The presented work was validated according to ICH guidelines and bioanalytically validated using FDA recommendations. The significant of this study and sensitivity was successfully applied in pharmacokinetic study and commercial vial in Egypt. The pharmacokinetic parameters were studied and result recorded as C_max of EPM was found 83.60 μ mL^-1 after infusion 0.5 g of Invanz® for 30 min and AUC_0-ꝏ was found to be 320 ± 30.2 μ.h mL^-1 .

Ultra-Sensitive Fluorimetric Method for the First Estimation of Vonoprazan in Real Human Plasma and Content Uniformity Test

Vonoprazan (VON) has been approved recently via US-FDA in 2015 as the first in class of potassium competitive acid blocker group. VON is used for management of GIT ulcer, reflux esophagitis and for eradication of Helicobacter pylori. So, the first spectrofluorimetric method was developed for estimation of VON in real human plasma and content uniformity test. The fluorimetric methodology based on reaction of secondary amine group in VON with benzofurazan (0.05% w/v NBD-Cl) reagent as nucleophilic substitution reaction in alkaline medium (0.1 M borate buffer pH 8.2) to produce highly fluorescent product measure at 530 nm after excitation at 465 nm. The linear calibration range was found 15 to 200 ng mL^-1 with lower limit of quantitation (LOQ) equal to 8.57 ng mL^-1. The method was successfully applied for estimation of VON in pharmacokinetic (PK) and content uniformity studies. The maximum plasma concentration was found to be (C_max) 71.03 ng mL^-1 after maximum time (t_max) equal to 1.5 ± 0.15 h. The presented strategy also applied to ensure concentration of drug in each tablet using content uniformity test with high percent of recovery 100.05 ± 0.66. The proposed method was established for clinical laboratories and therapeutic drug monitoring studies.