An HPLC Method for the Determination of Saxagliptin in Human Plasma with Fluorescence Detection

A sensitive and selective HPLC method with fluorometric detection was developed for the determination of saxagliptin (SGX) in human plasma and applied to a pharmacokinetic study. SGX was precolumn derivatized with fluorescamine, and the fluorescent derivative was separated on an RP C18 column using a mobile phase composed of acetonitrile-10 mM orthophosphoric acid by isocratic elution with flow rate of 1.3 ml/min. The method was based on the measurement of the derivative using fluorescence detection at 378 nm, with excitation at 463 nm. The calibration curve was linear over the range of 3.0“100.0 ng/ml. LOD and LOQ were found to be 0.15 and 0.5 ng/ml, respectively. Intraday and interday RSD values were less than 2.84%. The plasma concentration“time profile and pharmacokinetic parameters such as AUC0–t, AUC0–∞, Cmax, tmax, t1/2, were calculated according to the assays

Valsartan (Profiles of Drugs Substances, Excipients and Related Methodology)

Valsartan is an antihypertensive drug which selectively inhibits angiotensin receptor type II. This tetrazole derivative was first developed by Novartis and marketed under brand name Diovan® . This compound is orally active and is rapidly absorbed after oral doses, having a bioavailability of approximately 23% . Valsartan appears as a white or almost white hygroscopic powder. This compound must be kept in an air-tight container and should be protected from light and heat. It is available in film-coated tablets containing valsartan 40, 80, 160, or 320 mg, and capsules with dosage of 80 or 160 mg. Tablet combinations of valsartan with hydrochlorothiazide or amlodipine are also availabl

Development of an HPLC-UV Method for the Analysis of Drugs Used for Combined Hypertension Therapy in Pharmaceutical Preparations and Human Plasma

A simple, rapid, and selective HPLC-UV method was developed for the determination of antihypertensive drug substances: amlodipine besilat (AML), olmesartan medoxomil (OLM), valsartan (VAL), and hydrochlorothiazide (HCT) in pharmaceuticals and plasma. These substances are mostly used as combinations. The combinations are found in various forms, especially in current pharmaceuticals as threesome components: OLM, AML, and HCT (combination I) and AML, VAL, and HCT (combination II). The separation was achieved by using an RP-CN column, and acetonitrile-methanol-10 mmol orthophosphoric acid pH 2.5 (7 : 13 : 80, v/v/v) was used as a mobile phase; the detector wavelength was set at 235 nm. The linear ranges were found as 0.1–18.5 μg/mL, 0.4–25.6 μg/mL, 0.3–15.5 μg/mL, and 0.3–22 μg/mL for AML, OLM, VAL, and HCT, respectively. In order to check the selectivity of the method for pharmaceutical preparations, forced degradation studies were carried out. According to the validation studies, the developed method was found to be reproducible and accurate as shown by RSD ≤6.1%, 5.7%, 6.9%, and 4.6% and relative mean error (RME) ≤10.6%, 5.8%, 6.5%, and 6.8% for AML, OLM, VAL, and HCT, respectively. Consequently, the method was applied to the analysis of tablets and plasma of the patients using drugs including those substances

A New HPLC Method with Fluorescence Detection for the Determination of Memantine in Human Plasma

A sensitive and selective HPLC method with fluorometric detection was developed for the determination of memantine in human plasma and applied to a pharmacokinetic study. Memantine was precolumn derivatized with 9-fluorenylmethyl chloroformate, and the fluorescent derivative was separated on an RP C18 column using a mobile phase composed of acetonitrile-10 mM orthophosphoric acid containing 1 mL/L triethylamine with gradient elution. The method was based on the measurement of the derivative using fluorescence detection at 310 nm with excitation at 260 nm. The calibration curve was linear over the range 1.0-50.0 ng/mL. LOD and LOQ were found to be 0.3 and 1.0 ng/mL, respectively. Intraday and interday RSD values were less than 3.39%

Spectrofluorimetric Methods for the Determination of Gemifloxacin in Tablets and Spiked Plasma Samples

Two new, sensitive and selective spectrofluorimetric methods have been developed for the determination of gemifloxacin (GFX) in tablets and spiked plasma samples. Gemifloxacin, as a primary amine compound, reacts with 7-chloro-4-nitrobenzofurazon (NBD-Cl) (for method A) and fluorescamine (for method B) which are a highly sensitive fluorogenic reagents used in many investigations. For method A, the reaction product was measured spectrofluorimetrically at 516 nm with excitation at 451 nm. The reaction proceeded quantitatively at pH 8.5, 80 A degrees C in 7 min. For method B, the method was based on the reaction between GFX and fluorescamine in borate buffer solution of pH 8.5 to give highly fluorescent derivatives that were measured at 481 nm using an excitation wavelength of 351 nm. The fluorescence intensity was directly proportional to the concentration over the range 40-200 ng mL(-1) and 100-1,200 ng mL(-1) for method A and B, respectively. Successful applications of the developed methods, for the drug determination in pharmaceutical preparations and spiked plasma samples, were performed

A Review of Current Methods for the Determination of Acrylamide in Food Products

Acrylamide (AA) is a potentially carcinogenic substance which is formed during heating of food products containing carbohydrates and asparagine. It was first detected in food products in 2002. Since that time, several analytical methods have been made available for the quantification of AA in various foods. Starting from the announcement in 2002, occurrence, formation, chemistry, toxicology, and potential health risk in the human diet have been investigated and methods of analysis have been reviewed in many articles. In this paper, current information and analytical methods for the determination of AA have been reviewed

Development and Validation of Spectrophotometric Methods for the Determination of Rasagiline in Pharmaceutical Preparations

This study presents three simple, rapid, and accurate spectrophotometric methods for the determination of Rasagiline (RSG) in pharmaceutical preparations. The determination procedures depend on the reaction of RSG with chloranilic acid for method A, tetrachloro-1,4-benzoquinone for method B, and 7,7,8,8-tetracyanoquinodimethane for method C. The colored products were quantitated spectrophotometrically at 524, 535, and 843 nm for methods A, B, and C, respectively. Different variables affecting the reaction were optimized. Linearity ranges of the methods with good correlation coefficients (0.9988-0.9996) were observed as 25-300 g mL −1 , 25-350 g mL −1 , and 50-500 g mL −1 for methods A, B, and C, respectively. The formation of products takes place through different mechanisms. The sites of interaction were confirmed by elemental analysis using IR and 1 H-NMR spectroscopy. The validation of the methods was carried out in terms of specificity, linearity, accuracy, precision, robustness, limit of detection, and limit of quantitation. No interference was observed from concomitants usually present in dosage forms. The methods were applied successfully to the determination of RSG in pharmaceutical preparations

Determination of Apigenin in Cosmetics Containing Chamomile by High-Performance Liquid Chromatography with Ultraviolet Detection (HPLC-UV)

© 2022 Taylor & Francis Group, LLC.A simple, rapid, and precise high performance liquid chromatography (HPLC) method was developed to determine the flavonoid apigenin in cosmetic products containing chamomile extracts. A C18 column was used as stationary phase and 70:30 ethanol:water was used as mobile phase with a 1 mL/min flow rate and isocratic elution. The temperature was stabilized at 25 °C during the separation. The injection volume was 50 μL. The apigenin peak was eluted at 4.15 ± 0.4 min. The method was validated according to International Conference on Harmonisation (ICH) criteria in terms of linearity, limit of detection, limit of quantitation, selectivity, sensitivity, robustness, accuracy, and precision. The limits of detection and quantitation were 0.060 and 0.2 μg/mL respectively. The linear range was from 0.2 to 20 μg/mL. The relative standard deviation values for intraday and interday analyses were less than 1.64%. The developed procedure was applied to the analysis of various cosmetic products. It is expected that the method is suitable for routine analysis, quality control and standardization of cosmetic products for apigenin