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- Author or Editor: D. Kumar x
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The objective of the current research is to understand the degradation behavior of avanafil under different stress conditions and to develop a stability-indicating high-performance liquid chromatography (HPLC) method for simultaneous determination of degradants observed during degradation. Avanafil tablets were exposed to acid, base, water, oxidative, thermal, and photolytic degradation conditions. In acid, oxidative, thermal, and humidity degradation, significant degradation was observed. All the degradants observed during degradation were separated from known impurities of avanafil by using reverse-phase (RP)-HPLC. Mobile phase A, 0.1% trifluoro acetic acid and triethylamine in water, and mobile phase B, water and acetonitrile in the ratio of 20:80 (v/v), were used at a flow rate of 1.2 mL/min in gradient elution mode. Separation was achieved by using Inertsil ODS 3 column (3 μm, 4.6 mm × 250 mm) at 45 °C. Peak responses were recorded at 245 nm. Method capability for detecting and quantifying the degradants, which can form during stability, was proved by demonstrating the peak purity of avanafil peak in all the stressed samples. Mass balance was established by performing the assay of stressed sample against reference standard. Mass balance was found >97% for all the stress conditions. The developed analytical method was validated as per International Conference on Harmonization (ICH) guidelines. The method was found specific, linear, accurate, precise, rugged, and robust.
Summary
A simple, selective, and stability-indicating reverse phase liquid chromatographic method has been developed and validated for the simultaneous determination of impurities and forced degradation products of quetiapine fumarate. The chromatographic separation was achieved on Inertsil-3 C8, 150 mm × 4.6 mm, 5 μm column at 35°C with UV detection at 217 nm using gradient mobile phase at a flow rate of 1.0 mL/min. Mobile phase A contains a mixture of 0.01 M di-potassium hydrogen orthophosphate (pH 6.8) and acetonitrile in the ratio of 80:20 (v/v), respectively, and mobile phase B contains a mixture of 0.01 M di-potassium hydrogen orthophosphate (pH 6.8) and acetonitrile in the ratio of 20:80 (v/v), respectively. The drug product was subjected to the stress conditions of oxidative, hydrolysis (acid and base), hydrolytic, thermal, and photolytic degradation. Quetiapine fumarate was found to degrade significantly in acid, base, and oxidative stress conditions. The degradation products were well resolved from main peak and its impurities. The mass balance was found to be in the range of 96.6–102.2% in all the stressed conditions, thus proved the stability-indicating power of the method. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection and quantification, accuracy, precision, and robustness.
Summary
A rapid, simple and validated reversed-phase high-performance liquid chromatographic method has been developed for analysis of oxaprozin in pharmaceutical dosage forms. Oxaprozin was separated on an ODS analytical column with a 45:55 (v/v) mixture of acetonitrile and triethanolamine solution (5 mm, pH 3.5 ± 0.05, adjusted by addition of 85% phosphoric acid) as mobile phase at a flow rate of 2.0 mL min–1. The effluent was monitored by UV detection at 254 nm. Calibration plots were linear in the range 160 to 240 μg mL–1 and the LOD and LOQ were 14.26 and 41.21 μg mL–1, respectively. The high recovery and low relative standard deviation confirm the suitability of the method for routine QC determination of oxaprozin in tablets.
Abstract
A rapid, stability indicating reverse phase liquid chromatographic method was developed for the determination of purity of Felodipine in active pharmaceutical substance form in the presence of its impurity and its degradation products. To develop the method which is also compatible to liquid chromatographic mass spectroscopic technique. The developed method is also used to determine the assay of Felodipine in bulk drug form. The drug is subjected to various stress conditions like acidic, basic, oxidation, UV light and thermal conditions. Considerable degradation was observed during base hydrolysis. Two degradation products were identified. The Waters Acquity UPLC BEH C18, 2.1 × 100 mm, 1.7 µm Column was used to achieve chromatographic separation. The gradient conditions, diluent and injection volume were optimized to achieve the acceptable resolution between impurities and its degradation products from Felodipine and to get good peak shapes. The masses were determined for main compound and its identified degradation products. Further, the characterization studies for main compound and its degradation products were performed using LCMSMS Q-TOF.
Deltamethrin, a well-known type 2 synthetic pyrethroid insecticide, is a widespread environmental toxicant. It has potential to accumulate in body fluids and tissues due to its lipophilic characteristics. The immune system is among the most sensitive targets regarding toxicity of environmental pollutants. Various methods are available in the literature to analyze deltamethrin (DLM) concentration in plasma and tissues, but regarding the immune organs, only one gas chromatography–tandem mass spectrometry (GC–MS/MS) method (on spleen tissues) has been reported. In the present investigation, a rapid and sensitive high-performance liquid chromatography (HPLC) method has been developed and validated to determine DLM concentration in plasma, thymus, and spleen using zaleplone as an internal standard. Liquid chromatography (LC) separation is performed on an Agilent Zorbax® C8 column (250 mm × 4.6 mm, i.d., 5 μm) with isocratic elution using a mobile phase consisting of acetonitrile–5 mM KH2PO4 (70:30, v/v) at a flow rate of 1 mL min−1. The lower limit of quantification (LLOQ) for DLM is 10 ng mL−1 (plasma, thymus, and spleen). The method has been validated in terms of establishing linearity, specificity, sensitivity, recovery, accuracy, and precision (intra- and inter-day) and stabilities study. This validated method was successfully applied to a pharmacokinetic and tissue distribution study of DLM in mice.
Abstract
The aim of the present study was to find the best extraction parameters to obtain the highest amounts of polyphenols and antioxidants from the walnut. Walnut kernels from ‘Alsószentiváni 117’ cultivar were used for extraction. The extraction methods were as the follows:
Method 1: shaking water-bath at 50 °C for 30 min.
Method 2: shaking water-bath at 50 °C for 30 min, then storing at 5 °C for 20 h.
Method 3: shaking water-bath at 40 °C for 30 min.
Method 4: shaking water-bath at 40 °C for 30 min, then storing at 5 °C for 20 h.
According to our results Method 1 showed the highest FRAP value (34.43 mg AAE g−1), the DPPH value (52,94%) and the highest HPLC peaks for chlorogenic acid, epicatechin and rutin were also seen in extracts obtained using Method 1. TPC values of Method 3 were 26.06 mg GAE g−1 for Method 1 it was 25.65 mg GAE g−1. The results of color values, L* and ΔE* were similar in all extracts as well. In our experiments extraction Method 1 proved to be better than others.
