scholarly journals The influence of pH and temperature on the stability of flutamide. An HPLC investigation and identification of the degradation product by EI+-MS

RSC Advances ◽  
2015 ◽  
Vol 5 (5) ◽  
pp. 3206-3214 ◽  
Author(s):  
R. N. El-Shaheny ◽  
K. Yamada

Stability of flutamide was investigated using validated stability-indicating HPLC method. Degradation kinetics, Arrhenius plots, and pH-rate profile curve were explored.

2013 ◽  
Vol 63 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Atul Awasthi ◽  
Majid Razzak ◽  
Raida Al-Kassas ◽  
Joanne Harvey ◽  
Sanjay Garg

The aim of this study was to evaluate stability characteristics and kinetics behavior of abamectin (ABM) as a 1 % (m/V) topical veterinary solution. During the study, samples stressed at 55 and 70 °C were regularly analyzed for several parameters over 8 weeks on a chromatographic (HPLC) system, using a Prodigy C18, 250 x 4.6 mm, 5-μm, column eluting with 15 : 34 : 51 (V/V/V) water/methanol/ acetonitrile as mobile phase. The HPLC method was validated for precision, accuracy, linearity and specificity, and was found to be stability indicating. The results showed that degradation of ABM followed first-order kinetics and data on loss in kobs (s-1) and half life (t1/2, days) demonstrated ABM showing the maximum stability in glycerol formal. The degradation behavior of ABM varies from solvent to solvent. The effect of added alkali on pH change and loss of ABM was studied and found to be unique for all solvents and very distinct from typical hydrolysis degradation. The present study may serve as a platform to design and develop topical non-aqueous solutions of ABM for veterinary use given no such comprehensive efforts have been published to date on the stability profile of ABM in non-aqueous solvents.


Author(s):  
Vaishali Mistry ◽  
Rohan Mishra

Objective: This study describes the stability-indicating reverse-phase high-performance liquid chromatography (RP-HPLC) method for simultaneous estimation of betahistine dihydrochloride and domperidone in pharmaceutical dosage forms.Methods: The proposed RP-HPLC method was developed using Shimadzu Prominence-i LC-2030 HPLC system equipped with UV detector and chromatographic operation was carried on Shim-pack C18 (250 mm×4.6 mm, 5 μ) column at a flow rate of 1 ml/min and the run time was 10 min. The mobile phase consisted of methanol and water in the ratio of 80:20% v/v and eluents were scanned using a UV detector at 244 nm.Results: The retention time of betahistine dihydrochloride and domperidone was found to be 2.3 and 3.6 min, respectively. A linearity response was observed in the concentration range of 9.6 μg/ml–22.4 μg/ml for betahistine dihydrochloride and 6–14 μg/ml for domperidone, respectively. Limit of detection and limit of quantification for betahistine dihydrochloride were 0.52 μg/ml and 1.58 μg/ml and for domperidone are 0.64 μg/ml and 1.94 μg/ml, respectively.Conclusion: The stability-indicating method was developed by subjecting drugs to stress conditions such as acid and base hydrolysis, oxidation, photo and thermal degradation, and degraded products formed were resolved successfully from samples.


2020 ◽  
Vol 4 (1) ◽  
pp. 12-17
Author(s):  
Fábio Barbosa ◽  
Leonardo Pezzi ◽  
Julia Sorrentino ◽  
Martin Steppe ◽  
Nadia Volpato ◽  
...  

Stability studies correspond to a set of tests designed to assess changes in the quality of a given drug over time and under the influence of a number of factors. Among these factors, pH plays an important role, due to the catalytic effect that hydronium and hydroxide ions can play in several reactions. In the present study, the degradation kinetics of nitazoxanide was evaluated over a wide pH range, and the main degradation product generated was identified by LC-MS/MS. Nitazoxanide showed first-order degradation kinetics in the pH range of 0.01 to 10.0 showing greater stability between pH 1.0 and 4.0. The degradation rate constant calculated for these pH was 0.0885 x 10-2 min-1 and 0.0689 x 10-2 min-1, respectively. The highest degradation rate constant value was observed at pH 10.0 (0.7418 x 10-2 min-1) followed by pH 0.01 (0.5882 x 10-2 min-1). A major degradation product (DP-1) was observed in all conditions tested. Through LC-MS/MS analysis, DP-1 was identified as a product of nitazoxanide deacetylation. The effect of pH on the stability of nitazoxanide and the kinetic data obtained contribute to a better understanding of the intrinsic stability characteristics of nitazoxanide.


INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (01) ◽  
pp. 20-27
Author(s):  
Sandeep S. Sonawane ◽  
◽  
Akshay S. Patil ◽  
Santosh S. Chhajed ◽  
Dimple S. Lalchandani ◽  
...  

A simple, accurate, reproducible and specific stability-indicating RP-HPLC method was developed for estimation of ethionamide in tablets. Ethionamide was exposed to acid, alkali and neutral hydrolysis at elevated temperatures, to thermolytic degradation, peroxide-mediated oxidation at room temperature in dark and to photolytic degradation. The drug was found stable to thermolytic and photolytic conditions and to neutral hydrolysis. However, substantial degradation was obtained in acid and alkali hydrolysis and complete degradation in peroxide-medicated oxidation. Similar degradation behavior was observed when ethionamide tablets were exposed to the mentioned forced degradation conditions. The method showed adequate resolution of drug from its potential degradation products on C18 (250 × 4.6 mm, 5µ) column using mobile phase of methanol: water (50: 50 % V/V) at 1 mL/min. The drug and its potential degradation products were detected at 290 nm. The method was validated as per the ICH Q2(R1) guidelines. The enrichment of the alkali degradation product was performed and isolated by preparative TLC and further confirmed by NMR and IR spectroscopy.


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