Abstract
This paper describes a sensitive, selective, precise, and stability-indicating high performance thin layer chromatographic method for the determination of desvenlafaxine both as a bulk drug and in formulation. The method uses aluminum plates precoated with silica gel 60F-254 as the stationary phase and solvent system ethyl acetate:toluene:methanol:ammonia 7:2:0.5:0.5, (v/v/v/v). This system gave compact spots for desvenlafaxine (0.48 ± 0.06). Desvenlafaxine was subjected to acid and alkali hydrolysis, oxidation, and photodegradation. The peaks of the degradation products were well resolved from that of the pure drug and had significantly different R f values. Densitometric analysis of desvenlafaxine was performed in the absorbance mode at 228 nm. The linear regression analysis data for the calibration plots showed a good linear relationship over concentration range of 100–1000 ng · spot−1. The mean values of the correlation coefficient, slope, and intercept were 0.9997 ± 0.04, 7.4521 ± 0.437, and 781.15 ± 0.51, respectively. The method was validated for precision, robustness, and recovery. The limit of detection and limit of quantitation were 10 and 100 ng · spot−1, respectively. Statistical analysis showed that the method is repeatable, selective, and can separate the drug from its degradation products and can be used to monitor stability.
ACKNOWLEDGMENT
The authors thank Dr. Reddy's Laboratories Ltd. (Hyderabad, Andhra Pradesh, India) for providing the gift sample of standard desvenlafaxine and Dr. K. R. Mahadik, Principal, Poona College of Pharmacy, Pune, India, for providing necessary facilities to carry out the work.
Notes
a n = 6.
b Average of three concentrations 100, 400, and 1000 ng · spot−1.
a n = 6.