A Validated Rapid Stability-Indicating Method for the Determination of Related Substances in Vardenafil Hydrochloride by Ultra-Performance Liquid Chromatography

Kishore Kumar Kakumani, Kameswara Rao Chimalakonda, Rama Koti Reddy Yarram, Mukkanti Khagga

.

DOI: 10.4236/ajac.2012.31009                

Abstract

A novel, sensitive, stability indicating RP-LC method has been developed for the quantitative determination of Varde- nafil and its related impurities in both bulk drugs and Pharmaceutical dosage forms. Effective chromatographic separation was achieved on a C18 stationary phase with simple mobile phase combination delivered in a simple gradient pro- gramme and quantitation was by ultraviolet detection at 210 nm. The mobile phase consisted of a buffer and acetonitrile delivered at a flow rate 0.25 ml?min–1. Buffer consisted of 20 mM Ammonium bi carbonate, pH adjusted to 5.0 by using ortho Phosphoric acid. In the developed UPLC method the resolution (Rs) between vardenafil and its four potential impurities was found to be grater than 2.0.Regrreation analysis showed an r value (correlation coefficient) grater than 0.999 for vardenafil and its four impurities. This method was capable to detect all four impurities of vardenafil at a level of 0.25 μg.mL–1 with respect to test concentration of 500 μg?ml–1 for a 2 μl injection volume. The inter and intra day precision values for all four impurities and for vardenafil was found to be with in 2.0% RSD. The method showed good and consistent recoveries for vardenafil in bulk drugs (98.8% - 100.9%), pharmaceutical dosage forms (100.5% - 101.5%) and its all four impurities (99.8% - 102.5%).The test solutions was found to stable in acetonitrile for 48 h. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis, and thermal degradation. Considerable degradation was found to occur in peroxide hydrolysis. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.9%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness.

Keywords

Vardenafil; Validation; Impurities and Degradation Products

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	M. Bakshi and S. Singh, “Development of Validated Stabil-ity-Indicating Assay Methods—Critical Review,” Jour- nal of Pharmaceutical and Biomedical Analysis, Vol. 28, No. 6, 2002, pp. 1011-1040. doi:10.1016/S0731-7085 (02)00047-X
[2]	USP D1, “Drug Information for the Health Care Professional,” 25th Edition, The United State Pharmcopeial Convention Inc., Rockville, 2005.
[3]	Mosby, “Mosby’s Pediatric Drug Consult’s Drug Consult,” 15th Edition, Elsevier Inc., New York, 2005.
[4]	E. Wespes, E. Amar, D. Hatzichristou, F. Montorsi, J. Pryor and Y. Vardi, “Guidelines on Erectile Dysfunction,” European Urology, Vol. 41, No. 1, 2002, pp. 1-5 doi:10.1016/S0302-2838(01)00008-2
[5]	C. G. Stief, S. Uck-ert, A. J. Becker, M. C. Truss and U. Jonas, “The Effect of the Specific Phosphodiesterase (Pde) Inhibitors on Human and Rabbit Cavernous Tissue in Vitro and in Vivo,” Journal of Urology, Vol. 159, No. 4, 1998, pp. 1390-1396.
[6]	J. C. Reepmeyer and J. T. Woorruff, “Use of Liquid Chromatogra-phy—Mass Spectrometry and a Hydrolytic Technique for the Detection and structure Elucidation of a Novel Synthetic Vardenafil Designer Drug Added Illegally to a “Natural” Herbal Dietary Supplement,” Journal of Chromatography A, Vol. 1125, No. 1, 2006, pp. 67-75. doi:10.1016/j.chroma.2006.05.018
[7]	P. Zou, S. S.-Y. Oh, P. Hou, M.-Y. Low and H.-L. Koh “Simultaneous Determination of Synthetic Phosphodiesterase-5 Inhibitors Found in a Dietary Supplement and Pre-Mixed Bulk Powders for Dietary Supple-ments Using High-Performance Liquid Chromatography with Diode Array Detection and Liquid Chromatography-Electro- spray Ionization Tandem Mass Spectrometry,” Journal of Chromatography A, Vol. 1104, No. 1-2, 2006, pp. 113- 122. doi:10.1016/j.chroma.2005.11.103
[8]	X. Zhu, S. Xiao, B. Chen, F. Zhang, S. Yao, Z. Qan, et al. “Simultaneous Determi-nation of Sildenafil, Vardenafil and Tadalafil as Forbidden Components in Natural Dietary Supplements for Male Sexual Potency by High-Per- formance Liquid Chromatogra-phy-Electrospray Ionization Mass Spectrometry,” Journal of Chromatography A, Vol. 1066, No. 1-2, 2005, pp. 89-95. doi:10.1016/j.chroma.2005.01.038
[9]	F. J. Rodriguez, J. J. B. Nevado, P. G. Castaneda and D. N. Mora, “Development of a Micellar Electrokinetic Capillary Chromatography Method for the Determination of Three Drugs Employed in the Erectile Dysfunction Therapy,” Journal of Chromatography B, Vol. 811, No. 2, 2004, pp. 231-236.
[10]	S. R. Gratz, C. L. Flurer, K. A. Wolnik, “Analysis of Undeclared Synthetic Phosphodiesterase-5 Inhibitors in Dietary Supplements and Herbal Matrices by LC-ESI-MS and LC-UV,” Journal of Pharmaceutical and Biomedical Analysis, Vol. 36, No. 3, 2004, pp. 525-533. doi:10.1016/j.jpba.2004.07.004
[11]	Stability ICH, “Testing of New Drug Substances and Products Q1A (R2),” International Conference on Harmonization, IFPMA, Geneva, 2003.
[12]	ICH Photo Stability, “Testing of New Drug Sub-stances and Products Q1b,” International Conference on Har-monization, IFPMA, Geneva, 1996.
[13]	S. Singh, B. Singh, R. Bahuguna, L. Wadhwa and R. Saxena “Stress Degradation Studies on Ezetimibe and Development of a Validated Stabili-ty-Indicating HPLC assay,” Journal of Pharmaceutical and Biomedical Ana- lysis, Vol. 41, 2006, pp. 1037-1040. doi:10.1016/j.jpba.2006.01.030
[14]	Drug Stability Principles and Practices, 3rd Edition, T. Carstensen and C. T. Rhodes, Eds., Marcel Dekker, New York, 2000.
[15]	R. Rajagopalan, “Review of Regulatory Guidance on Impurities,” Separation Science and Technology, Vol. 5, 2004, pp. 27-37.
[16]	ICH Guidelines Q2(R1), Validation of Analytical Procedures, Geneva, 2005.