Effect of PVP K30 and/or l-Arginine on Stability Constant of Etoricoxib–HPβCD Inclusion Complex: Preparation and Characterization of Etoricoxib–HPβCD Binary System

Abstract

The effect of polyvinyl pyrrolidone (PVP) K30 and/or l-arginine on etoricoxib–HPβCD complex was investigated. The phase solubility profiles were classified as A_L-type, both in absence or presence of auxiliary substances used. The apparent stability constant (K_c) of binary complex obtained at room temperature, 371.80 ± 2.61 M⁻¹, was decreased with the addition of PVP and arginine indicating no benefit of addition of auxiliary substances to promote higher complexation efficiency. Therefore, solid etoricoxib–HPβCD binary systems were prepared and characterized by proton nuclear magnetic resonance spectroscopy (¹HNMR), X-ray powder diffractometry, Fourier transformation-infrared spectroscopy, and dissolution studies. Among all binary systems, a lyophilized product showed superior performance in enhancing dissolution of etoricoxib.

Keywords:

• etoricoxib
• HPβCD
• stability constant
• phase solubility
• ¹HNMR
• dissolution rate

ACKNOWLEDGMENTS

The authors are thankful to Shivaji University, Kolhapur, Maharashtra, India for providing XRD facility and to Pune University, Pune, Maharashtra, India for providing FTIR, and NMR facilities, respectively. The authors are very much thankful to Principal, Government College of Pharmacy, Karad, Maharashtra, India for providing laboratory facilities and constant encouragement.