Abstract

Determination of oxybuprocaine HCL in pharmaceutical formulations using thermal techniques

Author(s): Hanan A.Merey, Fahima A.Morsy, Mohammed A.Mohammed, Maissa Y.Salem

The thermal behavior of oxybuprocaine hydrochloride (OXY) has been studied. Thermogravimetric analysis (TGA), derivative thermogravimetry (DTG) and differential thermal analysis (DTA) techniques were used to study the thermal behavior of the drug. Thermal-analytical study showed that OXY is thermally decomposed in four steps. The first step occurs in the temperature range of 62.05- 166.70 ºC, the second step occurs at 166.70 -354.91 ºC, the third step occurs at 354.91 - 455.52 ºC and the fourth step at 455.52–489.05 ºC. Melting point of OXP was recorded at 160.15 ºC. Thermodynamic parameters such as activation energy (Ea), frequency factor (A), reaction order (n), and correlation coefficient (r) were calculated using different kinetic models. The purity value for the drug was found to be 99.36%. Thermal analysis technique gave satisfactory results to obtain quality control parameters such as melting point, water content and ash content in comparison to those obtained using official methods. Thermal analysis justifies its application in quality control of pharmaceutical compounds due to its simplicity, sensitivity and low operational costs. DSC results indicated that the degree of purity of Oxybuprocaine HCl is similar to that found by official method.