Resumen de Kinetic spectrophotometry method for the determination of morphine, nalbuphine and naltrexone drugs in bulk and pharmaceutical formulations
Akram M El-didamony, Monir Z Saad, Nora O Saleem
A novel study describes the development and validation of a selective and simple kinetic spectrophotometric method for the determination of some analgesic drugs namely, morphine (MOF), nalbuphine (NAB) and naltrexone (NAT) in bulk and in pharmaceutical formulations. This method was based on the reaction of the drugs under studying with alkaline KMnO4 to form a water-soluble bluish green colored product with a maximum absorbance at 605 nm. Although, the determination of MOF, NAB and NAT drugs by rate constant, fixed-concentration and fixed time methods were feasible with the calibration equations obtained, the fixed time method has been found to be more applicable. The fixed-time method is adopted for constructing the calibration curves, which were found to be linear over the concentration ranges of 4 - 18 μg mL-1 MOF, 2 - 20 μg mL-1 NAB and 2 - 16 μg mL-1 NAT. Different experimental parameters which can affect the development and stability of the color were carefully studied and optimized. The fixed time method of 20 min was further applied to pharmaceutical formulations of each drug and the percentage recoveries were 99.85±0.049 to 102.27±0.024. Statistical comparisons of the results with the reference methods show the excellent agreement and indicate no significant difference in accuracy and precision.
