Spectrophotometric Study and Determination of Ibuprofen and Lornoxicam Drugs via Their Reaction with Copper (II) Reagent and Their Biological Activities

Abstract

The reactions of Ibuprofen (IBU) and Lornoxicam (LOR) drugs with copper tetramine and copper sulphate reagents respectively were studied spectrophotometrically at optimum conditions of, reactant concentration, temperature, time, λmax and pH. Applying of molar ratio method (MRM) on the Ibuprofen and Lornoxicam copper ion-pairs, indicated (1:1) stoichiometric ratio. In addition, validity of Beer's Law was carried out at 265 and 260 nm, for Ibuprofen and Lornoxicam products, respectively. Results of analysis were statistically validated. The linearity ranged from 2.063 to 103.14 and 3.72 to 74.36 μg ml-1 of recovery values 99.95 to 100.40 and 99.98 to 100.00 %, for IBU and LOR respectively. The low values of standard deviation (SD = 0.009 to 0.533 and 0.059 to 0.844) and relative standard deviation (RSD = 0.037 to 0.577 and 0.063 to 0.635 %) refer to the accuracy and precision of the proposed method for spectrophotometric micro-determination of these drugs in pure and in their pharmaceutical formulations in comparison with official methods. The robustness and procedure validation were assayed in intra and inter days. The solid ion-pairs of these drugs with copper have been separated and identified by elemental analyses and FT-IR spectroscopic tool and they were found to be biologically active toward some kinds of Tribolium confusum common insect species in flour mills and treated areas and their adults. These ion-pairs were found to be more biologically active than their drugs.