Mohammed Alarjah* Pages 738 - 747 ( 10 )
Background: Prodrugs principle is widely used to improve the pharmacological and pharmacokinetic properties of some active drugs. Much effort was made to develop metronidazole prodrugs to enhance antibacterial activity and/or to improve pharmacokinetic properties of the molecule or to lower the adverse effects of metronidazole.
Objective: In this work, the pharmacokinetic properties of some of monoterpenes and eugenol pro metronidazole molecules that were developed earlier were evaluated in vitro. The kinetic hydrolysis rate constants and half-life time estimation of the new metronidazole derivatives were calculated using the validated RP-HPLC method.
Methods: Chromatographic analysis was performed using Zorbbax Eclipse eXtra Dense Bonding (XDB)-C18 column of dimensions (250 mm, 4.6 mm, 5 μm), at ambient column temperature. The mobile phase was a mixture of sodium dihydrogen phosphate buffer of pH 4.5 and methanol in gradient elution, at 1ml/min flow rate. The method was fully validated according to the International Council for Harmonization (ICH) guidelines. The hydrolysis process was carried out in an acidic buffer pH 1.2 and in an alkaline buffer pH 7.4 in a thermostatic bath at 37 ºC.
Results: The results followed pseudo-first-order kinetics. All metronidazole prodrugs were stable in the acidic pH, while they were hydrolysed in the alkaline buffer within a few hours (6-8 hr). The rate constant and half-life values were calculated, and their values were found to be 0.082- 0.117 hr-1 and 5.9- 8.5 hr., respectively.
Conclusion: The developed method was accurate, sensitive, and selective for the prodrugs. For most of the prodrugs, the hydrolysis followed pseudo-first-order kinetics; the method might be utilised to conduct an in vivo study for the metronidazole derivatives with monoterpenes and eugenol.
Metronidazole prodrugs, hydrolysis rate constant, RP-HPLC-DAD 10X sensitive, in vitro evaluation, carvacrol, eugenol.
Department of Pharmaceutical Chemistry, College of Pharmacy, Umm Alqura Univeristy – Alabdiah, Alawali-Macca