Method validation for metronidazole analysis by HPLC in extemporaneous suspensions

Abstract

Introduction: Extemporaneous metronidazole suspensions are consistently prepared at Sapphasitthiprasong hospital in Ubon Ratchathani province. In order to obtain the exact amount of metronidazole, the method of such drug has to be efficiently proved. The main objective of this present research was to validate the method for analyzing metronidazole oral suspensions with the dose of metronidazole 50 mg per mL by using high performance liquid chromatography (HPLC). Methods: The study of method validation for extemporaneous metronidazole suspensions was included in the topics of linearity, precision, limit of detection (LOD), limit of quantification (LOQ) and accuracy. This method validation finally based on the assay of metronidazole tablet from USP 36 NF 31 and such method was evaluated via HPLC. The operating system was obtained under the following HPLC conditions: the mobile phase composition of water : methanol in 80 : 20, flow rate of 1 mL/min, volume of injection at 10 μL, HPLC column C18 150 x 4.6 mm containing particle size 5.0 μm. All samples were analyzed using UV detector at the wavelength of 254 nm. Results: According to the study of method validation, the r-square of linearity is more than 0.9990 with the range of the concentration 5 v 25 μg/mL. The precision results shown in the percentage of the relative standard deviation (%RSD) were less than 2 in both intraday and interday. From the data of analytical chemistry, the LOD and LOQ can be detected at 0.0081 μg/mL and 0.2460 μg/mL, respectively. Moreover, the accuracy data which are shown in the %recovery of metronidazole, were still in the range of 80 v 120%. Conclusion: The proposed method met the general requirement for validation. It was accurate and reliable and was able to act as a stability-indicating method for the determination of metronidazole in the extemporaneous suspensions.