Author(s)

Alejandra Toledo López¹, Hugo Juárez Olguín^1*, Ismael Lares-Asseff², Fernanda Reyes González¹, Radames Alemon Medina¹, Gabriela Pérez Guillé¹, Francisca Trujillo Jimenez¹

¹Laboratory of Pharmacology, Instituto Nacional de Pediatría, Mexico City, Mexico.
²Centro de Investigación Interdisciplinario para el Desarrollo Integral Regional, Durango, Mexico.

Aim: To develop a simple and sensitive high-performance liquid chromatography method to determine plasmatic levels of trimethoprim/sulfamethoxazole in paediatric population. Method: Chromatographic separation was carried out using a reverse phase column with detection ultraviolet at a wavelength of 225 nm. The mobile phase consists of phosphate buffer 0.1 M, acetonitrile and methanol, (65:20:15) with a flow of 1.0 ml/min. Results: Calibration curve was linear over the concentration range for trimethoprim of 0.25 to 5 μg/ml and 5 to 100 μg/ml for sulfamethoxazole. Precision were found to be within 15% for both compounds. The detection limits and quantifications for trimethoprim/sulfamethoxazole were 0.2 - 0.25 μg/ml and 3 - 5 μg/ml respectively. Conclusions: The developed method was applied for the quantification of both compounds in plasma samples of two patients resulting concentrations within the therapeutic ranges. The method is convenient for pharmacokinetic studies.

Children, Liquid Chromatography, Phase Reverse, Pharmacokinetics

López, A. , Olguín, H. , Lares-Asseff, I. , González, F. , Medina, R. , Guillé, G. and Jimenez, F. (2019) A Reliable Method to Quantify Trimethoprim and Sulfamethoxazole in Plasma of Children by HPLC with Application in Pharmacokinetic Studies. American Journal of Analytical Chemistry, 10, 247-253. doi: 10.4236/ajac.2019.107019.