A new and ecological miniaturized method by spectrophotometry for quantification of vancomycin in dosage form

Abstract

Vancomycin, an important antibiotic, is marketed as lyophilized powder. In the context of routine analysis of this product, the existence of a more advantageous and effective method is interesting. Thus, the objective of this work is to develop and validate a new analytical method, faster, low-cost, ecological and miniaturized for quantification of vancomycin in lyophilized powder using spectrophotometry in ultraviolet region. Buffer solution pH 6.8, quartz cuvette with capacity of 700 µL and 280 nm were chosen. The method proved to be linear in the range of 50-150 µg/mL (0.9997). The selectivity of the method was proven in two ways: The standard-sample overlay aimed to identify vancomycin in the sample; The forced degradation test (sample solutions prepared in 0.01 M HCl, 0.01 M NaOH and aqueous conditions and kept at 60 ºC by 8 hours, and UV 254 nm at ambient temperature during 24 hours) aimed to show the susceptibility of the method to consequently indicate the stability of the sample. It was precise in intraday (RSD 1.27%), interday (RSD 1.18%) and between analysts (RSD 1.92%) levels. It was robust when small variations were performed in seven important parameters (wavelength, cuvette, filtration step, dibasic and monobasic phosphate brand, ultrasound time and source of water). The accuracy was proved by the standard recovery test and showed mean recovery of 101.10%. This method can be applied in routine analysis of quality control of vancomycin lyophilized powder and it is an effective, accessible and ecological alternative, which follows the Green Analytical Chemistry principles, presenting less waste generation, no use of toxic solvents, smaller sample volumes and required diluents, which impacts on the final cost of the analyzes.