Removal of erdosteine active substance from wastewater by chitosan/PVA and determination of the remaining erdosteine quantity by a new HPLC method

In this study, it was aimed to develop HPLC methods for the determination of erdosteine in standard working

solutions and tablets. In addition, it was aimed to determine adsorption rates depending on time by using

chitosan/pva adsorbents for the removal of erdosteine in wastewater by the developed HPLC method.

In the HPLC method developed in this study, the C18 (Zorbax; 150 x 4.6 mm, 5 μm) column uses a mobile

phase consisting of methanol-water (0.01 M Acetic acid; 65:35, V:V). Operating parameters consisting of a

flow rate of 0.4 mL/min, a wavelength of 235 nm and an injection volume of 5 μL were used. While

determining these parameters, firstly the data in the literature were examined and thus the most appropriate

parameters were determined. It was determined that the method was linear in the concentration range of

0.1-25 μg/mL. A series of standard erdosteine solutions were prepared from the stock solution at

concentrations of 0.1, 0.5, 1, 5, 10 and 25 μg/mL and their chromatograms were taken on HPLC. Chitosan/pva

were used as adsorbents for erdosteine removal from wastewater. Accordingly, the adsorption process was

carried out for 5, 10, 20, 40 and 80 min depending on the time. Afterwards, the amount of erdosteine in the

obtained solutions was determined by HPLC. Results: A calibration curve was obtained by plotting the

erdosteine peak area against the concentration of each solution. From the regression analysis of the

calibration curve, the equation of the regression line is y = 14.33x + 0.6505; The correlation coefficient (r) for

the active substance erdosteine was determined as 0.9995. The LOD value of the method is determined as

0,03 and the LOQ value is 0.01. Intraday accuracy and precision studies, %BH and %BSS were determined to

be 6.5% and 0.387%, respectively. The recovery values of the method, for which validity tests were

performed, were found to be 99.8% with the application of erdostin capsules containing erdosteine. In the

adsorption process, 5.67, 11.47, 32.22, 76.25 and 76.8 percent erdosteine removal was achieved in 5-80

minutes, respectively. Accordingly, the highest adsorption percentage was reached at 76.8 at the end of 80

minutes.

In studies carried out with HPLC, the quantification of the active substance erdosteine in commercial

preparations was successfully carried out, and these methods were developed and validity tested. It was

concluded that the methods can be successfully applied in studies for quality control purposes in

pharmaceutical preparations, since validation studies have shown that the methods are sensitive, sensitive,

selective, accurate and precise. It has also been determined that this method can be used for post-adsorption

quantification.