A low cost method for carbamazepine, ciprofloxacin and norfloxacin determination in pharmaceutical formulations based on spot-test and smartphone images

Abstract

The use of digital image-based method to determine several compounds has been applied in the different fields of sciences and health area. Antibiotics and antiepileptics are used worldwide and require a strict monitoring. High cost methods using chromatographic techniques are commonly applied to the quality control of those pharmaceutical compounds. Therefore, the present study aims to present a simple and precise method to determine carbamazepine, ciprofloxacin and norfloxacin in pharmaceutical formulations using low-cost devices and digital images obtained by smartphone. Spot-tests and a box to capture the digital images were made in a 3D printer. The images were processed in the RGB system by Image J software to obtain the RGB channels signal values as analytical signal. The smartphone enabled quick and in situ analyzes, a limit of detection of 3.0, 1.0 and 1.0 mg L−1 and limit of quantification of 5.0, 3.0 and 3.0 mg L−1 were obtained for carbamazepine (CBZ), ciprofloxacin (CIP) and norfloxacin (NOR), respectively. The intra-day precision (RSD %) varied from 0.590 to 19.5 %. The developed method was compared to a method using spectrophotometry, and the results obtained by both methods were statistically equal. The proposed method allowed rapid analyzes, of about 16 s, low samples and chemical volume were required (8 µL), and a total cost of U$ 2.00. The developed method presents a new analytical tool, environmental friendly, portable and useful for labs with limited resources.