Green Spectrophotometric Methods for the Determination of Ivermectin and Closantel in Veterinary Dosage Forms

Closaverm® is an injectable solution for cattle and sheep, containing 125.0 mg of closantel and 5.0 mg of ivermectin. It is effective against parasitic infestations and liver flukes. Spectrophotometric techniques were used to determine closantel and ivermectin in bulk powder and veterinary dosage forms. The techniques employed in this study consisted of univariate spectrophotometric methods that relied on mathematical calculations or graphical representations of data. Ivermectin was determined using several methods, including ratio subtraction, constant value, concentration value as well as constant multiplication followed by spectrum subtraction, while closantel was determined using the zero-order method. Three green analytical evaluation approaches were used to perform a quantitative and qualitative green performance evaluation of the suggested methods, namely the National Environmental Method Index, the Analytical Eco-Scale, and the Analytical GREEnness Metric tool. Different spectrophotometric methods were utilized to analyze the combination present in the veterinary dosage form of Closaverm®, with a linearity range of 8.0–75.0 µg/mL for closantel and 3.0–26.0 µg/mL for ivermectin. The suggested green analytical methods are eco-friendly and straightforward, providing an appropriate alternative for routine analysis of the mixture in quality control laboratories. The results obtained are precise and require minimal manipulation steps, thereby reducing the potential for errors and the time required for analysis. Additionally, these methods pose no adverse impacts on the health of the analyst or the environment. This study marks the first instance of a spectrophotometric method being utilized to determine the combination of ivermectin and closantel. The developed techniques exhibit exceptional green quality while upholding analytical standards.