Development, Optimization, and Validation of a Green and Stability-Indicating HPLC Method for Determination of Daptomycin in Lyophilized Powder

Daptomycin is an antimicrobial that plays an important role in clinical practice today because it is considered a promising drug to combat resistant strains, such as methicilin and vancomycin-resistant Gram-positive bacteria. Considering the analysis of daptomycin in a pharmaceutical dosage form, the only method found in literature uses potentially toxic organic solvents. Therefore, the objective of this work was to develop a green and stability-indicating HPLC method for determination of daptomycin in lyophilized powder. The mobile phase was ethanol-water (55+45, v/v) at pH 4.5 pumped at a flow rate of 0.6 mL/min. A C18 column was used, and UV detection was performed at 221 nm. Stress degradation studies were conducted in order to demonstrate the specificity and stability-indicating capability of the method. The method was validated according to International Conference on Harmonization guidelines, proving to be linear (r=0.9996), precise, accurate, robust (demonstrated by the Plackett-Burman model), and specific within the range 20-70 μg/mL. The retention time of daptomycin was 5.8 min. It can be concluded that the validated method can be a fast, safe, and environmentally friendly alternative for the analysis of daptomycin.