Chromatographic method for dacarbazine quantification in skin permeation experiments.

Dacarbazine (DTIC) is a chemotherapeutic drug currently used for the systemic treatment of melanomas. Considering the easy access to these tumors, a topical route of drug administration could provide a more comfortable and less toxic treatment. However, DTIC quantification aiming at the design of topical formulations is challenging, pondering all the interferents present in the drug samples recovered from the skin. Hence, this work intended to validate a selective chromatographic method for DTIC determination in skin permeation studies. A reversed-phase C 18 column was used as a stationary phase, and gradient elution of a mobile phase consisting of methanol and pH 6.5 sodium phosphate monohydrate buffer (0.01 mol/L) at a flow rate of 1.0 mL/min was implemented. DTIC was detected at 364 nm. The method was selective against skin interferents, linear (r = 0.9995) in a concentration range of 1.0–15.0 μg/mL, precise with an overall variation coefficient lower than 3.8%, accurate achieving recovery from the skin layers within 91–112%, and sensitive for the proposed application (detection limit = 0.10 μg/ mL, quantification limit = 0.30 μg/mL). Furthermore, the analytical method was successfully tested in in vitro skin permeation studies. In conclusion, the developed method is appropriate for DTIC analysis from the skin sample matrix. • HPLC method for dacarbazine determination in skin samples to be used in permeation studies. • The method was selective against skin interferents, with linearity, precision, and accuracy. • The method also showed high recovery capacity of dacarbazine from skin matrices. • The analytical method complies with the international validation guidelines of ICH and FDA. [ABSTRACT FROM AUTHOR]