Electrochemical behaviour of tizanidine at solid electrodes.

The electrochemical behaviour of tizanidine [5-chloro(delta-2-imidazolinyl-2-amino)-4-benzothiadiazole-2,1,3], a centrally-active skeletal muscle relaxant has been investigated in aqueous media at the carbon paste electrode (CPE). Cyclic voltammetry at different pH values, controlled potential coulometry and comparative studies on three structurally related molecules have permitted identification of the oxidation site of tizanidine and suggest possible oxidation products in acidic media. The electrochemical reduction at the CPE occurred in one irreversible step and the reduction product (diamine derivative) was detected and characterized on the positive going scan in cyclic voltammetry. Quantitative measurements of tizanidine within the range 2 x 10(-5) M and 1 x 10(-4) M have been realized at the CPE using the differential pulse technique.