Rapid high-performance liquid chromatographic assay of dorzolamide in rabbit aqueous humor

A rapid high-performance liquid chromatographic method using a C(18) reversed-phase column (Hypersil ODS) with UV detection at 254 nm and a simple pre-treatment of samples is presented for the analysis of dorzolamide, a carbonic anhydrase inhibitor, in rabbit aqueous humor. A water solution containing 2% ZnSO(4) small middle dot7H(2)O was used to deproteinize aqueous humor samples. The mobile phase consisted of 7% CH(3)CN and 93% of a solution containing 1% TEA adjusted to pH = 3.5 with H(3)PO(4). Paracetamol was found to be a suitable internal standard. The standard curves were linear in the detection range. The precision and the accuracy were <5% for both intra- and inter-day assays.