Comparison of pharmacokinetics and safety characteristics between two olopatadine hydrochloride 5 mg tablet formulations in healthy Korean subjects

Histamine acts by binding to four histamine receptors (H1 to H4), of which the H1 is known to participate in dilate blood vessels, bronchoconstriction, and pruritus. Olopatadine hydrochloride blocks the release of histamine from mast cells and it inhibits H1 receptor activation. Olopatadine hydrochloride is anti-allergic agent that is effectively used. The object of this study had conducted to compare the pharmacokinetics (PKs) and safety characteristics between olopatadine hydrochloride 5 mg (test formulation) and olopatadine hydrochloride 5 mg (reference formulation; Alerac (R)) in Korean subjects. This study had conducted an open-label, randomized, fasting condition, single- dose, 2-treatment, 2-period, 2-way crossover. Subjects received single-dosing of reference formulation or test formulation in each period and blood samples were collected over 24 hours after administration for PK analysis. A wash-out period of 7 days was placed between the doses. Plasma concentration of olopatadine were determined using liquid chromatography-tandem spectrometry mass (LC-MS/MS). A total of 32 subjects were enrolled and 28 subjects completed. There were not clinical significantly different in the safety between two treatment groups for 32 subjects who administered the study drug more than once. The geometric mean ratio of test formulation to reference formulation and its 90% confidence intervals for The peak plasma concentration (C-max) and the areas under the plasma concentration-time curve from 0 to the last concentration (AUC(last)) were 1.0845 (1.0107-1.1637) and 1.0220 (1.0005-1.0439), respectively. Therefore, the test formulation was bioequivalent in PK characteristics and was equally safe as the reference formulation.