Winnonlin professional software version 6

OPS-2071 was orally administered at 2 mg/kg to male Syrian hamsters, and the cecal contents were collected 0.5, 1, 2, 4, 8, 24, 48, and 72 h postdose (n = 5 for each time point). After homogenizing with saline and treatment using acetonitrile-formic acid (100:1 [vol/vol]), the OPS-2071 concentration in cecal contents was determined using a validated liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method. The mass spectrometer 4000 QTRAP (AB Sciex Pte. Ltd.) and high-performance liquid chromatography Prominence UFLC system (Shimadzu Corp.) were used. The pharmacokinetic (PK) parameters (Cmax) were determined with WinNonlin professional software version 6.3, (Pharsight Corp.).

PK parameters were determined for each matrix by noncompartmental analysis using mean concentration values (right eyes, left eyes, and all eyes) for each matrix. Concentration and parameter values were rounded to two decimals, and coefficient of variation was rounded to one decimal.
PK analyses included determination of the maximum observed concentration (C_max), the time to C_max (t_max), and the area under the concentration–time curve (AUC_t) from time 0 to the last measurable time point. PK analysis was performed using validated WinNonlin^® Professional software, version 6.3, integrated in the Phoenix^® Suite, version 1.3 (Pharsight Corporation, Mountain View, CA, USA).
Arithmetic mean concentrations were calculated only when n ≥ 3 and at least two numerical values were above the lower limit of quantification (LLOQ). Concentration values below the LLOQ or no peak were treated as zero.