Ibuprofen piconol is a chemically stable, slightly hygroscopic liquid that strongly partitions into the oil phase and shows no indication of surface activity. This drug has very limited solubility in water (16.5 ppm), modest solubility in glycerol (16.4 mg/mL), and is miscible with less polar organics except for silicone fluids. Varying the initial concentration of ibuprofen piconol does not alter the hydrolysis half-life (concentration range from 50 to 200 μg/mL). The anticoagulant used alters the hydrolysis half-life. For plasma, the half-life is shortest when no anticoagulant is present (t 1/2 =2.5 h) and longer with the presence of anticoagulants; t 1/2 =8.0 h for citrate, t 1/2 =15.5 h for heparin and t 1/2 =161.8 h for EDTA. Red blood cell uptake of ibuprofen piconol is minimal and ranges from 0.4 to 4.1% over the ibuprofen piconol concentrations used in the study.
When ibuprofen piconol is applied topically, only ibuprofen and its metabolites are observed in plasma and urine. The conversion of ibuprofen piconol to ibuprofen appears to be extremely rapid in vivo .