Acetylcysteine lysinate

Rapid onset of analgesic action is linked with rapid absorption of analgesics (high maximum concentration [Cmax] and short time to maximum concentration [tmax]). After overnight fasting, ibuprofen lysinate reaches higher peak plasma levels (Cmax) earlier than ibuprofen acid (tmax) with comparable exposure (area under the plasma concentration–time curve [AUC]); however, subjects usually take ibuprofen with or within a short time of a meal. Therefore, pharmacokinetic (PK) studies under fed conditions may better characterize properties under real‐life conditions. We investigated a new fixed‐dose combination (FDC) of ibuprofen acid 400 mg and caffeine 100 mg in 2 single‐dose, randomized, crossover PK studies in healthy subjects (both N = 36). The FDC was compared with ibuprofen 400 mg as acid and as lysinate after an overnight fast in Study 1, and with ibuprofen lysinate after a meal in Study 2. After fasting, results for ibuprofen in the FDC were comparable with those from ibuprofen acid alone. Caffeine did not affect the Cmax, tmax, and AUC. As expected, a higher Cmax and shorter tmax were observed with ibuprofen lysinates vs the FDC. Compared with administration after fasting, Cmax and tmax for ibuprofen lysinate administered postprandially were markedly different, while with FDC, these parameters were less sensitive to food intake. Taken after a meal, ibuprofen in the FDC reached tmax earlier than ibuprofen lysinate (median 1.25 vs 1.63 hours), and Cmax was approximately 13% higher, with comparable AUC, suggesting that the profile of ibuprofen was in favor of the FDC compared with ibuprofen lysinate. Thus, under real‐life conditions, ibuprofen lysinate had no PK advantage over the FDC. All preparations were well tolerated.