The Effect of Food on Tramadol and Celecoxib Bioavailability Following Oral Administration of Co-Crystal of Tramadol-Celecoxib (CTC): A Randomised, Open-Label, Single-Dose, Crossover Study in Healthy Volunteers.

Background And Objective: Co-Crystal of Tramadol-Celecoxib (CTC), in development for the treatment of moderate to severe acute pain, is a first-in-class co-crystal containing a 1:1 molecular ratio of two active pharmaceutical ingredients; rac-tramadol·HCl and celecoxib. This randomised, open-label, crossover study compared the bioavailability of both components after CTC administration under fed and fasting conditions.

Methods: Healthy adults received single doses of 200 mg CTC under both fed and fasting conditions (separated by a 7-day washout).

Pharmacokinetics of Tramadol and Celecoxib in Japanese and Caucasian Subjects Following Administration of Co-Crystal of Tramadol-Celecoxib (CTC): A Randomised, Open-Label Study.

Background And Objectives: Co-Crystal of Tramadol-Celecoxib (CTC) is a first-in-class active pharmaceutical ingredient (API-API) co-crystal of rac-tramadol.HCl and celecoxib in a 1:1 molecular ratio (100 mg CTC: 44 mg rac-tramadol.HCl and 56 mg celecoxib).

Pharmacokinetics of multiple doses of co-crystal of tramadol-celecoxib: findings from a four-way randomized open-label phase I clinical trial.

Aim: We compared the pharmacokinetic (PK) profiles of co-crystal of tramadol-celecoxib (CTC) vs. each reference product (alone and in open combination) after single (first dose) and multiple dosing.

Methods: Healthy adults aged 18-50 years received, under fasted conditions, 15 twice-daily doses of the following treatments (separated by ≥14-day washout): 200 mg immediate-release (IR) CTC (equivalent to 88 mg tramadol and 112 mg celecoxib; treatment 1); 100 mg IR tramadol (treatment 2), 100 mg celecoxib (treatment 3); and 100 mg IR tramadol and 100 mg celecoxib (treatment 4).

Safety, tolerability and pharmacokinetics of single and multiple doses of a novel sigma-1 receptor antagonist in three randomized phase I studies.

Aim: To assess the safety, tolerability, pharmacodynamics and pharmacokinetics in healthy subjects of a novel, highly selective, sigma-1 receptor antagonist (S1RA).

Methods: Three randomized, double-blind, placebo-controlled trials evaluated single oral doses (5-500 mg, study 101; 500-800 mg, study 106) and multiple doses (50-400 mg once daily for 8 days, study 102) of S1RA. Safety and tolerability were assessed by adverse event reporting, clinical laboratory, physical examinations, vital signs and electrocardiography, including Holter monitoring.

A medicinal-chemistry-guided approach to selective and druglike sigma 1 ligands.

Based on a medicinal-chemistry-guided approach, three novel series of druglike cycloalkyl-annelated pyrazoles were synthesized and display high affinity (pKi>8) for the sigma1 receptor. Structure-affinity relationships were established, and the different scaffolds were optimized with respect to sigma1 binding and selectivity versus the sigma2 receptor and the hERG channel, resulting in selective compounds that have Ki values (for sigma1) in the subnanomolar range. Selected compounds were screened for cytochrome P450 inhibition (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4), metabolic stability (rat and human liver microsomes), and cell-membrane permeability (Caco-2).

Ligand-induced caveolae-mediated internalization of A1 adenosine receptors: morphological evidence of endosomal sorting and receptor recycling.

The involvement of caveolae in the internalization of A(1) adenosine receptors (A(1)R) and the receptor sorting and recycling was studied in the smooth muscle cell line DDT(1)MF-2, by binding assays, by confocal microscopy, and at the structural level. The use of cholera toxin-binding subunit adsorbed to gold as a specific probe for labeling the ganglioside GM(1) and immunoelectron microscopy techniques showed that agonist stimulation produced a clustering and sequestration of adenosine receptors in caveolae. Furthermore, pull-down experiments showed there to be a direct interaction between the C-terminal domain of A(1)R and caveolin-1.