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PK Properties (pk + property)

Distribution by Scientific Domains

Medical Sciences	60%
Chemistry	40%

Selected Abstracts

Pharmacokinetics of dipeptidylpeptidase-4 inhibitors

DIABETES OBESITY & METABOLISM, Issue 8 2010
A. J. Scheen
Type 2 diabetes (T2DM) is a complex disease combining defects in insulin secretion and insulin action. New compounds have been developed for improving glucose-induced insulin secretion and glucose control, without inducing hypoglycaemia or weight gain. Dipeptidylpeptidase-4 (DPP-4) inhibitors are new oral glucose-lowering agents, so-called incretin enhancers, which may be used as monotherapy or in combination with other antidiabetic compounds. Sitagliptin, vildaglipin and saxagliptin are already on the market in many countries, either as single agents or in fixed-dose combined formulations with metformin. Other DPP-4 inhibitors, such as alogliptin and linagliptin, are currently in late phase of development. The present paper summarizes and compares the main pharmacokinetics (PK) properties, that is, absorption, distribution, metabolism and elimination, of these five DPP-4 inhibitors. Available data were obtained in clinical trials performed in healthy young male subjects, patients with T2DM, and patients with either renal insufficiency or hepatic impairment. PK characteristics were generally similar in young healthy subjects and in middle-aged overweight patients with diabetes. All together gliptins have a good oral bioavailability which is not significantly influenced by food intake. PK/pharmacodynamics characteristics, that is, sufficiently prolonged half-life and sustained DPP-4 enzyme inactivation, generally allow one single oral administration per day for the management of T2DM; the only exception is vildagliptin for which a twice-daily administration is recommended because of a shorter half-life. DPP-4 inhibitors are in general not substrates for cytochrome P450 (except saxagliptin that is metabolized via CYP 3A4/A5) and do not act as inducers or inhibitors of this system. Several metabolites have been documented but most of them are inactive; however, the main metabolite of saxagliptin also exerts a significant DPP-4 inhibition and is half as potent as the parent compound. Renal excretion is the most important elimination pathway, except for linagliptin whose metabolism in the liver appears to be predominant. PK properties of gliptins, combined with their good safety profile, explain why no dose adjustment is necessary in elderly patients or in patients with mild to moderate hepatic impairment. As far as patients with renal impairment are concerned, significant increases in drug exposure for sitagliptin and saxagliptin have been reported so that appropriate reductions in daily dosages are recommended according to estimated glomerular filtration rate. The PK characteristics of DPP-4 inhibitors suggest that these compounds are not exposed to a high risk of drug,drug interactions. However, the daily dose of saxagliptin should be reduced when coadministered with potent CYP 3A4 inhibitors. In conclusion, besides their pharmacodynamic properties leading to effective glucose-lowering effect without inducing hypoglycaemia or weight gain, DPP-4 inhibitors show favourable PK properties, which contribute to a good efficacy/safety ratio for the management of T2DM in clinical practice. [source]

Reformulated BeneFix®: efficacy and safety in previously treated patients with moderately severe to severe haemophilia B

HAEMOPHILIA, Issue 3 2007
T. LAMBERT
Summary. BeneFix®, the only recombinant factor IX (FIX), has been reformulated. The reformulation involves a change in diluent and allows for more concentrated infusions of recombinant FIX. A double-blind, randomized, pharmacokinetic (PK) crossover study demonstrated that reformulated BeneFix was bioequivalent to original BeneFix and follow-up PK evaluation after 6 months of treatment demonstrated the PK stability of reformulated BeneFix after multiple exposures. Favourable efficacy and safety profiles, consistent with those already well-established for original BeneFix, were observed: 81.1% of haemorrhages resolved with only a single infusion; 85.3% of initial treatment response ratings were Excellent or Good; more than half of the subjects using reformulated BeneFix for routine prophylaxis (11 of 17, 64.7%) had no spontaneous haemorrhages during their 6,12 month course of prophylactic treatment, with an overall spontaneous bleeding rate of 0.72 year,1; and for the single surgical procedure (knee washing), treatment was rated Useful. In addition, there was no FIX inhibitor development, allergic-type manifestations, or thrombogenic complications with more than 1100 infusions (nearly 5.2 million IUs) administered in this trial. All efficacy and safety outcomes from this study were achieved with more concentrated recombinant protein infusions than that possible with original BeneFix, and utilization of the 2000 IU per vial dosage strength, newly introduced with the reformulated product, was high (>62%). The reformulation of BeneFix allows smaller delivery volumes and an increased choice of dosage strengths without altering the PK properties (including incremental recovery and half-life) or the established efficacy and safety profile of recombinant FIX. [source]

N-in-1 dosing pharmacokinetics in drug discovery: Experience, theoretical and practical considerations

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2008
Kan He
Abstract N-in-1 (or cassette) dosing pharmacokinetics (PK) has been used in drug discovery for rapid assessment of PK properties of new chemical entities. However, because of potential for drug,drug interactions this procedure is still controversial. This study was to retrospectively evaluate the N-in-1 dosing approach in drug discovery with an emphasis on the potential for drug,drug interactions. The systemic clearance, volume of distribution, oral bioavailability, and renal excretion of the 31 lead compounds in rats, dogs or chimpanzees were significantly correlated between the N-in-1 dosing and discrete studies with r values of 0.69, 0.91, 0.53, and 0.83 (p,<,0.005 for all), respectively. PK parameters for 11 quality control compounds which were involved in 194 N-in-1 studies for screening approximately 1000 compounds had coefficient of variations of less than 70%. The intrinsic microsomal clearances generated from the N-in-1 and discrete incubations were nearly identical (r,=,0.97, p,<,0.0001). The intrinsic clearances of quality control compound from the N-in-1 incubations were consistent with its discrete CLint estimate (cv: 5.4%). Therefore, N-in-1 dosing is a useful approach in drug discovery to quickly obtain initial PK estimates. Potential drug,drug interactions that result in confounding PK estimates do not occur as frequently as expected. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:2568,2580, 2008 [source]

Design and Synthesis of Selective and Potent Orally Active S1P5 Agonists

CHEMMEDCHEM, Issue 10 2010
Dr. Henri Mattes
Putting the brakes on demyelination: Fingolimod (FTY720) was recently shown to significantly decrease relapse rates in patients with multiple sclerosis. This drug attenuates the trafficking of harmful T-cells entering the brain by regulating sphingosine-1-phosphate (S1P) receptors. We designed, synthesized, evaluated 2H -phthalazin-1-one derivatives (e.g., 1,L) as selective S1P5 receptor agonists; these compounds are highly potent and selective, with good PK properties, and significant activity in oligodendrocytes. [source]