Pregabalin in bulk supply 148553-50-8 global trade Hot Sale 148553-50-8

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Pregabalin in bulk supply global trade Hot Sale 148553-50-8

As a follow-up to its g-aminobutyric acid (GABA) agonist gabapentin, Pfizer has developed and launched pregabalin for the treatment of epilepsy and neuropathic pain. Although pregabalin is a structural analog of GABA, it does not interact with GABA-A or GABA-B receptors or influence GABA uptake. The exact mechanism of action is unclear, but pregabalin may reduce excitatory neurotransmitter release by binding to the α2-δ protein subunit of voltage-gated calcium channels. The resulting inhibition of excess neuronal activity is believed to be the basis for pregabalin’s efficacy in epilepsy and neuropathic pain alleviation. Since the activity is attributed to the (S′)-enantiomer alone, an efficient asymmetric synthesis is employed for commercial production. The key step is the asymmetric hydrogenation of 3-cyano-5-methyl-3-hexenoic acid using a chiral rhodium catalyst to afford an intermediate that is enriched in the (S′)-enantiomer. The cyano group is ultimately reduced by routine hydrogenation with a nickel catalyst. Further enrichment of the final product is realized by selective recrystallization with (S′)-mandelic acid or simply recrystallizing from water/isopropanol. Compared to gabapentin, pregabalin is 2- to 10-fold more potent in various animal models. For example, in preventing maximal electroshock seizures (MES) in mice, pregabalin has an ED₅₀ of 20 mg/kg p.o. versus 87 mg/kg for gabapentin. A comparable increase in potency is also observed in the rat MES model (ED₅₀=1.8mg=kg p.o. for pregabalin versus 10.3 mg/kg for gabapentin). In addition, pregabalin’s linear pharmacokinetics (Cmax relates to dose) translates to better predictability of pharmacological effects. It has 90% oral bioavailability, with an elimination half-life of approximately 6 h. The primary route of excretion is via the renal system with negligible metabolism. Furthermore, its lack of activity at the cytochrome P450 enzymes was reflected in an absence of pharmacokinetic drug-drug interactions in relevant studies. In a placebocontrolled, fixed dose (up to 600mg/day) trial with pregabalin as an adjunctive therapy for epilepsy, 14 to 51% of patients showed at least a 50% decrease in seizure frequency with a clear dose-response relationship. In a flexible dosing group, (150 mg/day to 600 mg/day), the seizure reduction rate was 35.4%compared to 40.3% for a fixed dose of 600mg/day and 10.6% for placebo. The most common side effects were dizziness (29%) and somnolence (21%). In addition, weight gain (equal to or more than 7% increase from baseline) occurred in 40% of patients in the 12-week study; however, there was no affect on male fertility or efficacy of oral contraceptives in women. Regarding the use of pregabalin in treating painful diabetic peripheral neuropathy, oral administration of 300 and 600 mg/day t.i.d. was superior to placebo (39–48% compared to 15–18% with placebo) in relieving pain and improving pain-related sleep interference. While pregabalin was originally developed as an anticonvulsant for epilepsy, its success in treating neuropathic pain has led to its exploration in treating other CNS disorders, such as, anxiety, social phobia, and fibromyalgia.