The (alfaS, 4S)-isomer of Brivaracetam is one of the two mirror-image forms (enantiomers) of the drug Brivaracetam. Enantiomers are molecules that have the same chemical formula and structure but are mirror images of each other and can have different pharmacological properties. In the case of Brivaracetam, the (alfaS, 4S)-isomer is considered the inactive form, meaning it does not contribute significantly to the therapeutic effects of the drug. The (alfaR, 4R)-isomer is the pharmacologically active form responsible for Brivaracetam's antiepileptic effects. This active isomer has a higher affinity for the synaptic vesicle glycoprotein 2A (SV2A) receptor, which is believed to be involved in the regulation of neurotransmitter release. Chemicea Pharma is one of the leading manufacturer and exporter of Brivaracetam (alfaS, 4S)-Isomer, CAS No 357336-19-7