arbaclofen placarbil MR prototype A

**Arbaclofen placarbil MR prototype A** is a *modified-release formulation* of arbaclofen placarbil, a prodrug of R-baclofen (the pharmacologically active R-enantiomer of baclofen). Arbaclofen placarbil is designed for enhanced absorption throughout the gastrointestinal tract—including the colon—via active and passive mechanisms (monocarboxylate transporter type 1), overcoming the limited absorption window of baclofen[3][9]. After oral administration, arbaclofen placarbil is rapidly converted to R-baclofen, which is a selective agonist at the gamma-aminobutyric acid type B receptor (GABA-B), producing inhibitory effects in the central nervous system[5][3][7]. Sustained- or modified-release (MR) versions aim to provide more continuous exposure to R-baclofen, lower plasma fluctuations, and permit less frequent dosing[9][3]. Development of MR formulations was intended for indications including spasticity (notably in multiple sclerosis and spinal cord injury), gastroesophageal reflux disease (GERD), and, investigationally, alcohol use disorder and autism spectrum disorder[1][2][5][7][9]. Clinical trial data showed modest or no significant efficacy over placebo for GERD, but benefit was observed for certain spasticity indications; adverse events were generally dose-related and mild to moderate[1][4][9].

Other names

arbaclofen placarbil extended-releasearbaclofen placarbil sustained-releasearbaclofen placarbil modified-releasearbaclofen placarbil MRarbaclofen placarbil SRXP19986 SR1XP-19986 SR1XP 19986 SR1