Description_x000D_ Application_x000D_ Sulfobromophthalein disodium salt hydrate has been used as a positive control to study the interaction of 11-keto-β-boswellic acid (KBA) and 3-acetyl-11-keto-β-boswellic acid (AKBA) with organic anion transporter OATP1B3._x000D_ Packaging_x000D_ 5 g in glass bottle_x000D_ Biochem/physiol Actions_x000D_ Sulfobromophthalein (BSP) is a high affinity organic ion substrate for organic anion transporting polypeptides (OATPs) and has been used as a substrate for multidrug resistance associated protein 2 (Mrp2). BSP is transported into hepatocytes by OATPs and, after conjugation to glutathione, is excreted into bile by Mrp2. It was found to inhibit the aldo-keto reductase ARK1C20.