Balsalazide

Balsalazide is an anti-inflammatory drug used in the treatment of inflammatory bowel disease. It is sold under the brand names Giazo, Colazal in the US and Colazide in the UK. It is also sold in generic form in the US by several generic manufacturers.

Balsalazide

Clinical data
Trade names	Colazal, Giazo
AHFS/Drugs.com	Monograph
MedlinePlus	a699052
License data	US DailyMed: by mouth
Pregnancy category	AU: C
Routes of administration	By mouth
ATC code	A07EC04 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) UK: POM (Prescription only)[1] US: ℞-only
Pharmacokinetic data
Bioavailability	<1%
Protein binding	≥99%
Elimination half-life	12hr
Identifiers
IUPAC name (E)-5-([4-(2-carboxyethylcarbamoyl)phenyl]diazenyl)-2-hydroxybenzoic acid
CAS Number	80573-04-2 Y
PubChem CID	5362070
DrugBank	DB01014 Y
ChemSpider	10662422 Y
UNII	P80AL8J7ZP
KEGG	D07488 as salt: D02715
ChEBI	CHEBI:267413 Y
ChEMBL	ChEMBL1201346 N
CompTox Dashboard (EPA)	DTXSID7040653
ECHA InfoCard	100.117.186
Chemical and physical data
Formula	C17H15N3O6
Molar mass	357.322 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=C(O)c1cc(ccc1O)/N=N/c2ccc(cc2)C(=O)NCCC(O)=O
InChI InChI=1S/C17H15N3O6/c21-14-6-5-12(9-13(14)17(25)26)20-19-11-3-1-10(2-4-11)16(24)18-8-7-15(22)23/h1-6,9,21H,7-8H2,(H,18,24)(H,22,23)(H,25,26)/b20-19+ Y Key:IPOKCKJONYRRHP-FMQUCBEESA-N Y
NY (what is this?)  (verify)

It is usually administered as the disodium salt. Balsalazide releases mesalazine, also known as 5-aminosalicylic acid, or 5-ASA,^[2] in the large intestine. Its advantage over that drug in the treatment of ulcerative colitis is believed to be the delivery of the active agent past the small intestine to the large intestine, the active site of ulcerative colitis. It is in the category of disease-modifying antirheumatic drugs (DMARDs) family of medications.^[3] It is unclear exactly how it works.^[3]

Synthesis

Ex 3 is actually for Ipsalazide. See Ex 4 for Balsalazide proper. Same protocol but uses β-Alanine.

Balsalazide synthesis: Biorex Laboratories, GB 2080796 (1986).

1. Starting material is 4-aminohippuric acid, obtained by coupling para-aminobenzoic acid and glycine.
2. That product is then treated with nitrous acid to give the diazonium salt.
3. Reaction of this species with salicylic acid proceeds at the position para to the phenol to give balsalazide.