Biomaterial Database

Determination of the pK values of 5-aminosalicylic acid and N-acetylaminosalicylic acid and comparison of the pH dependent lipid-water partition coefficients of sulphasalazine and its metabolites. 1985

H Allgayer, and J Sonnenbichler, and W Kruis, and G Paumgartner

Sulphasalazine (SASP), used in the treatment of inflammatory bowel disease, is split into sulphapyridine (SP) and 5-aminosalicylic acid (5-ASA) in the colon. Lower plasma levels of SASP and 5-ASA as compared to those of SP may be due to different absorption rates from the colon because of different pK values and pH dependent lipid-water partition coefficients. In this study we determined the pK values of 5-ASA and its major metabolite, N-acetyl amino-salicylic acid (AcASA), by 13C-NMR spectroscopy and compared the pH dependent apparent benzene-water partition coefficients (Papp) of SASP, SP and 5-ASA with respect to their different plasma levels. The COOH group of 5-ASA had a pK value of 3.0, the -NH3+ group had 6.0, the -OH group 13.9; the -COOH group of AcASA had 2.7 and the -OH group 12.9; The Papp of SASP (0.042 +/- 0.004) and 5-ASA (0.059 +/- 0.01) were significantly lower than that of SP (0.092 +/- 0.03) (at pH 5.5).

UI	MeSH Term	Description	Entries
D002627	Chemistry, Physical	The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.	Physical Chemistry,Chemistries, Physical,Physical Chemistries
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000636	Aminosalicylic Acids	A group of 2-hydroxybenzoic acids that can be substituted by amino groups at any of the 3-, 4-, 5-, or 6-positions.	Acids, Aminosalicylic
D012460	Sulfasalazine	A drug that is used in the management of inflammatory bowel diseases. Its activity is generally considered to lie in its metabolic breakdown product, 5-aminosalicylic acid (see MESALAMINE) released in the colon. (From Martindale, The Extra Pharmacopoeia, 30th ed, p907)	Salicylazosulfapyridine,Asulfidine,Azulfadine,Azulfidine,Azulfidine EN,Colo-Pleon,Pleon,Pyralin EN,Salazopyrin,Salazosulfapyridine,Sulfasalazin medac,Sulfasalazin-Heyl,Sulfasalazine FNA,Sulphasalazine,Ucine,Ulcol,ratio-Sulfasalazine,Colo Pleon,Sulfasalazin Heyl,ratio Sulfasalazine
D055598	Chemical Phenomena	The composition, structure, conformation, and properties of atoms and molecules, and their reaction and interaction processes.	Chemical Concepts,Chemical Processes,Physical Chemistry Concepts,Physical Chemistry Processes,Physicochemical Concepts,Physicochemical Phenomena,Physicochemical Processes,Chemical Phenomenon,Chemical Process,Physical Chemistry Phenomena,Physical Chemistry Process,Physicochemical Phenomenon,Physicochemical Process,Chemical Concept,Chemistry Process, Physical,Chemistry Processes, Physical,Concept, Chemical,Concept, Physical Chemistry,Concept, Physicochemical,Concepts, Chemical,Concepts, Physical Chemistry,Concepts, Physicochemical,Phenomena, Chemical,Phenomena, Physical Chemistry,Phenomena, Physicochemical,Phenomenon, Chemical,Phenomenon, Physicochemical,Physical Chemistry Concept,Physicochemical Concept,Process, Chemical,Process, Physical Chemistry,Process, Physicochemical,Processes, Chemical,Processes, Physical Chemistry,Processes, Physicochemical
D019804	Mesalamine	An anti-inflammatory agent, structurally related to the SALICYLATES, which is active in INFLAMMATORY BOWEL DISEASE. It is considered to be the active moiety of SULPHASALAZINE. (From Martindale, The Extra Pharmacopoeia, 30th ed)	5-Aminosalicylate,Mesalazine,5-Aminosalicylic Acid,Asacol,Asacolon,Ascolitin,Canasa,Claversal,Fivasa,Lixacol,Mesalamine Hydrochloride,Mesalamine Monosodium Salt,Mesasal,Novo-5 ASA,Pentasa,Rowasa,Salofalk,m-Aminosalicylic Acid,meta-Aminosalicylic Acid,5 Aminosalicylate,5 Aminosalicylic Acid,Hydrochloride, Mesalamine,Monosodium Salt, Mesalamine,Novo 5 ASA,m Aminosalicylic Acid,meta Aminosalicylic Acid