Product Information

Registration Status: Active

PENTASA PROLONGED RELEASE GRANULES 4G/SACHET is approved to be sold in Singapore with effective from 2019-01-18. It is marketed by FERRING PHARMACEUTICALS PTE LTD, with the registration number of SIN15614P.

This product contains Mesalazine 4000 mg in the form of GRANULE, DELAYED RELEASE. It is approved for ORAL use.

This product is manufactured by Ferring International Center SA in SWITZERLAND.

It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.



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)


For the treatment of active ulcerative proctitis.

Mechanism of Action

Although the mechanism of action of mesalazine is not fully understood, it appears to be topical rather than systemic. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase pathways, i.e., prostanoids, and through the lipoxygenase pathways, i.e., leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic inflammatory bowel disease, and it is possible that mesalazine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon.


20 to 30% absorbed following oral administration. 10 to 35% absorbed from the colon (rectal suppository) - extent of absorption is determined by the length of time the drug is retained in the colon.
Rapidly and extensively metabolized, mainly to N-acetyl-5-ASA (Ac-5-ASA) in the intestinal mucosal wall and the liver. Ac-5-ASA is further acetylated (deactivated) in at least 2 sites, the colonic epithelium and the liver.


Oral, mouse: LD50 = 3370 mg/kg; Oral, rat: LD50 = 2800 mg/kg; Skin, rabbit: LD50 = >5 gm/kg. There have been no documented reports of serious toxicity in man resulting from massive overdosing with mesalamine. Under ordinary circumstances, mesalazine absorption from the colon is limited.

Active Ingredient/Synonyms

3-carboxy-4-hydroxyaniline | 5-aminosalicylic acid | 5-ASA | m-Aminosalicylic acid | Mesalamine | Mesalazina | Mésalazine | Mesalazinum | p-Aminosalicylsaeure | Mesalazine |

Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.


  1. Health Science Authority of Singapore - Reclassified POM
  2. Drugbank