Available Mesalamine Formulations in Canada
Several mesalamine (5-aminosalicylic acid or 5-ASA) formulations are available in Canada, each with different delivery mechanisms designed to target specific areas of the gastrointestinal tract. 1
Oral Formulations
pH-dependent Release/Resin Coated
- Asacol/Mesren (400mg tablets)
- Asacol-HD (800mg tablets)
- Salofalk (tablets)
- Delzicol (400mg tablets)
- These formulations use Eudragit-S coating that dissolves at pH ≥7.0, releasing medication in the terminal ileum and colon
Time-Controlled Release
- Pentasa (250mg, 500mg tablets/capsules)
- Contains ethylcellulose-coated microgranules that release medication throughout the small intestine and colon
Multi-Matrix System (MMX)
- Lialda/Mezavant (1200mg tablets)
- Uses enteric coating that dissolves at pH ≥7.0 with a matrix of lipophilic and hydrophilic excipients for extended release throughout the colon
Delayed and Extended Release
- Apriso (375mg capsules)
- Contains mesalamine granules in a polymer matrix with enteric coating that dissolves at pH ≥6.0
- Primarily approved for maintenance therapy
Carrier Molecule Formulations (Diazo-bonded)
These prodrugs are converted to 5-ASA in the colon by bacterial enzymes:
Salazopyrin/Azulfidine (500mg tablets)
- 5-ASA linked to sulfapyridine
- 4g provides approximately 1.6g of 5-ASA
Dipentum/Olsalazine (250mg tablets)
- Two 5-ASA molecules linked by an azo bond
- 2-3g daily provides 1.6-2.4g of 5-ASA
Colazide/Balsalazide (750mg tablets)
- 5-ASA linked to 4-aminobenzoyl-β-alanine
- 2-6.75g daily provides 0.7-2.4g of 5-ASA
Rectal Formulations
Mesalamine suppositories
- For ulcerative proctitis
- Strongly recommended by the AGA for distal disease 1
Mesalamine enemas, foam or gel
- For left-sided colitis
- More effective than rectal corticosteroids 1
Important Considerations
Phthalate Content
Some mesalamine formulations in Canada (such as older versions of Asacol and Mesasal) contain dibutyl phthalate (DBP), which has potential teratogenic effects. For women contemplating pregnancy, switching to a non-DBP containing formulation is recommended 1.
Dosing Strategy
- Low dose: <2g/day
- Standard dose: 2-3g/day
- High dose: >3g/day (up to 4.8g/day maximum)
Once-daily dosing is as effective as multiple daily doses and improves adherence 1.
Formulation Selection
The choice of formulation should be based on the location of disease:
- Proctitis: Suppositories or distal-acting oral formulations
- Left-sided colitis: Enemas and oral formulations
- Extensive colitis: Oral formulations with combined rectal therapy
Efficacy Considerations
Mesalamine granules have shown superior efficacy compared to tablets for distal ulcerative colitis, particularly for proctosigmoiditis 2.
The availability of specific brands and formulations may vary across different regions of Canada, and some formulations may have been updated since their initial release to remove potentially harmful excipients like DBP.