Table 1.
Summary of drug delivery mechanisms
| Formulations | Generic name | Proprietary names | Mode of delivery | Site of drug release |
| Azo-bonded prodrugs | Sulfasalazine | Azulfidine®; Salazopyrin®; Pyralin® | Mesalazine bound to sulfapyridine | Colon |
| Olsalazine | Dipentum® | Two mesalazine molecules bound together | Colon | |
| Balsalazide | Colazide®; Colazal® | Mesalazine bound to 4-aminobenzoyl-β-alanine | Colon | |
| pH dependent | Mesalazine | Asacol®; Mesren® | Eudragit-S coating (dissolves at pH ≥ 7) | Terminal ileum, colon |
| Salofalk®; Mesasal®; Claversal® | Eudragit-L coating (dissolves at pH ≥ 6) | Mid ileum to colon | ||
| Salofalk Granules® | Eudragit-L coating and matrix core | Mid ileum to colon | ||
| Time dependent | Mesalazine | Pentasa®, Pentasa® granules | Microspheres encapsulated within an ethycellulose semi-permeable membrane | Duodenum to colon |
| MMX | MMX mesalazine | Lialda®; Mezavant XL®; Mezavant® | Enteric coating (dissolves at pH ≥ 7). MMX of lipophilic and hydrophilic excipients | Terminal ileum and entire colon |
MMX: Multi-matrix system.