Abstract
The viability of the compression coating technique for colon specific delivery of two model drugs: the low water soluble indomethacin and the highly water soluble insulin, using calcium pectinate as a drug carrier was examined in vitro and in vivo. The release of indomethacin from plain matrix and compression coated calcium pectinate tablets was measured in simulated gastric and intestinal fluids, followed by a buffer solution containing a mixture of pectinolytic enzymes. It was found that highly compressed matrices, either in the form of plain tablets or in the form of compression coated tablets were able to retain their indomethacin load in simulated gastric and intestinal fluids prior to their degradation by a mixture of pectinolytic enzymes. Therefore these formulations could be used for colonspecific delivery of low water soluble drug molecules. Calcium pectinate compression coated tablets containing insulin as a drug marker were administered orally to dogs. The delayed insulin absorption was related to a break down of the drug carrier in the dogs' large intestine. Non-coated calcium pectinate tablets were not able to prevent insulin diffusion and started to release their drug content right after the administration. It is concluded that the use of calcium pectinate matrices for colon specific drug delivery may be restricted to low water soluble drugs. In the case of water soluble drugs such as insulin, an additional protective coat may be required.
Original language | English |
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Pages (from-to) | 291-295 |
Number of pages | 5 |
Journal | European Journal of Pharmaceutics and Biopharmaceutics |
Volume | 41 |
Issue number | 5 |
State | Published - 1995 |
Keywords
- calcium pectinate
- colonic delivery
- compression coat
- dog
- indomethacin
- insulin