Classical approaches which are usually based on a pH-triggered or time-controlled polymeric coating of a drug loaded core (tablet, capsule or multiparticulate system) can be applied. pH-triggered coatings are resistant to acidic gastric pH and start to dissolve and thus release the drug substance when the intestinal pH reaches a value of 6.5 to 7.0, typically in the ileocaecal region. Although this is a well-established strategy, the drawback is that these coatings completely rely on the intestinal pH, which shows a high inter- and intra-subject variability, especially in patients with IBD conditions.
Time-controlled drug delivery systems, intended for colon targeting, release the drug over a prolonged time period and preferably exhibit a lag time before reaching the colon. However, these coatings are relying on the gastro-intestinal transit time which is again a high variable factor between subjects. Hence, these classical systems could result in a failure to deliver the drug as intended at the site of action.
To mitigate this risk and allow a more colon specific release, more advanced systems can be offered. These could be based on combining pH-triggered systems with other strategies, such as biodegradable polysaccharides. In that case, the dissolution of the coating is relying on two different mechanisms (pH and enzymatic degradation), which results in a lower failure rate, compared to the single pH-triggered systems.
In scope of colon targeting, a multiparticulate drug delivery system (such as mini-tablets and coated beads) is preferred over a monolithic system. The advantages of having a system where the dose is divided over multiple subunits are versatile: a lower risk of dose dumping, a more reproducible gastro-intestinal transit time, dose flexibility, the option to combine incompatible drugs, etc. Eurofins CDMO has the capabilities to encapsulate the minitablets or coated beads providing a convenient and patient-friendly final dosage form.
