Most regulatory guidelines including those from the FDA, recommend that the whole tablets, not the crushed tablets - should be tested for dissolution.
Why not crush the tablets?
You might think that since chewable tablets are designed to be chewed, crushing them for dissolution testing could work. However, that’s not recommended. Why? Currently there is no validated method for crushing chewable tablets before dissolution testing, so regulatory bodies require testing the whole intact tablet.
Same dissolution method as conventional tablets?
Essentially, the basic dissolution testing procedure for chewable tablets should follow the same procedure as conventional tablets. The logic here is that some patients might swallow the tablet without proper chewing, in which case the drug will still need to be released in the body to deliver the intended effect.
Adjustments for chewable tablets
Since chewable tablets don’t disintegrate in the same way as conventional tablets, certain adjustments to the dissolution conditions might be necessary. For example:
- Agitation rate: You might need to increase the agitation to help disintegrate the tablet
- Specifications: Increase in the test duration may be required considering the slower disintegration rate of the chewable tablet
- Apparatus 3: The reciprocating cylinder (USP Apparatus 3) with added glass beads may be used to create a more ‘intense’ agitation during dissolution testing.
Dissolution testing for product characterization
According to the FDA guidelines , when developing a chewable tablet you should conduct dissolution testing on intact tablets in at least four different media:
- Water
- Aqueous media at pH 1.2
- Buffered aqueous media at pH 4.5
- Buffered aqueous media at pH 6.8
These tests are typically done using standard dissolution testing equipment like USP Apparatus 1 (basket), USP Apparatus 2 (Paddle) or USP Apparatus 3 (reprobating cylinder).
Read also:
- Dissolution Testing for Gelatin Capsules
- Dissolution Specification Setting Procedure as per FDA Guidance
Resource Person: Pearl Pereira Nambiar
