Assessing gastrointestinal motility and disintegration profiles of magnetic tablets by a novel magnetic imaging device and gamma scintigraphy.

Purpose: To validate Magnetic Moment Imaging (MMI) for the investigation of gastrointestinal transit and disintegration of solid dosage forms and to correlate the MMI findings with the corresponding gamma scintigraphic data.

Materials And Methods: Three magnetic tablets (MTs) were investigated using in vitro and in vivo tests. The clinical study was a four-way, crossover study with the following arms: (a) immediate-release tablets administered in fasted state; (b) immediate-release tablets administered after 400mL of Clinutren ISO; (c) enteric-coated tablets administered in the fasted state; and (d) non-disintegrating tablets studied in the lightly fed state (100mL of Clinutren ISO).

Results: In both the in vitro and in vivo studies, tablets were detected successfully by MMI and scintigraphy. There was a good correlation between gastric residence times and positional data (in the x, y and y, z-axes). In addition, MMI revealed early swelling behaviour of the tablet matrix. There was excellent agreement for the disintegration times of MT(A) in the fasted arm (scintigraphy 12.0+/-4.4min, MMI 11.8+/-4.4min). In the MT(A)-fed arm, onset times determined by scintigraphy were delayed in three subjects when compared to the corresponding MMI results. Delayed disintegration was observed with MT(A) administered after food (p<0.01) in both the techniques.

Conclusion: The MMI device is a reliable imaging tool for tracking the transit and disintegration of a magnetic tablet through the gastrointestinal tract.