Abstract: Aim The aim of the present study was to prepare tablets which can rapidly disintegrate in saliva, containing active ingredient in high dose (37.5 % W/W). Methods Rapidly disintegrating tablets containing rotundine were prepared by direct compression, wet granulation and moulding, respectively. Different disintegrants and excipients were decided by single factor test. The typical disintegration time measurement and a new method of wetting time measuring were introduced for assessing rapidly disintegrating tablets. Results The tablets (80 mg) prepared by direct compression have the crushing strength of 4.0 kg·mm^-2 and rapidly disintegrate within 15 s in the saliva of healthy volunteers ; the tablets prepared by wet granulation also have sufficient strength, a little longer but acceptable disintegration time (within 25 s in saliva) ; and the tablets obtained by moulding show disintegration within 40 s in saliva but low strength (2 kg·mm^-2). Disintegration time profiles of tablets are similar to those of wetting time, and the disintegration and wetting times in vitro are similar to the disintegration time in vivo, the latter having higher correlation with that in oral cavity. Conclusion The rapidly disintegrating tablets can be prepared by using these three techniques and excipients. Both in vitro disintegration time and wetting time are necessary indexes for judgment of in vitro disintegration profile.

Key words: rotundine, rotundine, rapidly disintegrating tablets, rapidly disintegrating tablets, disintegration time, disintegration time, wetting time, wetting time