Fast-disintegrating sublingual epinephrine tablets: Effect of tablet dimensions on tablet characteristics

The purpose of this study was to evaluate the effect of changing dimensions on the hardness ( H), disintegration time ( DT), and wetting time (WT) of fast-disintegrating epinephrine tablets for sublingual administration as potential first aid treatment for anaphylaxis. Tablet formulations I and II, containing 0% and 10% epinephrine bitartrate, respectively, and weighing 150 mg were prepared by direct compression. Formulations were compressed at a range of forces using an 8/32 '' die with concave punches (CP); a 10/32 '' and an 11/32 '' die with CP and flat punches ( FP). Tablet weight variation, content uniformity, thickness, H, DT, and WT were measured. The 8/32 '', 10/32 '', and 11/32 '' dies resulted in tablet thickness of ranges 0.25 - 0.19 '', 0.17 - 0.1 '', and 0.16 - 0.08 '', respectively. The DT and WT using the 8/32 '' die were <= 10 and <= 30 sec, respectively, at H <= 5.4 +/- 0.2 kg for formulation I, and H <= 5.4 +/- 0.3 kg for formulation II. The DT and WT were = 10 and = 30 sec, respectively, using 10/32 '' die/CP, 10/32 '' die/FP, 11/32 '' die/CP, and 11/32 '' die/FP at H <= 6.2 +/- 0.6 kg, <= 6.8 +/- 0.4 kg, <= 4.9 +/- 0.1 kg, and <= 7.2 +/- 0.3 kg, respectively, for formulation I. For formulation II, the DT and WT were = 10 sec and = 30 sec, respectively, when H < 4 kg. No difference in DT and WT was observed between concave and flat tablets. The 11/32 '' and 10/32 '' dies resulted in more ideal tablet dimensions for sublingual administration, but H must be maintained < 4 kg to ensure rapid DT and WT.