Peppermint oil caraway oil fixed combination in non-ulcer dyspepsia - Equivalent efficacy of the drug combination in an enteric coated or enteric soluble formulation

223 patients with non-ulcer dyspepsia (dysmotility type dyspepsia or essent ial/idiopathic dyspepsia, also in combination with irritable bowel syndrome ) were included in a prospective, randomised, reference- and double-blind c ontrolled multicentre trial to compare two different preparations of a fixe d combination of peppermint oil and caraway oil. The aim of the trial was t o evaluate the equivalence of the efficacy and tolerability of these two pr eparations. The test formulation consisted of the drug combination in an en teric coated capsule containing 90 mg peppermint oil and 50 mg caraway oil( 3), while an enteric soluble formulation containing 36 mg peppermint oil an d 20 mg caraway oil(4) was used as the reference. The main target item defi ned was the "difference in pain intensity between the beginning and the end of therapy", measured by the patient on a visual analogue scale (0 = no pa in, 10 = extremely strong pain). In 213 patients (n = 108 on the test prepa ration, n = 105 on the reference preparation) with mean pain intensity base line measurements of 6.1 points in the test preparation group and 5.9 point s in the reference group a statistically significant decline in pain intens ity was observed in the two groups (-3.6 resp. -3.3 points; p < 0.001; two- sided one-sample t-test), Equivalent efficacy of both preparations was demo nstrated (p < 0.001; one-sided t-test for equivalence). With respect to con comitant variables, the results in both groups were also similar. Regarding "pain frequency", the efficacy of the test preparation was significantly b etter (p = 0.04; two-sided t-test for difference). Both preparations were w ell tolerated. Despite the higher dose, the adverse event "eructation with peppermint taste" was less frequent in the group treated with the test form ulation, due to the enteric coated capsule preparation.