2016 年 42 巻 5 号 p. 350-355
EBRANTIL® Capsules are a drug product of urapidil, an alpha-1 adrenergic receptor antagonist, in the form of enteric/sustained-release granule filled capsules. This product can be administered as a solution prepared by the simple suspension method (SSM) to patients with gastrostomy through tubes; however, there is no information on the elution behavior of the drug administered by SSM.
In this study, one EBRANTIL® Capsules 15 mg was put in 20 mL of purified water or Japanese Pharmacopoeia (JP) 1st fluid for the dissolution test (pH 1.2) of 55 and 37℃. The test container was left for 10 minutes, then the content was suspended. The dissolution test was carried out in JP 1st fluid.
The elution of urapidil from EBRANTIL® Capsules untreated by SSM was 30% or less in 60 minutes. Ninety percent or greater of urapidil eluted in 30 minutes treated with water of 55℃. The elution rate of urapidil treated with water of 37℃ was relatively slower than that; however, 60% or greater urapidil eluted in 60 minutes. The elution behavior of urapidil from the capsule treated with JP 1st fluid was almost the same as that of the untreated EBRANTIL® Capsules. These data suggest that the granules in the capsules were slightly dissolved in JP 1st fluid, but they dissolved immediately in water of 55 and 37℃.
In conclusion, EBRANTIL® Capsules should not be administered by SSM to avoid lowering blood pressure when treating patients.