Two-layered dissolving microneedles formulated with intermediate-acting insulin
2012
Itō, Yukako | Hirono, Muneyuki | Fukushima, Keizo | Sugioka, Nobuyuki | Takada, Kanji
Two-layered dissolving microneedles (DMs) containing intermediate-acting insulin, protamine sulfate insulin (PSI), were prepared. Then a pharmacodynamic study was performed to evaluate the prolonged hypoglycemic effects in rats. The DMs were approximately 497±5μm long, with 303±3μm diameter at their base. The length of the insulin loaded space was 182±4μm. PSI contents in DMs were 0.51±0.02IU. A three-month stability study showed that 99.9±1.4% of PSI was recovered at 4°C. As the temperature increased to 40°C, recovery decreased to 97.5±2.0%. PSI was released within 5min from DMs. Hypoglycemic effects of PSI DMs were evaluated in rats where subcutaneous injection preparations were used as references. Total area above the plasma glucose level (% of the pre-dose level) vs. time curve as an index of hypoglycemic effect was 144.0±16.0%h and 243.3±8.5%h for PSI DMs at 1.46 and 3.28IU/kg. The relative pharmacologic availability of PSI from DMs were 100.2±9.8% and 91.4±4.1%. No significant difference of hypoglycemic curves was found between DMs and injection solutions, which suggests the usefulness of two-layered DMs of PSI for the displacement therapy of sc injection preparation.
显示更多 [+] 显示较少 [-]