著者

村田 晃 平田 祥子 松岡 昌義 日比 善朗 柏原 俊夫 北森 信之 玉井 浩 美濃 真

出版者

公益社団法人 日本ビタミン学会

雑誌

ビタミン (ISSN:0006386X)

巻号頁・発行日

vol.64, no.5-6, pp.285-294, 1990-06-25 (Released:2018-03-17)

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Two multipore-type sustained-release preparations (VC-SR-A and VC-SR-B) containing 500 mg of vitamin C were prepared, which were coated with mixtures of water-soluble polyethylene glycol and insoluble ethylcellulose. The preparations differed in the dissolution profile of vitamin C; the in vitro release rates being 7.3 %/h for VC-SR-A and 14.2 %/h for VC-SR-B. The bioavailability of vitamin C after the administration of a single dose was examined in six subjests (25-32 years) who had been saturated with vitamin C, and compared with an osmorelease-type sustained-release preparation (AcuSystem C) and a conventional immediate-release preparation (VC-IR) in a crossover trial. The mean T_<max> was 3 h for VC-IR, 6 h for VC-SR-B, 7 h for VC-SR-A and 8.5 h for AcuSystem C. Mean C_<max> (mg/100ml) were 0.28 for VC-SR-A, 0.40 for AcuSystem C, 0.48 for VC-SR-B and 0.74 for VC-IR. The mean AUC (mg.h/100 ml, 0-24 h) was 3.43 for VC-SR-A, 5.73 for AcuSystem C, 6.68 for VC-SR-B and 6.80 for VC-IR. The mean percentages of the dose excreted in the 24-h urine were 7.7 for VC-SR-A, 17.6 for AcuSystem, 23.4 for VC-SR-B and 39.1 for VC-IR. The results indicate that for VC-SR-B the rate of bioavailability is slower but prolonged and thus the extent of bioavailability is almost equal to that of VC-IR. Also, concerning retention of vitamin C in the body, VC-SR-B seems to be preferable to VC-IR.