Saburo Murata
Osaka University
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Publication
Featured researches published by Saburo Murata.
Journal of Drug Targeting | 1994
Satoshi Ueda; Rinta Ibuki; Akio Kawamura; Saburo Murata; Toshiya Takahashi; Sumihisa Kimura; Takehisa Hata
Time-Controlled Explosion System (TES) has the time-controlled drug release property with a pre-designed lag time. The drug release from the system is initiated by destruction of the membrane. In this study, metoprolol tartrate was used as a model drug. After five types of TES with different in vitro lag times were orally administrated to dogs, plasma metoprolol concentration was monitored. There existed a good correlation between in vitro and in vivo lag time, while the extent of absorbed metoprolol decreased with prolongation of lag time. Next, the in vivo drug release behavior was directly investigated using five different colored TES with a lag time of two hours. Each TES was consecutively administrated to the fasted dogs at predetermined intervals. The amount of metoprolol released was monitored by recovering the administered TES from the gastrointestinal trace. The in vivo release profile corresponded with the in vitro one. It is demonstrated that TES can release the drug in in vivo conditions similarly to in vitro. Based on these results, the decrease of the absorption is suggested to be caused by increased hepatic first-pass metabolism of the drug due to the retarded release rate with longer lag time.
International Journal of Pharmaceutics | 1998
Saburo Murata; Satoshi Ueda; Fumio Shimojo; Yuji Tokunaga; Takehisa Hata; Norio Ohnishi
Abstract In vivo oral absorption study of time-controlled explosion system (TES), using gastrointestinal (GI) physiology regulated dogs, was carried out to predict the feasibility in humans. TES is characterized by rapid drug release with a pre-programmed lag time, which can provide a programmed release system synchronized with circadian rhythm (e.g. asthma attack in the morning), a colon targeting system and a sustained release system with different lag times. In this study, TES containing diclofenac sodium with different lag times of 3 and 6 h (TES-3h and TES-6h) were prepared. TES-3h exhibited good performance in all six GI physiology regulated dogs without remarkable reduction of AUC. In the case of TES-6h, drug absorption was observed ∼6 h after administration in four of six dogs, but plasma level was low. Further, the location of the dosage forms after oral administration was estimated from the gastric emptying time (GET) and the small intestinal transit time (SITT) using a double marker method. As a result, in vivo performance of TES correlated with the intestinal location. It was concluded that TES-3h would perform well in humans and that the environmental water content in the GI tract affected the in vivo dissolution profile of TES when the drug release was initiated after entering the colon.
Journal of Pharmacy and Pharmacology | 1996
Jiro Fujisaki; Yuji Tokunaga; Toshiya Takahashi; Saburo Murata; Fumio Shimojo; Takehisa Hata
Disodium (fluorescein‐6−carbonyloxy)acetoaminomethylene bisphosphonate (CF‐BP), a prodrug of 6−carboxy‐fluorescein, is efficiently absorbed by the skeleton where it hydrolyses to carboxyfluorescein. An osteotropic drug‐delivery system based on this bisphosphonic prodrug has been developed as a novel method for site‐specific and controlled delivery of drugs to the bone. In this study the physicochemical properties of the prodrug have been characterized by investigating the affinity of CF‐BP for hydroxyapatite and the hydrolysis of the compound to carboxyfluorescein.
Archive | 1993
Akira Kagayama; Sumihisa Kimura; Saburo Murata; Sachiyo Tanimoto; Takehisa Hata
Chemical & Pharmaceutical Bulletin | 1994
Satoshi Ueda; Rinta Ibuki; Sumihisa Kimura; Saburo Murata; Toshiya Takahashi; Yuji Tokunaga; Takehisa Hata
Bulletin of the Chemical Society of Japan | 1987
Hideaki Fujiwara; Haruyuki Arakawa; Saburo Murata; Yoshio Sasaki
Archive | 1996
Takehisa Hata; Akira Kagayama; Sumihisa Kimura; Satoshi Ueda; Saburo Murata
Archive | 1998
Akira Kagayama; Sachiyo Tanimoto; Saburo Murata; Takehisa Hata
Archive | 1992
Takehisa Hata; Akira Kagayama; Sumihisa Kimura; Satoshi Ueda; Saburo Murata
Chemical & Pharmaceutical Bulletin | 1991
Hideaki Fujiwara; Hirofumi Yoshikawa; Saburo Murata; Yoshio Sasaki