抄録
This study was performed to make a better lipid microsphere (LM) preparation of PGE1 derivatives. At first, we measured the inhibitory effects on human platelet aggregation by PGE1 and its several esters. Subsequently, we measured their activity after incubation in human serum. The results showed that the activity of PGE1 butyl ester, methyl ester or pivaryl ester became stronger after the incubation in serum. After intravenious injection, PGE1 butyl ester, methyl ester or pivaryl ester may be changed to PGE1 by plasma esterase. When the LM prepations of PGE1 and its several esters were incubated in 1.6% bovine serum albumin solution, it was shown that PGE1 as such was released rapidly from LM, while the release of PGE1 butyl ester, PGE1 methyl ester and PGE1 pivaryl ester were slow.
Thus PGE1 butyl ester, methyl ester, pivaryl ester in LM, injected intravenously, may not be released largely in plasma before the distribution of LM to the target site. These data suggest that LM preparation of PGE1 butyl ester, methyl ester or pivaryl ester would be a better LM preparation than lipo-PGE1.
