Kumar S, Singh T, Khar R K, Sharma S N, Chauhan U P
Department of Pharmaceutics, Faculty of Pharmacy, Hamdard University, New Delhi, India.
Pharmazie. 1993 Aug;48(8):613-6.
Sterically stabilized neutral liposomes (multilamellar vesicles) were prepared by sonicating phosphatidylcholine and cholesterol (molar ratio 4:1) film in phosphate buffered saline (50 mM, pH 7.4) containing 4% Tween 20. Tc-99m-GHA was incorporated in these liposomes by treating 0.5 ml of the suspension with lyophilized GHA kit (5 mg GHA and 250 micrograms SnCl2 x 2 H2O) followed by addition of 1 ml 99mTcO4- (1-3 mCi). The labelling yield was 60-70%. Tween 20 has provided significant stability of the radiolabel as compared to that without its addition, when radiolabelled liposomes were incubated in serum up to 24 h. With respect to Tc-99m-GHA alone, radiolabelled liposomes exhibited 4- to 6-fold greater radioactivity in the blood of rabbits (15 min-24 h). Comparison of biodistribution data of radiolabelled liposomes and Tc-99m-GHA in mice demonstrated a 10- to 12-fold greater hepatic accumulation of radiolabelled liposomes with respect to that of Tc-99m-GHA throughout the period of study (15 min-24 h), though their concentration in the kidneys was comparable.
通过在含有4%吐温20的磷酸盐缓冲盐水（50 mM，pH 7.4）中超声处理磷脂酰胆碱和胆固醇（摩尔比4:1）薄膜，制备了空间稳定的中性脂质体（多层囊泡）。通过用冻干的GHA试剂盒（5 mg GHA和250 μg SnCl₂·2H₂O）处理0.5 ml悬浮液，然后加入1 ml 99mTcO₄⁻（1 - 3 mCi），将99mTc-GHA掺入这些脂质体中。标记产率为60 - 70%。当放射性标记的脂质体在血清中孵育长达24小时时，与未添加吐温20相比，吐温20显著提高了放射性标记的稳定性。就单独的99mTc-GHA而言，放射性标记的脂质体在兔血液中（15分钟至24小时）的放射性高出4至6倍。放射性标记的脂质体和99mTc-GHA在小鼠体内的生物分布数据比较表明，在整个研究期间（15分钟至24小时），放射性标记的脂质体在肝脏中的积累比99mTc-GHA高10至12倍，尽管它们在肾脏中的浓度相当。
