目的 制備不同粒徑聚乙二醇化維生素K₁（VK₁）脂質(zhì)體，并對其進(jìn)行制劑學(xué)表征，考察體內(nèi)藥動學(xué)和促凝藥效。方法 采用薄膜分散法制備不同粒徑的VK₁脂質(zhì)體，采用馬爾文粒徑儀測定粒徑、聚合物分散性指數(shù)（PDI）、Zeta電位；透射電子顯微鏡觀察形態(tài)；以粒徑為指標(biāo)，考察脂質(zhì)體在4℃下儲存1個月、在磷酸緩沖液（PBS，pH 6.8）及pH 1.2水溶液中48 h的穩(wěn)定性；采用超濾離心法測定包封率與載藥量；采用大鼠在體腸吸收模型考察腸吸收特性；ig給藥考察脂質(zhì)體在大鼠體內(nèi)藥動學(xué)行為；以華法林鈉誘導(dǎo)大鼠低凝血酶原血癥，采用ELISA試劑盒檢測血漿中凝血因子II、V、VII和IX含量，檢測凝血酶原時間（PT），評價不同粒徑VK₁脂質(zhì)體（2 mg·kg^-1）促凝效果。結(jié)果 制備了3種VK₁脂質(zhì)體（Lip-180、Lip-120、Lip-60），粒徑分別為（182.40±2.17） nm、（114.38±0.60） nm和（68.42±0.73） nm，PDI分別為0.21±0.01、0.12±0.00和0.17±0.01 ，電位分別為（-27.67±1.58）、（-22.93±1.81）、（-26.63±1.37）mV，脂質(zhì)體均呈球形，分布均勻，包封率均>90%，載藥量均>2.90%，穩(wěn)定性良好。與Lip-180相比，Lip-120和Lip-60表現(xiàn)出更緩慢的釋放性能和更好的跨膜吸收速率。Lip-120及Lip-60的藥時曲線下面積（AUC_0-∞）分別是Lip-180的1.52和1.80倍，并且Lip-120與Lip-60的AUC_0-∞分別是維生素K₁注射劑（市售對照）的1.24與1.46倍。與低凝血酶原血癥模型大鼠比較，經(jīng)ig給藥Lip-180、Lip-120、Lip-60及維生素K₁注射劑后，PT顯著降低（P<0.001），凝血因子Ⅱ、Ⅶ、Ⅸ、Ⅹ水平均升高，其中，Lip-60作用最顯著，除給藥后6 h的凝血因子Ⅹ外，均差異顯著（P<0.05、0.01、0.001）。結(jié)論 聚乙二醇化VK₁脂質(zhì)體分布均勻，穩(wěn)定性高，釋放緩慢，口服生物利用度高，體內(nèi)促凝效果較好，優(yōu)選粒徑最小的Lip-60。

Objective To formulate and characterize the PEGylated Vitamin K₁ (VK₁) liposomes with different particle sizes, and investigate the corresponding pharmacokinetics and coagulation-promoting activity. Methods VK₁ liposomes with different particle sizes were prepared by thin film dispersion method. Particle size, polymer dispersion index (PDI) and Zeta potential were measured by Malvin particle size analyzer. The morphology was observed by transmission electron microscope. The stability of liposomes at 4℃ for one month and in phosphoric acid buffer solution (PBS, pH 6.8) and pH 1.2 aqueous solution within 48 h were investigated using particle size as index. The encapsulation rate and drug load were determined by ultrafiltration centrifugation. In vivo intestinal absorption model of rats was used to investigate intestinal absorption characteristics. Pharmacokinetic behavior of liposome in rats was investigated by ig administration. The contents of plasma coagulation factors II, V, VII and IX were detected by ELISA kit, and the prothrombin time (PT) was detected in rats with hypothrombinemia induced by warfarin sodium, to evaluat the effect of VK₁ liposomes (2 mg·kg^-1) with different particle sizes on promoting coagulation. Results Three kinds of VK₁ liposomes were prepared, termed as Lip-180, Lip-120 and Lip-60, with a uniform particle size distribution of (182.40±2.17), (114.38±0.60) and (68.42±0.73) nm, and Zeta potentials of (-27.67±1.58), (-22.93±1.81) and (-26.63±1.37) mV, PDI were 0.21±0.01, 0.12±0.00 and 0.17±0.01, respectively. Meanwhile, these as-formulated liposomes were uniformly spherical shape of good stability with a satisfied encapsulation efficiency of 90% and a drug loading capability of 2.90% of the drug load. Compared with Lip-180, the in vitro release and in situ intestinal perfusion results demonstrated that Lip-120 and Lip-60 achieved a superior release performance and transmembrane absorption rate. In consistence with the in vitro results, the area under the drug time curve (AUC_0-∞) of Lip-120 and Lip-60 were 1.52 and 1.80 times of Lip-180, respectively. Lip-120 and Lip-60 generated 1.24- and 1.46-fold higher bioavailability than commercial VK 1 solution. After oral administration, all of these liposomes and commercial solution were able to decrease plasma PT, and enhance the produce of coagulation factors II, V, VII and IX in warfarin-triggered anticoagulant rat models, where Lip-60 exerted the best procoagulant efficiency. Conclusion Pegylated VK₁ liposomes have uniform distribution, high stability, slow release, high oral bioavailability, and wonderful in vivo coagulation effect, and Lip-60 with the smallest particle size is preferred.

R943

國家自然科學(xué)基金項目（82003675）；安徽中醫(yī)藥大學(xué)培育項目（2020py04，2021py05）