Objective     To study the in vitro release and intestinal absorption of pyridostigmine bromide liposome.      Methods     Pyridostigmine bromide liposome was prepared by reverse phase evaporation to detect its encapsulation and in vitro liposome release. An in vitro everted intestinal sac model was used to observe the intestinal absorption of liposome and measure the concentration of pyridostigmine bromide in intestine by RP-HPLC.      Results     The capsulation rate of liposome was 95.08%±4.02% and its 72 h cumulative release rate

was 51.81%±2.15%

indicating that liposome could significantly increase the absorption of pyridostigmine bromide in duodenum

jejunum

ileum and colon (P0.05). The apparent permeability coefficient (Papp) of pyridostigmine bromide solution and liposome in different intestinal segments was (1.41±0.73)×10

-5

cm/s，(2.21±0.62)×10

-5

cm/s，(2.13±0.27)×10

-5

cm/s，(1.30±0.79)×10

-5

cm/s and (1.53±0.38)×10

-5

cm/s，(2.67±0.55)×10

-5

cm/s，(2.39±0.42)×10

-5

cm/s， and (2.59±0.70)×10

-5

cm/s

respectively (P0.05).      Conclusion     Liposome release is delayed in in vitro medium

thus increasing the bioavailability of pyridostigmine bromide in vivo by its enhancing its permeability.