A Safety/Efficacy Study of Alprostadil Liposomes for Injection to Treat Lower Extremity Arteriosclerosis Obliterans

Inclusion Criteria: * An established clinical history of Atherosclerotic Occlusive Disease of the Lower Extremities in accordance with the definition by Chinese Medical Association(2015). * Age\>40 * Atherosclerotic Occlusive Disease of the Lower Extremities diagnosis * Arterial ischemia of the lower extremities pulsation has been weakened or disappeared. * Ankle brachial index(ABI) less than or equal to 0.9 * Diagnosis of artery stenosis or occlusion with imaging tests,including Doppler ultrasonography,CT angiogram(CTA),magnetic resonance angiography (MRA) or digital subtraction angiography(DSA) within 1 month prior to Screening. * Fontaine stage classification:Stage II * Distance of asymptomatic disease and claudication between 50m to 800m(The treadmill setting:pace at 3 km/h,incline at 12%).Subjects have intermittent claudication twice within 1 week prior to enrollment visit(Baseline is defined as the first measurement.Change from baseline in P-values less than or equal to 25%). * Age:80 years old or younger. * Intermittent claudication has been in stable condition in the last 6 months.And there was no history of exacerbations within 3 months prior to enrollment visit. * Informed Consent:A signed and dated written informed consent prior to study participation. Exclusion Criteria: * Subjects who have cardiac disease including caradiac failure,arrhythmias,coronary disease,mitral or aortic stenosis.Subjects with a recent history of myocardial infarction within the past 6 m…