肺部给药是治疗呼吸道疾病的最佳给药方式，然而临床上使用的吸入制剂给药频次多，病人依从性差，因此需要开发肺部缓释制剂。然而，由于没有合适的载体和评价技术，目前并没有成熟的制剂技术能够实现肺部缓释。

针对聚合物高分子材料肺部不相容，可使用辅料较少的现状，我们选择了布地奈德、环索奈德和丙酸氟替卡松作为模式药物，选择微米晶和纳米晶的制剂形式，进行体内外一致性评价的探索。选择不同粒径的鱼腥草挥发油固体脂质纳米粒和纳米晶混悬液一起，进行可吸入性的比较。

本文首先建立了三种可吸入性糖皮质激素的体内外含量测定方法。以湿法球磨和高压均质的方法制备了环索奈德和丙酸氟替卡松纳米晶和微米晶混悬液，并对丙酸氟替卡松纳米晶进行了磷脂修饰。以Spraytec和NGI评价了五种化合物的可吸入性，以改进的Transwell溶出装置测其体外溶出。微米晶和纳米晶混悬液大鼠肺部给药后，测其肺泡灌洗液、肺组织、肠组织和血中的药物含量。其中肺泡灌洗液中含量代表药物未溶出的药物含量，肠组织中的药物含量代表清除到肠道的药物含量，血中代表吸收进入系统循环的药物含量。

实验结果表明，以肺泡灌洗液中药物含量代表药物在肺内的溶出和体外溶出具有一定的关联性。环索奈德微米晶可以实现在肺部的长时间驻留。纳米晶制剂可以减少肺部纤毛清除，提高肺部生物利用度。磷脂修饰的纳米晶可以减少肺部纤毛清除，提高药物在肺部的有效生物利用度，其有效生物利用度是纳米晶的1.7倍，是微米晶的4.2倍。

首先，本文建立了布地奈德、环索奈德和丙酸氟替卡松的体外含量的HPLC测定方法，和灵敏度高的体内含量LC-MS/MS测定方法。布地奈德的内标化合物为曲安奈德，用乙酸乙酯液-液萃取法作为样品前处理方法，环索奈德和丙酸氟替卡松的内标化合物为米非司酮，用叔丁基甲醚液-液萃取法作为样品前处理的方法。结果显示，方法绝对提取回收率在85%以上，具有良好的准确度和精密度，没有明显的基质效应，达到生物样品测定的要求。

其次，本文联合应用平行星式球磨和高压均质法，制备了环索奈德和丙酸氟替卡松的微米晶混悬液和纳米晶混悬液，表征了微米晶和纳米晶的粒径、电位和放置稳定性。结果表明，微米晶混悬液在室温下放置一年后粒径基本无变化，纳米晶混悬液可保持3个月的稳定性。采用纳米晶溶液水化脂质薄膜的方法，制备了磷脂修饰的丙酸氟替卡松纳米晶混悬液，透射电镜表征其形态和包封情况，结果表明，纳米晶被磷脂均匀包裹，载药量为12.5%。本文采用自制的Transwell溶出装置，表征了6种制剂的体外溶出性质。结果显示，布地奈德和环索奈德在2 h内溶出曲线已达平台期，释放高达85%，丙酸氟替卡松可持续释放至12 h，纳米晶的溶出速度均快于相应药物的微米晶，而磷脂修饰的丙酸氟替卡松在12 h内只溶出了53.6%±4.0%。说明丙酸氟替卡松为溶出限速型化合物，经过磷脂修饰后，进一步降低其在体外的溶出速率。

第三，本文表征了市售布地奈德混悬液、环索奈德微米晶和纳米晶混悬液和丙酸氟替卡松微米晶和纳米晶混悬液的可吸入性。选用德国PARI BOY SX型压缩雾化器压缩雾化器和PARI LC PLUS型号药杯，采用Spraytec实时监测雾化过程中雾滴的粒度变化，采用药典规定的NGI装置，对5种雾化液进行可吸入性评价。结果显示，采用此装置的布地奈德、环索奈德和丙酸氟替卡松微米晶混悬液雾化的MMAD分别为6.41±0.35 μm、5.97±0.05 μm和6.02±0.12 μm，环索奈德和丙酸氟替卡松纳米晶混悬液雾化的MMAD分别为5.08±0.18 μm和5.43±0.14 μm。

第四，本文应用已建立的LC-MS/MS分析方法，研究了此6种微米晶和纳米晶混悬液经大鼠气管滴注肺部给药后，大鼠体内的药代动力学以及肺泡灌洗液、肺组织和肠组织中的药物分布。结果表明，微米晶药物肺泡灌洗液中环索奈德的代谢物和丙酸氟替卡松最长可检测到4 h，布地奈德仅在1 h可检测到；肺组织中，丙酸氟替卡松和布地奈德可检测到12 h，环索奈德的代谢物在24 h可检测到少量；肠道中1 h药物含量较高，表明微米晶大量被纤毛清除至消化道。血中药物浓度，布地奈德可检测到1.5 h，环索奈德及其代谢产物可检测到2 h，丙酸氟替卡松可检测到 4 h。纳米晶药物肺泡灌洗液中环索奈德的代谢物在4 h内可检测到，丙酸氟替卡松可检测到8 h；磷脂修饰的丙酸氟替卡松纳米晶在24 h时仍能检测到少量。肺组织中，两种纳米晶和磷脂修饰的丙酸氟替卡松24 h内均可检测到；肠道中的药物含量和微米晶相比有所减少。血中药物浓度，环索奈德及其代谢产物可检测到4 h，丙酸氟替卡松可检测到 8 h，磷脂修饰的丙酸氟替卡松纳米晶可检测到12 h。

总而言之，本文成功制备了环索奈德和丙酸氟替卡松的微米晶和纳米晶混悬液以及磷脂修饰的丙酸氟替卡松纳米晶混悬液。对此5种混悬液和市售布地奈德混悬液进行了体内外评价，通过体外溶出特性区分了药物的溶出特性，揭示了其药代动力学特性和肺泡灌洗液、肺组织和肠道中的药物含量，并进行了比较分析。磷脂修饰的纳米晶显示出较优的肺部缓释特性。

Pulmonary delivery is the best way to treat respiratory tract diseases. However, the inhaled drugs used in clinic are frequently administered and patients are poorly treated. Therefore, it is necessary to develop a lung sustained-release formulation. However, due to the absence of appropriate vectors and evaluation techniques, there is currently no mature formulation to achieve lung release.          

For the poor compatibility status of polymer material in lung, we chose the ciclesonide and budesonide, fluticasone propionate as model drug, to prepare micron grained and nanocrystalline formulation. The volatile oil of Houttuynia cordata Thunb with different particle size, solid lipid nanoparticles and nano crystal suspension were selected to compare the inhalable properties.         

In this paper, methods for determination of inhaled glucocorticoids in vivo and in vitro were established. With the method of wet milling and high-pressure homogenization for ciclesonide and fluticasone propionate in nanocrystalline and microcrystalline suspension was prepared. At last, we modified fluticasone propionate nanoparticles with phospholipid. The inhalable properties of five compounds were evaluated by Spraytec and NGI, and their dissolution in vitro was evaluated by an modified Transwell dissolution device. The content of drugs in bronchoalveolar lavage fluid, lung tissue, intestinal tissue and blood was measured after administration of micron and nano crystalline suspension in lungs of rats. Among them, the content of bronchoalveolar lavage fluid represents the insoluble content of the medicine. The content of the drug in the intestinal tissue represents the content of the drug which clears to intestine, and the blood represents the content of the drugs absorbed into the systemic circulation.          

The results showed that the content of drugs in bronchoalveolar lavage fluid was related to the dissolution of drugs in the lungs. Ciclesonide micro crystal achieved a long-time resident in the lungs. Nanocrystals can reduce lung mucociliary clearance and improve lung bioavailability. Phospholipid modified nanocrystals can reduce lung mucociliary clearance and improve the bioavailability of the drug in the lungs, and its bioavailability is 1.7 times of that of nanocrystals and 4.2 times of that of micron crystals.