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t);多肽、蛋白酶(主要是氨肽酶); ? calcitonin, oxytoxin, LHRH, growth hormone, interferone, vaccines; ? 分子量 up to 2 KDa: pharmacologically acitive; ? 血腦屏障: IGF1。 Inhalation administration ? Ease of administration ? large surface area (75 m2) ? High vascularity ? Bypass of firstpass metabolism ? Insulin for Type II diabetes ? Dornasealpha for cyctic fibrosis ? Proteases in the lung ? Local effects ? Effect of molecular weight? Plasma bioavailability of therapeutic peptides versus MW after pulmonary administration Oral administration ? Generally not therapeutically active。 ? Factors for lack of systemic bioavailability: ? high gastrointestinal enzyme activity ? gastrointestinal mucosa as an absorption barrier。 ? cytochrome P450 3A and pglycoprotein activity ? Available oral forms: cyclosporine (30%) and desmopressin (%)。 ? Absorption enhancers。 encapsulation in microparticles or nanoparticles. 蛋白肽類藥物的分布 ? 分布容積?。? L/kg vs. 120 L/kg(小分子 )。 ? 分子量大 。 ? 水溶性大 。 ? 蛋白結(jié)合率高? ? 中央室( Vc):38 L=plasma volume和平衡室(Vss):1420 L2x中央室 。 ? 蛋白結(jié)合 : reduce clearance。 ? Sitespecific and targetoriented receptor mediated uptake 蛋白肽類藥物分布:血腦屏障 ? 血腦屏障: ?缺乏特異轉(zhuǎn)運(yùn)系統(tǒng); ?存在蛋白分解酶; ?外排作用泵 ? 提高 血腦屏障 對(duì)蛋白多肽類藥物攝取的方法: ?脂質(zhì)體 ?鼻腔給藥; ?脊髓管灌注或泵連續(xù)輸注。 Ziconotide cerebrospinal CSF concentration as a function of time CSF Ziconotide Pharmacokiic Res