Bioavailability Studies Of Andrographolide In Rats

摘要

Satu kaedah analisis kromatografi cecair prestasi tinggi yang mudah, sensitif and khusus telah dibangunkan dan disahkan untuk pengesanan dan kuantifikasi andrographolide di dalam plasma. Kaedah ini adalah linear dari 31.3ng/mL hingga 2000ng/mL. Nilai koefisi variasi untuk dalam hari dengan antara hari pengesahan adalah kurang daripada 12%. Nilai kejituan untuk dalam hari dengan masing-masing antara hari adalah di antara 90.3% - 103.3% dan 93.5% - 103.9%. Pemulihan mutlak untuk andrographolide adalah lebih daripada 67%. Andrographolide stabil dalam larutan sehingga 6 bulan. Walau bagaimanapun, ia hanya stabil dalam plasma sehingga 2 jam, mungkin kerana terikat kepada protein. Andrographolide tulen adalah kurang larut dalam air. Apabila dicampur dengan polimer polyvinylpyrrolidone (PVP) K25, kelarutan andrographolide dalam air meningkat. Penyelidikan in vitro menunjukkan bahawa kebolehlarutan andrographolide meningkat apabila jumlah PVP K25 ditambah. Kompleks andrographolide-PVP K25 adalah stabil pada pH1.2, 4.5 dan 7.0 sehingga 8 jam, dengan lebih daripada 90% kekal dalam larutan. Penyelidikan in vivo dalam tikus menunjukkan bahawa andrographolide tulen tidak dapat dikesan dalam plasma walaupun diberi dos setinggi 50mg/kg.ududA simple, specific and sensitive high performance liquid chromatography (HPLC-UV) analytical method has been developed and validated for detection and quantification of andrographolide level in the plasma. The standard curve was linear from 31.3ng/mL to 2000ng/mL. The coefficient of variation (C.V.) values of this method was less than 12% for both within- and between-day validation. The accuracy for both within- and between-day validation ranged from 90.3% to 103.3% and 93.5% to 103.9% respectively. The absolute recovery for andrographolide was more than 67.3%. Andrographolide in working solution was stable up to 6 months. Nevertheless, it was only stable in plasma up to 2 hours, probably due to high protein-binding. Pure andrographolide was poorly soluble in water. Its aqueous solubility increased when physically mixed with polymer polyvinylpyrrolidone (PVP) K25. In vitro studies showed that the solubility of andrographolide increased when increased amount of PVP K25 was added. Andrographolide-PVP K25 complex was stable in pH1.2, 4.5 and 7.0 up to 8 hours, with more than 90% remaining undegraded. In vivo rat studies showed that pure andrographolide was barely detected in plasma although given at high dose of 50mg/kg.