本局於七十八年度委展出一種高效液相層析法，可用於鑑別及測定Cloxacillin原料藥及其製劑之力價，簡單、迅捷且具特異性。使用μ-Bondapak C18為層析管，以甲醇與4%醋酸(60:40)之混合液為移動相，dimethylphthalate為內部標準品，於254nm波長處以紫外光偵測器測之。由於同時於HPLC法與微生物法作配對實驗測定力價，並用pairedt test作配對比較，結果證明Cloxacillin原料藥及其製劑以二種方法測定所得之力價並不具統計上之差異。亦即HPLC法可用以取代微生物法來測定Cloxacillin各製劑之力價。故本實驗乃應用此HPLC方法於市售三家不同廠牌Cloxacillin膠囊製劑之品質管制。包括容量均一度(Content uniformity)，模擬處方試驗(Recovery)及溶離度試驗(Dissolution test)等。其結果均將於本文中討論。

A reversed phase high performance liquid chromatographic method has been developed for the assay of cloxacillin. The samples were analysed on a μ-Bondapak (C18) column with a mobile phase consisting of methanol and acetic acid. Our previous study has shown that this method is a suitable substitute for the microbiological method for potency assays and stability studies of cloxacillin preparations. The assay was also applied success-fully to three different commercical brands and proved to be free of interference from excipients normally used in formulations. The contents of uniformity and dissolution rates in different brands were performed. The results have shown that this analytical method could be utilized readily for routine quality control of cloxacillin pharmaceuticals, since it offers a simple system and short analytical time coupled with reproducibility and accuracy.