應用HPLC方法測定Cefadroxil原料藥及其製劑之力價

DETERMINATION OF CEFADROXIL PREPARATIONS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

本研究旨在發展出一套簡單、迅捷且具特異性之高效液相層析法，以應用於鑑別及測定Cefadroxil之原料藥及其製劑（包括膠囊、口服懸液用粉劑）之力價：本法所使用之層析管為μ-Bondapak(TM) C18 並以Acetonitrile和O.1M磷酸鹽緩衝溶液（60：40）之混合液為移動相，Dimethy lphthalate為內部對照標準品，而於254nm波長處以紫外光偵測器測之。於本實驗中當Cefadroxil濃度範圍為0.02～0.8mg/ml時，所求得之標準曲線（Standard curve） 線性迴歸方程式為 X = 0.0881298 Y - 0.0000289，相關係數r=0.9999。本法所能偵測之最低限量為25ng。添加不同量之Cefadroxil於市售檢體（膠囊、口服懸液用粉劑）中，所得的平均回收率均在100.56%以上。重覆注射同一濃度之Cefadroxil標準品溶液，所測得Within-day之精確度為0.48%, 0.36%, 0.45%, 0.64%, 0.65%, 0.47%；Between─day之精確度為0.71%，顯示本法再現性（Reproducibility）極高。為得知本HPLC法是否可取代微生物法測定Cefadroxil製劑之力價，Cefadroxil各製劑同時以二種方法作配對實驗測定力價，並用Pairedt test作配對比較。結果發現，於99%可信度範園（Confidence level）內，原料藥、膠囊、口服懸液用粉劑同時以二種方法測定所得之力價並不具統計之差異。亦即HPLC法似可用以取代微生物法測定Cefadroxil原料藥及市售各製劑之力價。

A reverse-phase liquid chromatographic method was developed for the assay of cefadroxil in bulk drug and pharmaceutical preparations. The samples were analyzed on a pBondapak (C18) column with a mobile phase of acetonitrile and 0.01M potassium phosphate at a flowrate of 1.0 ml / min and UV absorbance detection at 254 nm. Equation was presented for linear relationship between peak area ratios of cefadroxil to dimethylphathaJate (internal standard) and the cefadroxil concentration over a range of 0.02-0.8 mg / ml (r=0.999). The detection limit was 25 ng. Standard addition recoveries ranged from 97.89% to 101.44% (mean 99.92%, n=18) for capsules and from 99.38% to 105.85% (mean 102.86%, n=5) for powders for oral solution. Both the within-day precision (C.V. of 0.36% to 0.65%) and the between-day precision (C.V. 0.71%) were satisfactory. Furthermore, different formulations from, fifteen manufactures were also assayed by the two analytical methods. At the 99% confidence level, no significant intermethod differences were noted for the assay results for each pair. The results indicated that the reverse-phase liquid chromatographic method is a suitable substitute for the microbiological method for potency assays of cefadroxil preparations.