Studies On Determinations Of Dihydroartemisinin And Piperaquine Phosphate In Compound Tablets And On The Test Of Aconitine In Shangshiqutong Plasters

OBJECTIVE:Compound tablets of Dihydroartemisinin and Piperaquine Phosphate are a new type of antimalarial drug. In Chinese current drug specification, DHA was determined by UV specterphotometry after basic hydrolysis. PQP was assayed with UV specterphotometry directly. However, there were much analytical errors in the two determinations. This research focuses on establishing sensitive and accurate HPLC-UV methods for determinations of DHA and PQP in compound tablets.Shangshiqutong Plasters are compound plasters made of Chinese traditional medicine Chuanwu, Caowu and so on. The plasters are an acesodyne. Chuanwu and Caowu contain Aconitine. Whereas it is virulent, Aconitine in Shangshiqutong Plasters was not tested in Chinese current drug specification. To establish TLC method for testing Aconitine in the compound plasters was another objective of this research.METHOD:Determination of DHA in Compound tablets: A Phenomenex C18 column (250mm×4.6mm, 5μm) was used. Mobile phase was acetonitrile - methanol - 0.02mol·L^-1 ammonium sulfate (50 : 10 : 40), adjusted to pH 4.8 with dilute sulphuric acid. Flow rate was 1.0 mL·min^-1, detection wavelength was 210 nm, column temperature was 30℃, and injection volume was 10μl. Theoretical plates forα-DHA orβ-DHA were no less than 10000.Determination of PQP in Compound tablets: A phenomenex C18 column (250mm×4.6mm, 5μm) was used. Mobile phase was acetonitrile - 0.022mol·L^-1 hydrochloric acid (30 : 70), adjusted to pH 2.3 with triethylamine. Flow rate was 1.0 mL·min^-1, detection wavelength was 225 nm, column temperature was 30℃, and injection volume was 10μL. Theoretical plate for PQP was no less than 2000.Test of Aconitine in Shangshiqutong Plasters: Mobile phase was n - hexane - ethyl - acetate - anhydrous - alcohol (6.4 : 3.6 : 1). Colorant was dilute bismuth potassium iodide.RESULTS:Determination of DHA in Compound tablets: Recovery was 98.6%. RSD of precision was 0.49% ( n = 5). LOQ was 80 ng (S/N = 10). Linear range was 0.84 25.12μg, linear regression equation was A = 29987c + 1006.6,γ= 0.9999 (n = 7). Sample solutions were stable in 8 h.Determination of PQP in Compound tablets: Recovery was 101.3%. RSD of precision was 0.41% (n = 6). LOQ was 90 ng (S/N = 10). Linear ranges was 0.20 1.21μg, linear regression equation was A = 525092c + 36071,γ= 0.9998 (n = 5). Sample solutions were stable in 8 h.Test of Aconitine in Shangshiqutong Plasters: The spot of Aconitine was separated from other spots completely. The colors of spots were stable.