Preparation Of Composite Decompression Tablets And The Discussion Of Determination Of Its Content

This paper introduces a kind of compound medicine for hypertension, made of two chemical synthetical medicines, hydrochloric clonidine and hydrochlrothiazide.The content of hydrochloric clonidine is 0.025mg per piece and has been checked. In Chinese pharmacopoeia, the content of hydrochloric clonidine may be 0.075mg per piece and be checked by the method of non-aqueous titration. But the content of the newly produced medicine is 0.025mg per piece, much less than 0.075mg per piece in Chinese pharmacopoeia. Through the analysis of the data and the calculation, we found that the method of non-aqueous has many defects,such as big specimen, small volume,obvious error and so on.So we changed it into the ultraviolet spectrophotometer method. When we measured the content of clonidine hydrochloride, in citric acid-disodium hydrophospate buffer solution at pH value of 4.0, clonidine hydrochloride reacted with bromophenolum coeruleum to get yellow ion pair and then chloroformum was used to extract the ion pair. At last we used standard curve method to measure the content. When this method was applied to measure the content of chonidine hydrochloride, the linear relation was obvious. Before the content of hydrocholrothiazide was measured, the hydrocholrothiazide, which had been hydrolyzed by sodium hydroxide and diazotized, reacted with N- (Naphthyl)-aethylenediamini dihydrochloridum to form rose Bengal compound. The content of hydrocholrothiazide was measured using ultraviolet spetrophotometry too. When standard curve method was applied to measure the content of hydrocholrothiazide, the linear relation was also obvious. Using ultraviolet spetrophotometry instead of non-aqueous titration to measure the content of clonidine hydrochloride and hydrocholrothiazide could give satisfactory results. It supplies the foundation for the setting of quality standard of composite decompression tablets.