The following project aims to produce a sensitive, high-precision and fast spectroscopic method. and cost-effective estimate for the determination of doxycycline hydrochloride in pharmaceuticals preparations), the reaction of Diazotization and coupling , The proposed approach is based on the creation of dyzonium salt by the reaction of In an acidic media, the ortho-anisidine reagent is combined with nitrite before being coupled with doxycycline hydrochloride in an alkaline medium to create a Yellow dye with the highest absorption at 437 nm , a calibration curve within Beer's law and concentration (1-60 μg.ml-1) with a correlation coefficient of 0.9998 of doxycycline hydrochloride, the detection limits were 0.379 (LOD) and 1.26 (LOQ), the Sandell’s sensitivity was 0.044 µg.cm-2, and the molar absorptivity was 10.72 x 103 l/mol.cm, relative standard deviation whose value not exceed 0.430 % and the recovery value not less than 99.96%, The method has been applied to pharmaceutical products. in several forms of doxycycline showed that the proposed method has good results within the acceptable error, The validity of the proposed method was proved by a recovery investigation Using the standard addition method. the validated approach is appropriate and extremely helpful for routine quality control of doxycycline hydrochloride since it does not require polluting reagents and is quick and inexpensive.
Shakir et al. (Mon,) studied this question.