Determination of Doxycycline hydrochloride Drug by Using of Manufactured Selective Membrane Electrodes


An accurate, sensitve, selective and reproducible method for quantification of Doxycycline hyclate(doxy) in pharmaceutical preparation has been developed. This method is based on construction of selective liquid membrane electrodes using phosphomolybdic acid (PMA) as an active material and either tir-n-butylphosphate (TBP) or di-n-butylphthalate (DBPh) as a plasticizer and and PVC as matrix for all electrodes.The results showed that the linear concentration is 10-4 –10-1 M for both electrodes, correlation coefficient, slope, limit of detection, optimum pH range and the life time were (0.9681and0.9595), (32.2and36.1 mV/decade), ( 1.0 ×10-6 and 8.0 ×10-7 M ), (1.5 - 1.8 and 1.5) and (14 and 11 days) for DOXY-PM+TBP and DOXY-PM+DBPh electrodes respectively . This method was successfully applied for the determination of (DOXY) in DOXYSAM Capsules with percentage recovery of not less than 97 % .