Spectrophotometric Determination of Amoxicillin Trihydrate in Pharmaceutical Preparation

Abstract

A new, fast, and sensitive spectrophotometric analysis method has been modified to assess amoxicillin trihydrate drug traces in aqueous mediums. This method depends on the “oxidative coupling reaction” between the drug and the promethazine hydrochloride as a reagent in the presence of potassium persulfate as an oxidizing agent. The resulted purple product was absorbed in the visible region of ultraviolet at (517 nm) and soluble in distilled water with a stability duration of (70 min). the product followed Lambert-Beer law in a series of concentrations of (20 –50 µg/ml) and molar absorbance of (7255 L /mole.cm), the Sandel index was (0.057808 µg/cm) and a rational standard deviation that do not exceed (RSD %=1.03). The rational error was less than (RE2.5=%). The limit of quantitation was equal to (L.O.Q.= 7.746x10-6µg/ml), and the limit of detection was (L.O.D.= 2.334x10-7µg/ml). The correlation factor was (R=0.9993) and the evaluation factor (R2=0.9987). This method has been successfully applied on the assessment of the amoxicillin trihydrate in the pharmaceutical drug (Promox-500 mg).