Colorimetric determination of procainamide in injectable preparations

Area of Science:

• Analytical Chemistry
• Pharmaceutical Analysis

Background:

• Accurate quantification of pharmaceutical agents is crucial for patient safety and therapeutic efficacy.
• Procainamide is a widely used antiarrhythmic medication administered via injection.

Purpose of the Study:

• To develop and validate a simple, rapid colorimetric method for determining procainamide concentration in injectable solutions.
• To assess the method's accuracy and reliability for quality control of commercial procainamide formulations.

Main Methods:

• Complexation of procainamide with cupric ions.
• Spectrophotometric measurement of the resulting complex at 380 nm.
• Optimization of reaction conditions, including pH using an acetate buffer.

Main Results:

• The colorimetric reaction formed a 1:1 metal-drug complex.
• Optimal reaction pH was determined to be 4.0-4.5.
• Linear standard curves were achieved for concentrations ranging from 1.52 to 6.06 mg/mL.
• Analysis of 29 commercial samples showed an average recovery of 97.3% of the label claim.

Conclusions:

• The developed colorimetric method is simple, rapid, and accurate for quantifying procainamide in injectable solutions.
• This method provides a reliable tool for the quality control of pharmaceutical procainamide formulations.
• The high average recovery indicates good agreement between the method's results and the labeled drug content.