Electrochemical Determination of Dihydrocodeine in Pharmaceuticals

Abstract

Two analytical methods for the quality control of dihydrocodeine in commercial pharmaceutical formulations have been developed and compared with reference methods: a square wave voltammetric (SWV) method and a flow injection analysis system with electrochemical detection (FIA-EC). The electrochemical methods proposed were successfully applied to the determination of dihydrocodeine in pharmaceutical tablets and in oral solutions. These methods do not require any pretreatment of the samples, the formulation only being dissolved in a suitable electrolyte. Validation of the methods showed it to be precise, accurate and linear over the concentration range of analysis. The automatic procedure based on a flow injection analysis manifold allows a sampling rate of 115 determinations per hour.

Keywords:

• Dihydrocodeine
• Square wave voltammetry
• Flow injection analysis with electrochemical detection
• FIA

Acknowledgments

We thank Knoll Lusitana (Prior Velho, Portugal) for the generous gift of dihydrocodeine. One of us (J.M.P.J.G.) would like to thank the PRODEP Program for a Ph.D. grant.