Simultaneous Determination of Multicomponent Dosage Forms Using Benchtop NMR Spectroscopy: Application to Phenytoin-Phenobarbital Combination.

The use of nuclear magnetic resonance (NMR) spectroscopy as a tool for determining pharmaceutical molecules in bulk drugs and their dosage forms is growing. New advancements in benchtop NMR spectrometers with cryogen-free magnets have made this technique more appealing and accessible. Herein, we developed a method using a benchtop NMR spectrometer to quantify phenytoin (PhT) and phenobarbital (PhB) in bulk and combined dosage forms. The results were compared to those obtained by high performance liquid chromatography (HPLC) as a well-characterized procedure. This method is simple, low cost, relatively fast, and non-inferior to HPLC in terms of figures of merit.