Development and Validation of RP-HPLC and an Ecofriendly HPTLC Method for Simultaneous Determination of Felodipine and Metoprolol Succinate, and their Major Metabolites in Human Spiked Plasma.

BACKGROUND: Felodipine is a calcium channel blocker used together with metoprolol succinate for treatment of hypertension.

OBJECTIVE: Two chromatographic methods were developed for simultaneous determination of felodipine (FEL) and metoprolol succinate (MET), and their major metabolites, dehydrofelodipine and metoprolol acid, respectively.

METHODS: The first method was RP-HPLC which comprised separation of the studied components by gradient elution using a Phenomenex C8 column and a mobile phase composed of water (adjusted to pH 3.5 with o-phosphoric acid)-acetonitrile - methanol (45:40:15, by volume) for the first 6 min and (30:60:10, by volume) for the next 4 min at a flow rate of 1 mL/min followed by UV detection of the eluted peaks at 225 nm. The second method was an HPTLC method where separation was achieved using a mobile phase consisting of toluene-ethyl acetate-methanol-ammonia-formic acid (10:5:2.5:0.3:0.1, by volume) and scanning of the separated bands at 225 nm.

RESULTS: Validation of the developed methods was done according to ICH guidelines. Successful application of the developed methods was carried out for determination of the studied drugs in human spiked plasma and in Logimax® tablets.

CONCLUSIONS: The developed RP-HPLC and HPTLC methods can be further applied for quality control testing of the studied drugs.

HIGHLIGHTS: RP-HPLC and HPTLC methods for determination of FEL, MET and their major metabolites. The developed methods were successfully applied for determination of FEL and MET in Logimax® tablets.