Normal and Reversed-Phase HPTLC Methods for Simultaneous Estimation of Telmisartan and Metoprolol Succinate in Pharmaceutical Formulation

Two simple precise normal-phase (Method I) and reversed-phase (Method II) HPTLC/densitometry method have been developed for simultaneous determination of telmisartan and metoprolol succinate in bulk and in combined tablet formulation. Method I was developed with aluminium plates precoated with silica gel 60F254S, and toluene : propanol : methanol : triethylamine (8 : 1 : 1 : 0.5 v/v) was used as as mobile phase. Method II was carried out using aluminium coated with RP-18 silica gel 60 F254S HPTLC plates using methanol : water : triethylamine (6 : 4 : 0.5 v/v) as mobile phase. Both analyses were scanned with a densitometer at 242 nm. In Method I, good separation and resolution of drugs were achieved with Rf values 0.45±0.02 (telmisartan) and 0.70 ± 0.02 (metoprolol), while in Method II, telmisartan and metoprolol showed Rf values 0.55 ± 0.02 and 0.41± 0.02, respectively. These methods can be used in routine pharmaceutical analysis.