Kesarin Busaranon. Comparison of spectrophotometric method and high performance liquid chromatography for the analysis of flunarizine capsules. Master's Degree(Pharmaceutical Chemistry). Mahidol University. : Mahidol University, 2004.
Comparison of spectrophotometric method and high performance liquid chromatography for the analysis of flunarizine capsules
Abstract:
Flunarizine dihydrochloride is a difluorinated derivative of cinnarizine, which
is mainly used as a selective calcium channel blocker, and it may reduce the
frequency of either classical or common migraine attacks by as much as 90%.
However, this drug is not official in any pharmacopoeia and the reported analytical
methods are usually laborious and time consuming.
This study developed the simple spectrophotometric methods, both direct UV
and first derivative measurements, for the analysis of flunarizine dihydrochloride in
capsules. Suitable solvents for dissolving flunarizine were investigated. Methanol
was selected to be the solvent for flunarizine because it provided the highest
solubility and UV characteristics without interferences from a sample matrix in both
direct and first derivative measurements. The UV absorbance was both measured
directly and the first derivative was at 254 and 268 nm, respectively. The developed
methods were validated for their linearity, accuracy, precision, limit of detection
(LOD) and limit of quantitation (LOQ) compared with HPLC method. The
spectrophotometric methods illustrated excellent linearities (r 2> 0.9999) in the
concentration range of 6-24 μg/mL. Precisions were good (%RSD < 1.50).
Recoveries were good (%R > 99.62). The LOD of direct UV and first derivative
measurements were 0.0086 and 0.0835 μg/mL, respectively. The LOQ of direct UV
and first derivative measurements were 0.2606 and 2.5316, μg/mL, respectively.
The developed and validated methods were applied for determination of flunarizine
in commercial capsules and were found to be simple, fast, inexpensive and efficient.
Results from the spectrophotometric methods, both direct and first derivative
measurements were not significantly different from HPLC method (P = 0.05).