Der Pharmacia Lettre
Abstract
Author(s): Surjyanarayan Mandal, Snigdha Das Mandal, Naazneen Surti, Vandana B. Patel
Flunarizine, a piperazine derivative, is a selective Ca++ channel blocker coupled with its
antihistaminic property claimed to be effective in prophylaxis of migraine. Oral bioavailability
of flunarizine is very low (less then 18%) due to poor water solubility and extensive first pass
metabolism. The aim of the investigation was to design and develop microemulsion of
Flunarizine for enhancing its solubility hence the oral bioavailability. Solubility of flunarizine
was determined in various vehicles. Pseudo-ternary phase diagrams were constructed to identify
the microemulsion existing zone. Optimization of formulation was done by process and
formulation optimization. Optimized microemulsion was characterized for its transparency,
droplet size, zeta potential, viscosity, % assay, and stability study etc. Particle size and zeta
potential of optimized microemulsion were found to be 12.3 nm, -6.34 mV respectively. Drug
content of the microemulsion formulation was 98.29Ã?â??Ã?±0.91. The viscosity data indicated the
microemulsion to be O/W type. 78.49% and 71.53% of the drug was found to be released in 8hrs
in the in-vitro and ex-vivo studies respectively. Solubility of flunarizine was successfully
enhanced by 123 times by Capmul MCM microemulsion compared with distilled water
(pH=7.4). Hence, by formulating into microemulsion, the solubility of Flunarizine was
significantly enhanced which may increase its bioavailability.
