Background: The drug cinnarizine is used in the treatment of vertigo and migraine. The
main drawback is its very low water solubility which causes unpredictable bioavailability. Solubility
is better in acidic pH. Therefore, gastro-retentive formulation would be beneficial to improve the
bioavailability of the drug.
Objective: The objective of the study was to prepare floating microballoons of cinnarizine which
would float in the gastric fluid and release the drug in a sustained manner.
Methods: Microballoons were prepared by diffusion solvent evaporation technique using polymers
(Eudragit® S100, Eudragit® RLPO, Eudragit RL®100), characterised by FTIR, XRD, DSC and optimized
by sequential simplex design. For optimization, formulations were graded with respect to
formulation efficiency (percentages of yield, sphericity and drug content) and performance index
(buoyancy and dissolution efficiency), from which the overall response of the formulations was
determined. Finally, the optimized formulation was radiolabelled with 99mTc-MIBI and fed to Wistar
albino rats and was evaluated for gastric retention by gamma scintigraphic study.
Results: FTIR studies indicated drug and polymers were compatible. DSC and XRD analysis confirmed
that the drug was in amorphous state in the formulation. SEM studies confirmed the sphericity
of the microballoons. Formulation N7 showed the best overall response (65.61) which was the
nearest to the target. Gamma scintigraphic study confirmed that the formulation was retained in the
stomach for more than 5 h.
Conclusion: The results indicated that floating microballoons of cinnarizine would stay in the
stomach for prolonged period and thereby improve the bioavailability of the drug.