Abstract:
The aim of present investigation was to improve the dissolution rate of the poorly
water soluble drug, nicardipine HCl by incorporating the drug in a liquisolid tablet.
Liquisolid tablets were prepared using propylene glycol as non-volatile solvent to
solubilze the drug. Avicel pH 102 and Aerosil 200 were selected as the carrier and
coating material respectively. Fourier transform infrared spectroscopy was performed
to study for drug-excipients incompatibility. Liquisolid tablet of nicardipine HCl was
prepared using directly compressible method. Optimization of formulation variables
was done using 32 factorial design using Design Expert software. Optimized batch
containing drug(Nicardipine HCl) concentration (30%w/w) and powder
excipients(Avicel pH 102 and Aerosil) ratio (30) was evaluated for pre-compression
parameters such as angle of repose, carr’s index, hausner’s ratio and post compression
parameters such as hardness, friability, weight variation, disintegration time, and drug
content. In-vitro drug dissolution was performed on dissolution apparatus (USP
paddle type-II) using 0.033 M citric acid buffer, pH 4.5 as a dissolution medium.
Stability study was performed at room temperature and accelerated condition. The
FTIR study confirmed absence of interaction between drug and excipients. The results
of pre-compression parameters such as angle of repose, carr’s index, and hausner’s
ratio were found to be 36.76º±0.35º, 20.62%±0.33%, and 1.25±0.020 which indicates
good flow property. Post compression parameters such as hardness, friability, weight
variation, disintegration time, drug content were found to be 4.0Kg/cm2±0.66Kg/cm2,
0.186%±0.02%, 393.8mg±0.63mg, 1.38min±0.010min, and 100.60%±0.66%
respectively for optimized batch. Higher percentage of drug dissolution for
nicardipine HCl was found up to 20 min from liquisolid tablet (92.10±0.57%) than the conventional directly compressible tablet (26.74%±0.246%). The result of stability
study showed that there is no major change in drug content and in vitro drug
dissolution. The present study demonstrated that, increase in the dissolution rate was
found to be significant compared to direct compressible tablet of nicardipine HCl. The
liquisolid technique appears to be a promising approach for improving the dissolution
of poorly soluble drugs like nicardipine HCl.
