Enhancement of Loperamide Dissolution Rate by Liquisolid Compact Technique

Abstract

Purpose: The aim of present study was to improve the dissolution rate of poorly soluble drugLoperamide (LPM) by liquisolid compact technique. Methods: Liquisolid compacts of LPM were prepared using Propylene glycol (PG) as asolvent, Avicel pH 102 as carrier, Aerosil as coating material and Sodium Starch Glycolate(SSG) as superdisintegrant. Interactions between the drug and excipients were examined byFourier Transform Infrared (FTIR) spectroscopy. The dissolution studies for LPM liquisolidformulation, marketed product and pure drug were carried out in pH 1.2 HCl buffer asdissolution media. Results: Results confirmed the absence of chemical interactions between the drug andexcipients. From the solubility studies, it was observed the LPM was highly soluble in PGthereby it was selected as a solvent. The dissolution efficiency of LPM at 15 min wasincreased from 9.99 % for pure drug and 54.57% for marketed product to 86.81% for thetablets prepared by liquisolid compact technique. Stability studies showed no significantchange in percent cumulative drug release, hardness, disintegration time, friability and drugcontent for 3 months. Conclusion: Formulation F2 showed significant increase in dissolution rate compared to themarketed product at pH 1.2 where LPM is largely absorbed. Around 90% of the drug wasreleased from F2 in 30 min compared to the marketed product and it might be due to theincreased wetting and surface area of the particles. Hence, the liquisolid compact techniqueappears to be a promising approach for improving the dissolution rate of poorly soluble drug.

Keywords: Dissolution, Liquisolid compacts, Loperamide, Solubility