FORMULATION DEVELOPMENT AND DISSOLUTION RATE ENHANCEMENT OF RILPIVIRINE BY SOLID DISPERSION SYSTEMS
Bharati Arali*, Anand Kumar Y., Mallikarjuna Setty C.
The aim of this study was to enhance the dissolution rate of rilpivirine (RPV) using solid dispersion systems. A
comparison between kneading and solvent evaporation method was also investigated. Solid dispersions of
rilpivirine were prepared using poloxamer 407 and HPC at 1:1 and 1:3 w/w ratios. Dissolution tests were
conducted and evaluated on the basis of cumulative percentage drug release and dissolution efficiency.
Physicochemical characterizations of the solid dispersions were carried out using Fourier transform infrared
spectroscopy, differential scanning calorimetry and powder X‑ray diffraction. Dissolution was remarkably
improved in both systems compared to pure rilpivirine (P<0.05). Physicochemical characterization results
suggested that rilpivirine existed in the amorphous form in the entire solid dispersion systems providing evidence
of improvement in dissolution. Formulations of rilpivirine solid dispersion systems prepared using poloxamer 407
by solvent evaporation method showed best dissolution profile and 1:3 were identified as an optimum
drug‑polymer weight ratio. Further optimised formulations were prepared as direct compression tablets and
evaluated for various parameters. The tablets were found to have desirable physical properties and showed good
stability over the period of 6 months at 400±20C/75%±5%RH and 50±30C. Thus the present study demonstrated that
poloxamer 407 as carrier and solvent evaporation technique is a highly effective strategy for enhancing the
bioavailability of poorly water soluble rilpivirine.
Keywords: Solid dispersion, rilpivirine, dissolution enhancement, poloxamer 407, HPC.
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