FORMULATION DEVELOPMENT AND DISSOLUTION RATE ENHANCEMENT OF RILPIVIRINE BY SOLID DISPERSION SYSTEMS

Bharati Arali*, Anand Kumar Y., Mallikarjuna Setty C.

ABSTRACT

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.