Coprecipitation of Polyvinylpyrrolidone/β-Carotene by Supercritical Antisolvent Processing

Abstract

Production of coprecipitated microparticles is an ambitious application of supercritical antisolvent precipitation (SAS). In this work, coprecipitates of β-carotene (BC) and polyvinylpyrrolidone (PVP) have been successfully obtained using this technique. Nanostructured microparticles in the range 1–2.4 μm were obtained, varying the polymer molecular weight (10 000 and 40 000 g/mol), the polymer/drug ratio (from 10/1 to 20/1), the operating pressure (from 85 to 100 bar), and the total concentration in the liquid solution (from 3 to 7 mg/mL). In particular, at 85 bar, 40 °C, 5 mg/mL, with a PVP/BC equal to 10/1, and using the polymer with the lower molecular weight, well-defined coprecipitated microparticles were obtained. Particles produced operating at these conditions showed a vitamin dissolution rate 10 times faster than the one of unprocessed BC, confirming the effective coprecipitation, and the increase of the β-carotene dissolution rate. The precipitation process and the mechanisms involved are also ...