Tea Tree Oil in Calcium Alginate Microparticles

Lorena Segale; Andrea Foglio Bonda; Lorella Giovannelli

Lorena Segale Department of Pharmaceutical Sciences, Universit� del Piemonte Orientale, Novara, Italy and APTSol Srls, Largo Guido Donegani 2/3, 28100 Novara, Italy.
Andrea Foglio Bonda Department of Pharmaceutical Sciences, Universit� del Piemonte Orientale, Novara, Italy and APTSol Srls, Largo Guido Donegani 2/3, 28100 Novara, Italy.
Lorella Giovannelli Department of Pharmaceutical Sciences, Universit� del Piemonte Orientale, Novara, Italy and APTSol Srls, Largo Guido Donegani 2/3, 28100 Novara, Italy.

Keywords: Tea tree oil, alginate, essential oil, microparticles, drying

Abstract

The aim of this work was the characterisation of tea tree oil calcium-alginate microparticles prepared using prilling vibration technology and drying according to three different methods (oven at 40C, dynamic drying under air-flow at 22C and freeze-drying). Microparticles were characterized by stereomicroscopy, scanning electron microscopy, thermogravimetric analysis and as regarding essential oil content and in vitro release. After oven drying and air-flow drying processes, microparticles were partially aggregated. They had a high oil content (more than 50% w/w) and were able to release tea tree oil in about 3 hours. Freeze-drying gave microparticles well separated to each other, characterized by the highest dimensions (about 500 m), a good essential oil content and the fastest release rate. For all systems, the oil content decreased during storage with a total loss, after 5 months, ranging from 10% (air-flow dried microparticles) to 24% (oven-dried microparticles).