Preparation and in vitro evaluation of lipidic carriers and fillers for inhalation

The present study relates to compositions of solid lipidic microparticles (SLmP), composed of biocompatible phospholipids and cholesterol, and their use as carriers or as fillers delivering drugs directly to the lungs via a dry powder inhaler (DPI). SLmP were obtained by spray-drying and were formulated as lipidic matrices entrapping budesonide or as physical blends (drug carrier). They were developed in order to improve the delivery of the active drug by the pulmonary route. The SLmP were evaluated for their physical characteristics and in vitro deposition measurements were performed using the Multi-stage Liquid Impinger (MsLI). The Pulmicort Turbuhaler® DPI (AstraZeneca) was used as a comparator product.The SLmP appeared to be spherical low-density material characterized by a smooth surface. The mass median diameters (D(0,5)), and the volume mean diameters (D[4,3]) were tiny and ranged from 1,7 to 3,1 μm and from 2,0 to 3,9 μm, respectively. The SLmP formulations, delivered by the Cyclohaler® inhaler, were found to emit a fine particle dose (FPD) of 93–113 μg, which is very promising comparing to the FPD (68 μg) delivered by the Pulmicort Turbuhaler®.