A solid-lipid microparticle system containing budesonide was prepared. The solid-lipid system was studied in terms of morphology, particle-size distribution, crystallinity, thermal properties, aerosol performance and dissolution/diffusion release. In addition, the microparticle system was compared to conventional spray-dried crystalline and amorphous budesonide samples. The particle size distributions of the crystalline, amorphous and solid-lipid microparticles, measured by laser diffraction, were similar; however, the microparticle morphology was more irregular than the spray dried drug samples. The thermal response of the solid-lipid microparticles suggested polymorphic transition and melting of the lipid, glycerol behenate (at ~48°C and ~72°C). No budesonide melting or crystallisation peaks were observed (as was seen in the drug only samples) suggesting that the budesonide was integrated into the matrix. X-ray powder diffraction patterns of the crystalline and amorphous budesonide were consistent with previous studies while the solid-lipid microparticles showed two peaks, at approximately 21.3 and 23.5 2θ suggesting the metastable sub-α and primarily β’ form. Analysis of the in vitro diffusion/dissolution of the formulations was studied using a flow through model and the curves analysed using difference/similarity factors and fitted using the Higuchi model. Regression analysis of this data set indicated differences in the t0.5, where values of 49.7, 35.3 and 136.9 mins were observed for crystalline, amorphous and the solid-lipid microparticles, respectively. The aerosol performance (<5μm), measured by multistage-liquid-impinger, was 29.5% and 27.3%, 21.1% ± 0.6% for the crystalline, amorphous and the solid-lipid microparticles, respectively. This study has shown solid-lipid microparticles may provide a useful approach to controlled release respiratory therapy.

PREPARATION OF SOLVENT-FREE LIPID MICROPARTICLES AS SUSTAINED RELEASE SYSTEM FOR INHALATION

SCALIA, Santo;
2009

Abstract

A solid-lipid microparticle system containing budesonide was prepared. The solid-lipid system was studied in terms of morphology, particle-size distribution, crystallinity, thermal properties, aerosol performance and dissolution/diffusion release. In addition, the microparticle system was compared to conventional spray-dried crystalline and amorphous budesonide samples. The particle size distributions of the crystalline, amorphous and solid-lipid microparticles, measured by laser diffraction, were similar; however, the microparticle morphology was more irregular than the spray dried drug samples. The thermal response of the solid-lipid microparticles suggested polymorphic transition and melting of the lipid, glycerol behenate (at ~48°C and ~72°C). No budesonide melting or crystallisation peaks were observed (as was seen in the drug only samples) suggesting that the budesonide was integrated into the matrix. X-ray powder diffraction patterns of the crystalline and amorphous budesonide were consistent with previous studies while the solid-lipid microparticles showed two peaks, at approximately 21.3 and 23.5 2θ suggesting the metastable sub-α and primarily β’ form. Analysis of the in vitro diffusion/dissolution of the formulations was studied using a flow through model and the curves analysed using difference/similarity factors and fitted using the Higuchi model. Regression analysis of this data set indicated differences in the t0.5, where values of 49.7, 35.3 and 136.9 mins were observed for crystalline, amorphous and the solid-lipid microparticles, respectively. The aerosol performance (<5μm), measured by multistage-liquid-impinger, was 29.5% and 27.3%, 21.1% ± 0.6% for the crystalline, amorphous and the solid-lipid microparticles, respectively. This study has shown solid-lipid microparticles may provide a useful approach to controlled release respiratory therapy.
2009
Lipid microparticles; inhalation; controlled release; budesonide
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/1399526
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