ORIGINAL ARTICLES   

Minerva Biotecnologica 2007 March;19(1):1-5

Copyright © 2007 EDIZIONI MINERVA MEDICA

lingua: Inglese

Oral delivery of drugs by means of solid lipid nanoparticles

Silva A. C. ^{1, 2}, Santos D. ¹, Ferreira D. C. ¹, Souto E. B. ²

¹ Department of Pharmaceutical Technology Faculty of Pharmacy University of Porto, Porto, Portugal 2 Department of Pharmaceutical Technology Faculty of Health Sciences Fernando Pessoa University, Porto, Portugal

Aim. Oral drug delivery can be improved through nanoencapsulation of drugs into lipid carriers. This approach takes advantages of the fact that lipids have absorption promoting properties both for lipophilic and hydrophilic drugs. Thus, if problematic drugs, e.g. poorly soluble molecules such as ibuprofen, are incorporated into lipid carriers, bioavailability of such drug molecules might be improved. In the present paper lipid based carrier systems (i.e. solid lipid nanoparticles, SLN) composed of well tolerated lipids have been produced and physicochemically characterized.
Methods. The suitability of SLN to deliver ibuprofen for oral route has been assessed by means of particle size analysis. Cetyl palmitate-based SLN stabilized with a nonionic surfactant have been produced by high pressure homogenization.
Results. The mean particle size of drug-free and drug-loaded SLN was 230 and 312 nm, respectively. Nonetheless, microparticles have been measured by laser diffractometry in the ibuprofen-loaded SLN formulations. Aqueous drug-free SLN dispersions have been transformed into powders by lyophilization. Scanning electron microscopy revealed spherical-like shape SLN which was maintained after freeze-drying, however with some particle aggregation. Recrystallinity index of SLN was approx. Sixty percent before and after lyophilizing the samples, and the obtained powders showed good flow properties applying the tap density test with a Carr’s index of 13.
Conclusion. This paper reviews several analytical methodologies to characterize the dispersions in order to predict their long-term stability and suitability for oral delivery of model drugs.