Crystallographic investigation of cetylpalmitate solid lipid nanoparticles

Solid lipid nanoparticles (SLN) as alternative intravenous colloidal drug c arriers were produced by high pressure homogenisation of the melted lipid c etylpalmitate. The crystallographic properties of the used cetylpalmitate S LN were characterised by small angle X-ray scattering (SAXS) and X-ray diff raction (XRD). It was found that the SLN are available exclusively in a cry stalline form. Different cetylpalmitate formulations showed all the same pa tterns and a uniform crystal lattice was obtained. A partial indexing of th e signals of the cetylpalmitate was carried out and the unit cell of the ce tylpalmitate was estimated by the Miller indices. A preferred orientation i n 001-direction was observed. This can be explained by an impressive lamell ar lattice structure of the cetylpalmitate. The results were compared with the crystal data of cetylpalmitate known from literature. There was no corr elation with the monoclinic structure known so far. This could indicate tha t the SLN consist of crystallites of another modification of the cetylpalmi tate. (C) 2000 Elsevier Science B.V. All rights reserved.