Modified Rose Bengal assay for surface hydrophobicity evaluation of cationic solid lipid nanoparticles (cSLN)

• Published in: European journal of pharmaceutical sciences Vol. 45; no. 5; pp. 606 - 612
• Main Authors: Doktorovova, S., Shegokar, R., Martins-Lopes, P., Silva, A.M., Lopes, C.M., Müller, R.H., Souto, E.B.
• Format: Journal Article
• Language: English
• Published: Kindlington Elsevier B.V 11-04-2012; Elsevier
• Subjects: Adsorption; Biological and medical sciences; Cations - chemistry; Drug Carriers - chemistry; General pharmacology; Hydrophobic and Hydrophilic Interactions; Lipids - chemistry; Medical sciences; Nanoparticles - chemistry; Particle Size; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Rose Bengal; Rose Bengal - chemistry; Solid lipid nanoparticles; Surface hydrophobicity; Surface Properties; RB; SLN; Adsorption; Kb; Surface hydrophobicity; cSLN; Solid lipid nanoparticles; Rose Bengal; Assay; Evaluation; Pharmaceutical technology; Cations; Hydrophobicity
• ISSN: 0928-0987; 1879-0720
• DOI: 10.1016/j.ejps.2011.12.016

Surface hydrophobicity of nanocarriers influences protein binding and subsequently fate of nanoparticles in blood circulation. Therefore, characterization of surface hydrophobicity of nanocarriers provides important preclinical information. Here, a modified classical adsorption method for the needs of characterization of cationic solid lipid nanoparticles (cSLN) was developed. We have identified possible method limitations that should be considered when performing the analysis, i.e. the problems associated with particle separation from the dispersion and their own absorbance in visible spectrum. We propose two modified methods for performing the assay overcoming the stated limitations. We also discuss here evaluation by different approaches (calculation of binding constants or partitioning quotient) and their suitability for the prepared cSLN formulation. Overall, we confirmed that our modified adsorption method can provide useful information about surface properties of (cationic) SLN, however, performing and evaluation of the assay need special attention in order to obtain the desired results.