Effect of Lipophilicity of Dispersed Drugs on the Physicochemical and Technological Properties of Solid Lipid Nanoparticles

摘要

A series of aliphatic esters of the NSAID naproxen (NAP) were synthesised and encapsulated in solid lipidnanoparticles (SLN) to evaluate the influence of lipophilicity on drug loading and release, as well as physicochemicalproperties and stability of SLN.The lipophilicity of esters mainly showed to influence their affinity for the solid lipid matrix, modifying the drug releaseprofile compared to the parent drug, whereas drug encapsulation efficiency and the technological properties and stabilityof SLN were not affected. After storage at room temperature the in vitro release profiles of esters changed with respect tofreshly prepared systems, depending on the lipophilicity of the dispersed derivative. In particular, the SLN containing themedium-chain hexyl and octyl esters showed a 70-80% increase of drug release after storage; SLN loaded with NAP orthe lower ethyl and butyl esters did not show significant changes in the drug release rate.Such findings reveal that the affinity of NAP esters for the lipid network of the nanoparticles is strongly dependent ontheir lipophilicity and an excessive increase of the latter negatively influences the allocation and retention on these compoundsin the nanoparticles.