Abstract: ObjectiveTo develop solid lipid nanoparticles (SLNs) of penciclovir and evaluate potential of SLNs as a topical carrier for enhanced skin permeation of penciclovir. MethodsPenciclovir loaded SLNs were prepared with the W/O/W double emulsion technique. Its morphology was investigated by TEM. Zeta potential and particle size were evaluated. Entrapment efficiency and drug loading were determined, and thermal behavior was investigated by DSC. The in vitro skin permeation behavior was investigated with a marketed cream as a control. ResultsThe obtained SLNs were spherical, and mean size and Zeta potential of SLNs were (254.9±8.2) nm and (-25±0.05) mV. Entrapment efficiency of penciclovir in SLNs was (92.40±1.4)% and (4.62±0.2)% for drug loading. DSC study showed that penciclovir encapsulated in SLNs was in an amorphous form. Cumulative amounts of penciclovir from cream and SLNs at 12 h after dosing were (41.07±3.07)μg/cm2 and (88.44±4.19)μg/cm2. Microscopic pictures showed that interaction between SLNs and skin surface made morphology of the stratum corneum apparently changed and broke close conjugation of the corneocyte layers, which was possible reason of SLNs resulted in an increased permeation of penciclovir. ConclusionSLNs providea good skin permeation effect and may be a promising carrier for topical delivery of penciclovir.

Key words: Penciclovir, Solid lipid nanoparticle, Differential scanning calorimetry, Topical delivery, Grape seed proanthocyanidin extracts； ApolipoproteinA-Ⅰ； Rats, Wistar； aorta； Difference gel electrophoresis