Nanomedicine Journal

Nanomedicine Journal

Rilpivirine-loaded solid lipid nanoparticles: preparation, characterization, and in vivo evaluation for enhancing oral bioavailability

Document Type : Research Paper

Authors
Mangesh Bhalekar
Ashwini Madgulkar
Aditi Pande
Chetashri Patil
Maryam Sadik Mulla
Department of Pharmaceutics, AISSMS College of Pharmacy, Pune, India
10.22038/nmj.2026.86737.2190
Abstract
Objective(s): This study aimed to improve the oral bioavailability of Rilpivirine by creating and testing Rilpivirine solid lipid nanoparticles (SLNs) to determine the impact of drug delivery on pharmacokinetics following oral treatment in Wistar rats.
Materials and Methods: Solid lipid nanoparticles (SLNs) were fabricated using a high-pressure homogenization technique, after which they were evaluated for their physicochemical properties including particle size, morphology, zeta potential, encapsulation efficiency as well as their in vitro release behaviour, ex vivo permeability, and in vivo pharmacokinetics in Wistar rats. To further understand how SLNs are taken up through the lymphatic system, an ex vivo study was carried out using an everted rat intestinal sac model.
Results: The resulting SLNs were spherical, showing an average particle size of 74.45 ± 0.84 nm with a PDI of 0.27, zeta potential -17.49 ± 0.82 mV, and an entrapment efficiency of 62.9 ± 1.2%. The SLN formulation demonstrated 84% drug release over a 24-hour period. In an ex vivo study using everted rat intestine, the SLN's apparent permeability was 34.2 × 10-6 at 37 ± 0.5 °C without chlorpromazine. This value decreased to 14.6 × 10-6 when chlorpromazine was present. Pharmacokinetic studies in rats showed the SLN formulation's AUC was 1.04 times higher than that of the pure drug suspension. Conversely, adding the lymphatic uptake inhibitor chlorpromazine reduced the SLN's AUC by 0.52-fold. The in vivo pharmacokinetic data was assessed by Dunnett's test, which indicated a significant difference (p < 0.05) between the RLV SLNs and the plain RLV drug.
Conclusion: Employing SLNs as a delivery vehicle appears to be a viable method for boosting the therapeutic efficacy of rilpivirine. A key reason is that SLN lymphatic uptake is important for avoiding hepatic first-pass metabolism.
Keywords
Rilpivirine
Bioavailability
Lymphatic uptake
Solid lipid nanoparticles
Permeability
Solubility
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Nanomedicine Journal
Volume 13, Issue 3
Summer 2026
Pages 442-454