LAUSR

Human Immunodeficiency Virus (HIV) is a global health concern to which nanomedicine approaches provide opportunities to improve the bioavailability of existing drugs used to treat HIV.In this article, lipid polymer hybrid nanoparticles (LPHNs) were developed as a system to provide a combination drug delivery of two leading antiretroviral drugs; darunavir (DRV) and its pharmacokinetic enhancer ritonavir (RTV).The LPHNs were designed with a poly(D, L-lactide-co-glycolide) (PLGA) core, and soybean lecithin (SBL) and Brij 78 as the stabilizers. The LPHNs were prepared by modified nanoprecipitation and the effect of synthetic conditions on the particle properties was studied, which included the Z-average diameter and polydispersity index of LPHNs in water and phosphate buffered saline, and the morphology of the particles. This investigation aimed to prepare a formulation that could be stored in its dry and redispersible form, therefore avoiding the challenges associated with storage of dispersions. The optimum ratio of stabilizer to polymer core was established at 20 % w/w, and Brij 78 was found to be crucial in providing colloidal stability in physiological solutions; the minimum amount of Brij 78 required to provide stability in phosphate buffered saline was 70 % w/w of the total stabilizer mass. Viable formulations of LPHNs containing DRV and RTV in the clinically used 8:1 ratio were prepared containing 20 % w/w DRV with respect to the PLGA mass. The use of cryoprotectant, polyethylene glycol, combined with freeze-drying yielded LPHNs with a Z-average diameter of 150 nm when the particles were re-dispersed in water. The oral absorption behavior was assessed using an in vitro triple culture model. Whilst the use of cryoprotectant and freeze-drying led to no improvement of the transcellular permeability compared to the unformulated drugs. The non-freeze-dried samples with the highest soybean lecithin led to increased transcellular permeability, revealing the potential of LPHNs for enhancing HIV treatment.