Sustained latanoprost release from PEGylated solid lipid nanoparticle-laden soft contact lens to treat glaucoma

Abstract

Contact lens have been proposed as a mean of ocular drug delivery, but the conventional soaking method to load hydrophobic drugs, such as latanoprost shows low drug loading and high burst release with alteration in the critical lens properties. In this paper, a novel latanoprost-loaded PEGylated solid lipid nanoparticles (LP-pSLNs) were developed to increase the latanoprost loading capacity of contact lenses (LP-pSLN-L), while also sustaining ocular drug delivery. The pSLNs were spherical in shape with an average size of 105‒132 nm (nanometer) and a zeta potential ranging from ‒29.1 to ‒26.7 mV (millivolt). The LP-pSLNs led to improved swelling, transmittance, and protein adherence of the lens compared to the non-pegylated SLNs congeners (LP-SLN-L) and conventional soaked lens (LP-SM-L). The LP-SM-L lens showed low drug loading, high burst release, and a short release duration of 24 h. The LP-SLN-L and LP-pSLN-L lenses showed high drug uptake and sustained drug release up to 120 h and 96 h, respectively. The pegylation reduced the size of nanoparticles and improved the drug loading capacity, while the release rate was high in the initial hours. The LP-pSLN-L lens was found to be safe based in histopathological studies. In animal studies, the LP-pSLN-10-L batch showed high drug concentration at all-time points up to 96 h compared to the LP-SM-L and eye drop solution. In conclusion, pSLNs improved the latanoprost loading in the contact lens and showed sustained drug release, and thus can be used as a substitute to eye drop therapy.