Improving sustained drug delivery from ophthalmic lens materials through the control of temperature and time of loading

Advances in chemistry and composition of soft materials for drug releasing contact lenses

“…4. 49 Silicone based hydrogel contact lenses have been fabricated and have been found to be feasible for ocular drug delivery. 45 These so material contact lenses have higher ability of oxygen transmission on the corneal surface as compared to conventional hydrogel-based contact lens.…”

Therapeutic Ophthalmic Lenses: A Review

“…The simplest method for obtaining therapeutic lenses is soaking into a drug solution [24,[30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]. The amount of drug loaded and released depends on the material and the structure of the lens (e.g., porosity, swelling capacity), on the drug characteristics (e.g., molecular structure, molecular weight, charge), and on eventual interactions that may be established between the drugs and the lens material [22].…”

“…The amount of drug loaded and released depends on the material and the structure of the lens (e.g., porosity, swelling capacity), on the drug characteristics (e.g., molecular structure, molecular weight, charge), and on eventual interactions that may be established between the drugs and the lens material [22]. Besides, the soaking parameters also affects drug loading, i.e., the concentration of the solution [46], loading time [40], and environmental factors, such as temperature and pH [47]. The main issue of the soaking method still is the limited control over the drug release profile, which is usually characterized by a high initial release rate and a short delivery time after lens placement onto the eye [47,48].…”

“…However, the drug could only be detected up to a few hours after implant placement. More recently, Topete et al [40] reached a minimum of eight-day release period of moxifloxacin, diclofenac, or ketorolac from commercially available hydrophilic IOL material through the optimization of the temperature and time of soaking. In particular, loading at 60 • C for two weeks allowed for maximizing drug loading and sustaining moxifloxacin or diclofenac release over time.…”

Supercritical loading of gatifloxacin into hydrophobic foldable intraocular lenses – Process control and optimization by following in situ CO2 sorption and polymer swelling

“…The practice of loading drugs into modern ocular supports has expanded in the last decades in the treatment of various eye diseases such as as glaucoma, posterior capsule opacification (PCO) or endophtalmitis. Several methodologies have been applied such as soaking in liquids (Matsushima et al, 2005;Li and Chauhan, 2006;Kugelberg et al, 2010;Eibl et al, 2013;Wertheimer C et al, 2015;Phan et al, 2016;Topete et al, 2018), molecular imprinting (Hiratani et al, 2005;Maulvi et al, 2019), surface modification (Wang et al, 2015), electrospinning (Mehta et al, 2017), incorporating drugs into colloidal structures, dispersing nanoparticles or microparticles in the polymeric network of lenses Chauhan, 2004, 2005;Kapoor et al, 2009;Jung et al, 2013), grafting or inbuilding (co-polymerization) cyclodextrins into lenses to host drugs by forming dynamic inclusion complexes (Rodriguez-Tenreiro et al, 2006;Ribeiro et al, 2012), formulating liposomes (Danion et al, 2007a(Danion et al, , 2007b(Danion et al, , 2007cJain and Shastri, 2011) or loading contact lenses with microemulsions (Li et al, 2007), etc.…”