In this comprehensive review the numerous disadvantages of contact lenses as medicated lenses and the strategies to overcome the same numerous approaches have been explored. Researches worldwide have come a long way from cyclodextrin-based and vitamin E-based modified contact lenses to bioinspired approaches to enhance the effectiveness of the drug-eluting contact lenses. The bioinspired approach exploits bioinspired polymeric systems to enhance biocompatibility, specific molecule recognition technique by molecular imprinting, or stimuli-responsive system to improve the biocompatibility, drug loading, and drug delivery efficacy of the drug-eluting contact lenses. Moreover, recent innovations in ocular therapeutics such as nanowafers and microneedle contact lenses, and ocular patches have gained tremendous attention in ocular therapeutics. Another potential application of the contact lenses are smart lenses applied in the biosensing and diagnosis of various ocular disorders. The review summarizes and discusses the widespread therapeutic applications of next-generation contact lenses and various fabrication approaches, including its clinical implications, efforts taken by researchers in exploring the novel materials and diverse forms of the lenses, mechanisms of drug release, clinical trials, and their toxicity and safety concerns.
Among others, also the cyclodextrin enabled drug-eluting contact lenses are reviewed. The various strategies using CD are copolymerization of acrylic/vinyl CD derivatives or grafting of CD, or direct cross-linking of CD during the preparation of contact lenses. It was observed that low drug loading associated with soaking and imprinted molecular techniques can be overcome by cross-linking with poly-(CD). With the help of CDs hydrogels with improved diclofenac loading by 1300% and a 15-fold increase in drug affinity were prepared. CDs also hinder protein adsorption.
Pinal Chaudhari, Vivek M. Ghate, Shaila A. Lewis (2021) Next-generation contact lenses: Towards bioresponsive drug delivery and smart technologies in ocular therapeutics. European Journal of Pharmaceutics and Biopharmaceutics 161, 80-99. https://doi.org/10.1016/j.ejpb.2021.02.007.