Fabrication of Mold for Creating Multi-Layer Drug Delivery Soft Contact Lens

Due to low absorption of eye-drops and poor patient compliance, developing novel approaches for sustained drug delivery to the eye is vital, especially in glaucoma and ocular surface disorders. Design and fabrication of a multi-layer contact lens is a novel approach to overcome these challenges. In this project, we propose a simple and reproducible protocol for fabricating a multi-layer contact lens. In this method, a three-layer contact lens consisting of two protective layers that encapsulates an inner drug-containing layer is created. The resulting contact lens is no more than one millimeter in thickness for maximum comfort to the user. In order to form this multi-layered lens, a casting method is used. Our approach is to use a 4-piece device that includes a machined polypropylene mold that contains wells of different diameters that will hold the contact lens material. The different well diameters correspond to the eye diameters of mice, rats, rabbits, and humans so that these lenses may be tested on animals and eventually humans. The device also consists of three chrome spheres of various diameters to create sequential layers of varying dimensions. The spheres are utilized to press down the contact lens material in order to form the concave shape of the contact lens. All the sizes including diameter and depth of wells, diameter of spheres and volume of loaded solutions for each layer were calculated mathematically before producing the device. Each layer is then cured under UV light for a total of ten minutes to create a soft contact lens. The resulting lens is three-layered and is capable of supporting drug delivery. With this proof of concept to fabricate multi-layer contact lenses, there is a large potential for fabricating contact lenses with capability of sustained delivery of chemical drugs and biologic therapeutics in ocular disorders.