In vitro and in vivo performance of epinastine hydrochloride-releasing contact lenses

Abstract

A number of drug-releasing contact lenses are currently being studied to address issues inherent in eye drops as a drug delivery method. In this study, we developed epinastine hydrochloride-releasing daily soft contact lenses for treatment of allergic conjunctivitis and examined their in vitro and in vivo performance. Preformed soft contact lenses with/without ionic functional groups were soaked in a solution of epinastine hydrochloride in phosphate-buffered saline to prepare epinastine hydrochloride-releasing soft contact lenses. Among these contact lenses with different ionicities, anionic lenses demonstrated the maximum, relatively linear epinastine hydrochloride release, in vitro. The amount of epinastine hydrochloride release was directly proportional to the concentration of the epinastine hydrochloride solution used to prepare the contact lens. The epinastine hydrochloride-releasing anionic soft contact lens also demonstrated prolonged drug release and significantly greater efficacy compared with epinastine hydrochloride eye drops 12 h after treatment, in vivo. Further studies are required to determine the appropriate amount of epinastine hydrochloride to be contained in the anionic soft contact lenses.

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

“…Minami et al studied the loading and release of the selective histamine H1 receptor antagonist, epinastine hydrochloride (EH) from so material contact lens having anionic, cationic and non-ionic co-monomers incorporated during the fabrication of the contact lens. 53 The ionic nature of the comonomer used, inuenced the and drug release kinetics. HPMA (N-(2hydroxypropyl)methacrylamide), a non-ionic monomer was used of the fabrication of all the contact lenses.…”

Soft Contact Lenses as Drug Delivery Systems: A Review

“…Its limitation, however, is that the release of the drug occurs very quickly since the charging of the drug is dependent on the ionity and water content of contact lens materials [ 61 , 62 ]. This method, developed in 1965 [ 49 ], has been used in many studies to incorporate ophthalmic drugs such as antibiotics [ 63 ], antihistamines [ 64 ], non-steroidal anti-inflammatory drugs, corticosteroids [ 65 ], tear stimulants [ 61 , 62 ], and anti-glaucoma medications [ 66 ]. Even though most of the studies in the literature have been performed in vitro, some authors have assessed both the retention time and efficacy of various drugs in vivo, showing better results for soaked contact lenses than topical eye instillation.…”

The spectrum of allergic ocular diseases

“…118 Furthermore, epinastine hydrochloride-releasing soft contact lenses has been found to have prolonged drug release and greater efficacy compared with the use of epinastine hydrochloride eye drops 12 hours after treatment. 119 Omalizumab, a recombinant anti-IgE monoclonal antibody, has been found to have decreased burning, itching, and need for topical antihistamines, topical and oral steroids, improvement in lid eczema, and improved quality of life in case reports and series of patients with severe VKC and AKC, despite failure of immunosuppressive therapies. [120][121][122][123][124][125][126] Patients may have relapse of symptoms on discontinuation of omalizumab, but symptoms remit upon drug reinitiation.…”