Cyclosporin Impurity 4

BACKGROUND: To develop and evaluate the feasibility of emerging interventions, animal models with accurate anatomical environment are required.

Cyclosporine A (CsA) has long been the mainstay treatment for dry eye syndrome (DES), one of the most common disorders of the eye. However, the poor water solubility of CsA renders it difficult to formulate it into topical ocular dosage forms. Restasis® is currently the only US Food and Drug Administration (FDA)-approved CsA formulation, while Ikervis® has recently been launched in Europe, with both commonly associated with severe ocular discomfort. Therefore, several CsA formulations have been investigated with the aim to improve bioavailability while reducing adverse effects associated with the marketed formulations. In this review, we summarize recent advances in ocular CsA delivery that provide safer and more effective alternatives for the management of DES and other ocular inflammatory conditions.

A 6-year-old, intact, male English cocker spaniel was referred for treatment of chronic conjunctivitis and unilateral keratitis. The dog was diagnosed with bilateral immune-mediated keratoconjunctivitis sicca, treated with topical cyclosporine 0·2% ointment and sodium hyaluronate eye drops and improved considerably. After 2 months, pulmonic stenosis was diagnosed, and the dog commenced treatment with oral atenolol; the ophthalmological disease worsened dramatically within a few days. The ophthalmic signs rapidly improved after discontinuation of atenolol, and there was bilateral complete remission after 3 weeks. No oral β-blocker therapy was reintroduced, and thereafter, keratoconjunctivitis sicca was well-controlled with topical therapy.