Stability of cyclosporine 1% in artificial tears

We wished to determine the stability of frozen, refrigerated, and room temperature topical cyclosporine 1% in artificial tears (Tears Plus). Cyclosporine 1% eye drops were made in artificial tears prior to the manufacturers recommendations of using a lipid soluble vehicle, such as olive oil. Patients preferred the artificial tears preparation over the oil based cyclosporine product. Because of the good clinical response and the reluctance of patients to change to the oil vehicle product, we determined the stability of cyclosporine 1% in artificial tears. Cyclosporine 1% was prepared in artificial tears (polyvinyl alcohol 1.4% and povidone 0.6%) by adding 1 ml of the injectable (50 mg/ml) cyclosporine into 4 ml of the artificial tears solution. Each bottle was frozen at -20 degrees C for one month and then the cyclosporine concentration was determined after thawing and refrigeration or storage at room temperature. Refrigerated stability was determined after thawing for up to 28 days and room temperature stability was determined for up to 1 week after thawing. Cyclosporine concentration was determined by HPLC analysis. None of the samples exhibited any significant loss of cyclosporine at any time period. Frozen cyclosporine appears stable when frozen in a 1% solution for one month. Cyclosporine 1% in artificial tears is stable for up to 28 days in the refrigerator or at least 7 days at room temperature. Because of the ease of preparation, the proven clinical effectiveness of the product and better patient acceptance, we continue to make this product.