ABSTRACT
PURPOSE: NHS Blood and Transplant Tissue and Eye Services provide a serum eye drop (SED) service to patients suffering from severe dry eye syndrome. Currently SED are dispensed using an automatic closed filling system (TF) manufactured by Meise Medizintechnik (Germany). An improved version (ATS) has recently been introduced by Meise, based on patient feedback on the TF system. ATS vials are easier to open, with a more secure, tamper evident closure and a better quality nozzle.To evaluate the suitability of ATS vials, a validation protocol, previously developed for TF vials, was repeated. It comprised assessment of their integrity following simulated storage and transport, and the stability and sterility of SED stored in them. METHOD: Firstly, a process simulation assessment was performed using bovine serum. Vials were filled, and frozen to -80oC. They were then removed from frozen storage and checked for damage, before being put into transport containers and shipped on a round-trip journey to simulate delivery to patients. On return the vials were thawed and the integrity of each vial checked visually and by application of a standard force.Subsequently a shelf-life study was carried out using three batches of human SED. The vials were initially frozen to -80oC, then stored for set time points of 1, 3, 6 and 12 months in a standard domestic freezer set at 20oC (to mimic a home freezer). At each time point, 10 vials were thawed and examined for integrity, and the sterility and stability of the contents. Stability was assessed by measuring serum albumin concentrations and sterility by testing for presence of microbial contamination, under aerobic and anaerobic conditions. RESULTS: No vial damage or leakage was found at any time point in the ATS vials. No microbial contamination was detected, and no change in albumin levels was detected in SED throughout the storage period. CONCLUSION: This study has demonstrated that the ATS vials are suitable for provision of SED for clinical use to patients. Feedback is now being gathered from a patient focus group relating to usability of the vials.
