Stability of Oral Vitamin K Solutions Stored in Amber Plastic Syringes

• Main Authors: Lawson, Sarah, Brown, Stacy
• Format: Others
• Published: Digital Commons @ East Tennessee State University 2018
• Subjects: Vitamin K; Syringes; Stability; Pharmacy and Pharmaceutical Sciences
• Online Access: https://dc.etsu.edu/asrf/2018/schedule/102

Oral vitamin K is administered to patients who have very high INR lab values and are on warfarin therapy. Due to the inability of some patients to swallow tablets, and the commercial formulation of vitamin K being available only as a tablet or an injectable emulsion, it may be necessary to compound an oral liquid formulation. When compounding batches of oral solutions, it is sometimes convenient to measure the product in unit doses. In this project, we compared liquid vitamin K in sterile water (1mg/mL) verses liquid vitamin K in Ora-Sweet (1mg/mL) stored in amber plastic syringes. Vitamin K is light sensitive and is best stored in amber containers. Vitamin K is also lipophilic and may adsorb to the plastic syringes. In this study, we investigated the feasibility of bulk compounding oral vitamin K solutions, and aliquoting them for storage in amber plastic syringes. The Vitamin K in sterile water syringes were made by mixing 45 mL of sterile water and 5 ampules, each containing 10mg/mL of vitamin K emulsion, together in an amber glass bottle for a final concentration of 1mg/mL. Thirty 1mL plastic amber syringes were filled with the mixture, capped, and placed in the refrigerator. The same process was repeated using Ora-Sweet instead of sterile water to fill thirty more plastic amber syringes. Three syringes of vitamin K in sterile water mixture, three syringes of vitamin K in Ora-Sweet mixture, and one Vitamin K reference standard were all analyzed using HPLC-UV on the day of compounding, and at day 1, 2, 4, 7, 14, 21, 30, 60, and 90. If stability is defined as 90-110% active ingredient, then Vitamin K in sterile water is stable to fourteen days, 95.3±3.5% recovery, but some samples fell below 90% recovery after 14 days. By day ninety, the recovery in SWFI syringes was 84.2±8.9%. For vitamin K in Ora-Sweet, the within-day variability was very high due to limitations in drug dissolution; as such the average concentration was not consistently above 90%. On the day of compounding, the percent recovery in the Ora-Sweet syringes was 92.7±9.9%, despite 1 hour of stirring. In conclusion, the Vitamin K in sterile water mixture can be stored in refrigerated, amber oral plastic syringes for 14 days, but plastic amber syringes were not appropriate for storage of the Vitamin K in Ora-Sweet mixture.