Studies on the Stability of 0.625% Povidone-Iodine for Eye Washing

• Published in: Iryo Yakugaku (Japanese Journal of Pharmaceutical Health Care and Sciences) Vol. 29; no. 1; pp. 62 - 65
• Main Authors: Takekuma, Yoh, Yamashita, Yasunori, Iwai, Miwako, Kishino, Satoshi, Suda, Noriyuki, Shiga, Hiroyasu, Miyazaki, Katsumi
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of Pharmaceutical Health Care and Sciences 2003
• Subjects: disinfectant; povidone-iodine (PVP-I); shelf-life; stability
• ISSN: 1346-342X; 0015-749X; 1882-1499; 1882-1499
• DOI: 10.5649/jjphcs.29.62

A 0.625% povidone-iodine solution (PVP-I) for eye washing, a pharmaceutical product prepared in our hospital, is used to disinfect the conjunctival sac in eye surgery. Since iodine is unstable, its bactericidal activity is reduced when PVP-I is diluted. Therefore, the stability of a 0.625% PVP-I solution under various preservation conditions was studied. Its stability was evaluated by pH variation, visual inspection and the residual rate of available iodine. The 0.625% PVP-I solution was stored for 5 weeks at room temperature (25°C) and at 4°C under diffused light or in a dark place. The amount of available iodine was determined by the oxidationreduction titration method according to the fourteenth revised edition of the Japanese Pharmacopoeia (JPXIV). No apparent changes were found by pH variation or visual inspection after storage for 5 weeks either at 4°C or 25°C. The residual rates of available iodine after 5 weeks of storage were 91 % at 25°C and 98% at 4°C, thus suggesting that a reduction in available iodine is smaller at 4°C than at 25°C. This finding also suggests that a reduction in available iodine is dependent on temperature. The results of this study indicate that a 0.625% PVP-I solution for eye washing remains stable for 5 weeks if stored at a temperature of less than 4°C.