| خلاصه مقاله | Background: Ferrous sulfate is used as a medicine to treat anemia, which includes the medicinal forms of tablets, drops, and syrup in the pharmaceutical market of Iran. The soluble pharmaceutical forms of this drug mainly have the problem of instability. As a result of oxidation, Fe2+ ions become Fe3+ ions, which have no therapeutic effects. This study aimed to investigate the physicochemical stability of ferrous sulfate syrup in the presence of various formulation factors.
Method: To solve the problems of ferrous sulfate solution formulation, antioxidants such as citric acid, ascorbic acid, and sodium formaldehyde sulfoxylate were used and the pH of these formulations was stabilized with buffer water at 2.2, 3.8, and 5.8. The prepared samples were divided into two packages without oxygen (using nitrogen gas) and normal (with oxygen). On days 0, 14, 28, and 56, they were measured by reductometric titration method with 0.1 N ceric sulfate.
Results: The results showed that the formulations containing citric acid were more stable. Also, if the pH was set at 2.2, the stability of the formulation increased. The usage of ascorbic acid as an antioxidant in ferrous sulfate syrup did not show good results. Sodium formaldehyde sulfoxylate was associated with an initial decrease in the amount of Fe2+, but during the storage period, it was able to keep the amount of Fe2+ constant, especially at pH=2.2.
Conclusion: In general, it can be concluded that using citric acid as an antioxidant and adjusting the pH at 2.2 can improve the stability of ferrous sulfate syrup. |