[Study of degradation factors of rosuvastatin calcium in order to enhance its stability]

ABSTRACT

The aim of the study is to find the best stability conditions for Rosuvastatin calcium. The study also aimed to ensure that Rosuvastatin analytical method is capable of separating it from its degradation products during stability tests. The stability of Rosuvastatin solution was studied when exposed to accelerated conditions in order to obtain its degradation products, these conditions included the addition of concentrated HCI, sodium hydroxide and hydrogen peroxide associated with high temperature as high as 90°C. The effect of light on stability of Rosuvastatin was also studied by exposing Rosuvastatin solutions to light for 24 hours without additive. The study was also carried on three series were conducted in the dark The first series was carried out without any additive under temps 30, 40, 60 and 90°C and stored for 24 hours. The second series was conducted in the dark under the same temps with sodium hydroxide as an additive. The third one was incubated under the same conditions, with calcium ascorbate as an additives. The studied solutions were analyzed using HPLC. Equal quantities of 20 micro L of each solution were injected into HPLC. Rosuvastatin and its degradation products were analyzed on a C18 [250 mm x 4.6 mm] column octadecyl, using a mobile phase composed of acetonytril 25 parts, methanol 34 parts, water 4 parts, and one part of 3 ethylamine. The pH was adjusted with acetic acid to 4.5. The samples were monitored using UV detector at 240 nm with a Flow Rate of 1 ml/ min. The method showed good resolution for Rosuvastatin peak from the peaks of its degradation products. The results indicated that the proposed method is stability-indicating and could be used in stability tests. It was concluded that the most stable solutions included calcium ascorbate and sodium hydroxide. Light caused higher deterioration of Rosuvastatin; than high temperatures which showed less deterioration of Rosuvastatin solutions