Shelf life after opening of prescription medicines and supplements with vitamin D3 for paediatric use.

OBJECTIVES: The aim of this study was to evaluate the effect of storage conditions on the shelf life of liquid pharmaceuticals with vitamin D3 in order to determine appropriate storage conditions and shelf life after the product has been opened. Manufacturers rarely specify the shelf life after products have been opened, which leads to a controversial debate among medical professionals regarding the safety of products after opening and optimal storage conditions and considerably different recommendations to the public. METHODS: Effect of storage conditions on the shelf life was evaluated by comparing the isothermal stability of vitamin D3 in three prescription and three non-prescription medicines at different temperatures (4°C, 25°C and 40°C) using stability-indicating high performance liquid chromatography assay. RESULTS: Most of the examined preparations had a higher vitamin D3 content than the label claim when the products were first opened, presumably to compensate for loss during production and storage. An association was observed between the initial vitamin D3 content and its stability in the preparations. The vitamin D3 overage in liquid prescription medicines guaranteed its content >90% of the amount claimed on the label for at least 1 year when stored at 25°C and for 4 months at 40°C. All tested preparations are consumed when used as recommended over this period. Since some manufacturers recommend storage below room temperature, redefining the storage conditions is of practical significance. CONCLUSIONS: The shelf life after opening examined prescription medicines containing vitamin D3 as their main active ingredient is at least 1 year at room temperature.

Stability-Indicating HPLC-UV Method for Vitamin D3 Determination in Solutions, Nutritional Supplements and Pharmaceuticals.

A simple and fast high-performance liquid chromatography method with UV detection for determination of vitamin D3 in stability studies as well as in solutions, nutritional supplements and pharmaceuticals was developed. Successful separation of vitamin D3 from its degradation products was achieved on a Gemini C18 100 × 3.0 mm column using a mixture of acetonitrile and water (99:1, v/v) as а mobile phase. The method was successfully validated according to the ICH guidelines. The described reversed-phase HPLC method is favorable compared with other published HPLC-UV methods because of its stability-indicating nature, short run time (3.3 min) and wide analytical range with outstanding linearity, accuracy and precision. The method was further applied for quantification of vitamin D3 in selected liquid and solid nutritional supplements and prescription medicines, confirming its suitability for routine analysis. Degradation products, formed under stress conditions (hydrolysis, oxidation, photolysis and thermal degradation), were additionally elucidated by suitable equipment (LC-DAD-MS) to confirm the stability-indicating nature of the developed method.