Issue link: https://www.e-digitaleditions.com/i/733311
Tablets & Capsules October 2016 17 I quality Effect of sampling methods on vitamin D blending uniformity Wenming Zeng, Dan Wang, and Doug Roper Pharmavite The study described here investigated the effect of sampling methods on vitamin D blending uniformity in a calcium-magnesium-zinc- vitamin D (CaMgZnD) tablet formula. Analytical testing results indicate that samples taken with a sampling thief had a large relative standard deviation (RSD) of vitamin D content, while samples taken from a discharge stream had a smaller RSD. Content unifor- mity testing results using single-tablet samples agreed with results from samples taken using the discharge method. Poor uniformity data in vitamin D from thief sampling may be caused by an elec- trostatic charge during sampling. n the USA, blending uniformity studies are not required for dietary supplement products but are required for drug products, and the FDA offers a Guidance about blending uniformity studies [1]. However, in other coun- tries, such as China, dietary supplements are treated as drugs. If an American company wants to register a dietary supplement product with China's FDA, the company must provide its blending uniformity data. Some large dietary supplement manufacturers, like Pharmavite, con- duct blending uniformity studies in order to ensure high product quality. It now appears that conducting unifor- mity studies as part of product development is becoming