2.5 Analyisis of monacolin K content in encapsulated product
1.5 mg of mevinolin or monacolin K standard (Sigma-Aldrich) was dissolved in 0.5 mL of methanol. 2.0 g of encapsulated product was extracted by 20 mL of ethyl acetate pH 3. Extraction was carried out by a shaker incubator at 130 rpm for two hours. The ethyl acetate solution was filtered and the filtrate was placed in a separating funnel. The solution was neutralized by 2 mL of Na2CO3 5% and the ethyl acetate fraction was separated. The ethyl acetate extract was then evaporated by using a rotary vacuum evaporator. The dried extract samples were weighed and dissolved in 5 mL of methanol. Monacolin K analysis was carried out by HPLC method based on Chun-Lin Lee et al.6 with modification. This method involved a Water system C18 column and the sample was eluted with acetonitrile/water (pH is adjusted to 2.5 with H3PO4) at the ratio 55:45, by volume. Analysis was carried out at 26oC for 20 minutes, flow rates were 2 ml/min and detection with a UV detector at 238 nm.