The objective of this study is to investigate the prescription and preparation technol. of Compound Niacin Sustained-release Tablets.With reference to supplementary material in the English instructions abroad, we studied the compound layer sustained-release tablet as same as the foreign formulation.The release rate and content of niacin and lovastatin at different times were determined to judge the sustained-release effect and to observe the slow-release matrix material fillers, filler, adhesives, lubricants, dosage and preparation technol.The release degree and content indexes of three batches of samples with determined prescription and preparation technol. were determinedThe sustained-release tablet core was prepared with niacin as main drug, HPMC as blocker, PVP as binder, stearic acid as lubricant.The coating liquid was prepared with lovastatin as main drug, crosslinked Na-CMC as coating material, PEG-400 as plasticizer, tween-80 as solubilizer, and titanium powder as sunscreen.This technol. is mature and cheap with qualified release degree.