Metformin or a pharmaceutically acceptable salt thereof for use in providing continuous and non-pulsating plasma levels of an antihyperglycemic drug with a peak plasma level within 8-12 hours after administration when administered with or shortly after the evening meal in a controlled release pharmaceutical tablet exhibiting the following dissolution profile when tested in a USP type 2 apparatus at 75 rpm in 900 ml of simulated intestinal fluid (pH 7.5 phosphate buffer) and at 37 °C: - after 2 hours 0-25% of the drug is released； - after 4 hours 10-45% of the drug is released； - after 8 hours 30-90% of the drug is released； - after 12 hours not less than 50% of the drug is released； - after 16 hours not less than 60% of the drug is released； and - after 20 hours not less than 70% of the drug is released.
