Disclosed is a method for stabilizing a solid pharmaceutical preparation containing a pharmacological substance and sodium lauryl sulfate, the method comprising incorporating into the preparation at least one member selected from the group consisting of neutral salts, basic salts and basic substances. The preparation containing sodium lauryl sulfate prepared by the method of the invention has superior performance, including high storage stability, suppression of discoloration and deterioration, and prevention of change in its properties, such as the dissolution rate of pharmacological substance from the preparation.
