This guidance is developed to provide manufacturers with recommendations for submission of new drug applications (NDAs), investigational new drug applications (INDs), and/or abbreviated new drug applications (ANDAs), as appropriate, for immediate-release (IR) tablets and capsules that contain highly soluble drug substances. The guidance is intended to describe when a standard release test and criteria may be used in lieu of extensive method development and specification-setting exercises. When final, this guidance will supersede the guidance for industry on Dissolution Testing of Immediate Release Solid Oral Dosage Forms (August 1997) for biopharmaceutics classification system (BCS) class 1 and 3 drug substances in immediaterelease drug products that meet the criteria in this guidance. For class 2 and 4 drug substances, applicants should still refer to the August 1997 guidance mentioned above.