The invention relates to methods and composition for improving absorption and dissolution of active ingredients of drugs. The invention provides a method of administration of an active ingredient to a mammal through a transmucosal route that includes delivering the active ingredient to a desired site in a body of the mammal, and, sequentially, at the desired site, promoting dissolution and absorption of the active ingredient. In a preferred embodiment, the pH of the localized environment of the active ingredient is sequentially modified to promote dissolution and absorption.