Abstract: There is provided a solid pharmaceutical composition having active ingredients that include at least one non-enteric coated proton pump inhibitor and at least one buffering agent. The proton pump inhibitor, for example, omeprazole, lansoprazole, rabeprazole, esomeprazole, pantoprazole, pariprazole, and leminoprazole, or an enantiomer, isomer, derivative, free base, or salt thereof, is present in an amount of approximately 5 mg to approximately 300 mg; and the buffering agent is present in an amount of approximately 0.1 mEq to approximately 2.5 mEq per mg of proton pump inhibitor. The dosage form can be non-enteric coated and can be in the form of a suspension tablet, a chewable tablet, an effervescent powder, or an effervescent tablet. Also provided is a method for treating an acid-related gastrointestinal disorder in a subject in need thereof by administering to the subject a solid pharmaceutical composition of the present invention.