Background: Hyper-acidity is excessive formation of acid (pH=1.5-3.5) in the stomach by parietal cells which causes a burning sensation in the chest. The preservation of gastric acid insult is crucial because of the implications of hyperacidity in gastroesophageal reflux disease (GERD), peptic ulcers and duodenal ulcers. Acidity is controlled by use of some over-the-counter (OTC) antacid formulations containing magnesium or aluminum hydroxides.Methods: In the present study, the preliminary antacid test (PAT), the pH acid neutralizing capacity (ANC), acid neutralizing potential (ANP) along with buffering capacity of two well-known quick release formulations (F1 [Digene Ultra Fizz] and F2 [a standard, commercially available product]) were determined. Results: According to US pharmacopeia USP, both the antacid formulations passed the PAT test. PAT results revealed that the pH of the acid-antacid solution was higher in F1 (8.20±0.02) as compared to F2, (6.53±0.01). The ANC results revealed that F1 (46.89±0.6 mEq/dosage) had higher neutralizing capacity as compared to F2(30.12±1.3 mEq/dosage). Higher ANP was observed for F1 (245 mins), and it was 2.7 times that of F2 (90 min). The onset of action for both the antacids was <2 seconds. Additionally, buffering capacity was evidently observed during ANP analysis in the case of F1. Independent T test performed for all the tests revealed that the data obtained was highly significant (p<0.01).Conclusions: F1 showed high antacid and buffering properties when tested in vitro. The present study highlights the need for future research on specific OTC non-prescribed antacid formulations with respect to their price, efficacy and side effects.