Preliminary in-vitro evaluation of marketed formulations for antacid activity

Background: Hydrochloric acid (pH 1.5-3.5) being the major component of gastric acid is produced by parietal cells of stomach. Its secretion is a complex and relatively energetically expensive process. The preservation of acidity of stomach is evidently important because of its implications in peptic and duodenal ulceration.Methods: In the present study, we attempted to compare the activity of 13 (F1-F13) antacid formulations (5-liquid, 4- quick releases and 4- tablets) by using acid-base neutralization studies. Preliminary antacid test (PAT) was performed to define whether the given formulation falls under the category of antacid wherein the pH of the antacid-acid (HCl) solution should be higher than pH of 3.5. The chosen antacids were further subjected to acid neutralizing capacity (ANC) (reaction between the sample of antacid and amount of acid neutralized by the formulation) and acid neutralizing potential (ANP) which explains the time duration during which a given sample of antacid can maintain pH above 3.5).Results: Out of the 13 samples tested, two formulations of pastels (F6, F12) were rejected as per the standard protocol of classifying formulations as antacids after screening for PAT. Sample F5 was found to have the highest ANC. F7 also showed highest ANC among the tablets tested. Also, F13 showed better ANC and ANP as in comparison to other quick releases.Conclusions: Digene products (F5, F7, and F13) showed better antacid properties. This data would provide insights into development of drug, comparison between antacids depending on their chemical formulation and determination of dosage to avoid plausible side effects

Comparison of two marketed effervescent fast relief formulations for antacid activity-an in vitro study

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