Designing a novel antacid for sensitive populations

Heartburn is one of the most common medical complaints that can affect every age group of patients all over the world. It is characterized by some kind of pain sensation from around the sternal manubrium to the neck base.¹ As a symptom of esophageal irritation or injury, heartburn is a strong indicator of gastroesophageal reflux disease (GERD). Prevalence of these debilitating symptoms is up to 20% in western populations with at least weekly frequency.² Rate of occasional incidents has been reported even higher, up to 60%.³

The huge population of such patients requires development and mass production of alleviating medications. Currently there are lots of approved drugs for treatment of heartburn and GERD but these are accompanied by high cost and numerous adverse effects. After lifestyle interventions, current guidelines recommend using simple antacids especially for patients with milder and less frequent symptoms.⁴ Maybe the antacids are cost-effective drugs in this field but they have two major drawbacks: limited efficacy and risk for ion accumulative toxicity. Considering the fact that heartburn and acid reflux can be more prevalent in some sensitive and high-risk populations such as pregnant women, patients with kidney or liver failure, neonates and the elderly, designing a safe but strong medication would be highly valuable.

Development of raft-forming antacids has been a revolution in the manufacture of these drugs with the advantages of higher efficacy and increased duration of action but still the problem of toxicity in patients with metabolic and excretory insufficiencies exists. In addition, these innovations have caused some extra complications like occurrence of constipation and flatulence.

In order to optimize an antacid formulation for the above-mentioned sensitive populations we reviewed the scientific literature and common brands to propose a general description for a hypothetically ideal, unique and multi-purpose combination.

Some well-known antacid brands with raft-forming properties have shown adequate efficacy with proven safety in pregnant patients.^5,6 These products generally contain an alginate ingredient, sodium or potassium bicarbonate and a metallic salt such as magnesium, aluminum or calcium compounds. To prevent cation toxicity or sever alkalosis, especially in patients with kidney disease, we suggest taking out the bicarbonate moiety and choosing calcium carbonate among the acid-neutralizing metallic salts. For alleviation of flatulence, aniseed or peppermint extracts can be useful. Limited amounts of these extracts are commonly used and are well tolerated in trials and market as ingredients in products for pregnant populations.⁷ At the end, constipation which is highly prevalent in our target population of patients and could be worsened with a calcium antacid, should be addressed. A candidate for this purpose would be manna of cotoneaster (Iranian traditional medicine) with a high mannitol content that acts as an osmotic laxative. This compound has an extensive history of well tolerated application in neonates and has domestic evidence for tolerability during pregnancy.^8,9 In addition, products of plum or fig will be worthwhile for future evaluations in this indication.

Despite the stated facts, it should be kept in mind that the absence of safety concerns for the ingredients does not necessarily prove that the combination is also well tolerated and further research and exploration about the various combinations will be required. Also, definite dosing stratifications are necessary before making any recommendation especially for less standardized herbal components.

As a conclusion, we can recommend expert manufacturers in gastrointestinal fields to consider a prototype antacid formulation containing sodium alginate, calcium carbonate, peppermint extract and aqueous cotoneaster extract.