Raft-forming antacids are a class of medicines that block reflux by forming a physical barrier in your stomach. For people with LPR, these are often more effective than other types of antacids. This is because while other antacids may lower the acidity of your stomach contents, they do not prevent those contents from being carried up to your airways, which can be hurt even by less-acidic reflux exposure.
How they work: Raft-forming antacids are designed to create a foam barrier in your stomach. They contain a gel-forming material (typically sodium alginate) and a bubble-forming material (such as sodium bicarbonate). First, the bicarbonate reacts with the acid in your stomach to both lower the acidity of your stomach contents and to release gases. This first step is similar to how most fast-acting antacids work -- you chew up some Tums, they reduce acidity in your stomach, and you burp out the gases. With raft-forming antacids, however, the gases get caught in the gel, and form a foam. This foam floats to the top of your stomach and expands, forming a floating seal (or raft) that prevents stuff below it from getting pushed up into the esophagus.
Why they're better for LPR: With LPR, it's helpful to reduce incidents of reflux -- not just reduce their acidity. Unlike the esophagus, which can handle quite a bit of exposure to food coming in and some reflux coming back, your airways can be sensitive to reflux even when it's not very acidic. Even water can be harmful if it's getting into your lungs.
There are a variety of raft-forming antacids available around the world. These are typically not regulated as drugs and are available without a prescription.
Reflux Gourmet (US)
Gaviscon Advance (UK)
Gaviscon Max Relief (Canada)
Esophageal Guardian (US)
Custom compounding