Plenity (Oral Superabsorbent Hydrogel).

Abstract

Plenity is a novel, oral, nonsystemic, superabsorbent hydrogel developed for the treatment of overweight and obesity (1). This new product, approved by the U.S. Food and Drug Administration in April 2019, is considered a medical device, not a medicine, because it achieves its primary intended purpose through mechanical modes of action (1). This oral superabsorbent hydrogel has a labeled indication for weight management in overweight and obese adults with a BMI of 25–40 kg/m2 when used in conjunction with diet and exercise (2). There are two naturally derived building blocks in this product; modified cellulose is cross-linked with citric acid, which creates a three-dimensional matrix. Each capsule contains thousands of superabsorbent hydrogel particles. When taken orally with a meal, the capsules disintegrate in the stomach, resulting in the release of these particles (2). The individual nonclustering hydrogel particles occupy about one-fourth of a person’s stomach volume when that person is fully hydrated (2). The gel particles mix with ingested foods, creating a larger volume, with higher elasticity and viscosity, in the stomach and small intestine, thus promoting satiety and fullness (2). The gel particles maintain their three-dimensional structure and mechanical properties during transit through the small intestine. Upon arrival in the large intestine, the hydrogel is partially broken down by enzymes and loses its three-dimensional structure along with most of its absorption capacity. The released water is then reabsorbed, and …