Osmolality of Commercially Available Oral Rehydration Solutions: Impact of Brand, Storage Time, and Temperature

Abstract

Oral rehydration solutions (ORS) are specifically formulated with an osmolality to optimize fluid absorption. However, it is unclear how many ORS products comply with current World Health Organization (WHO) osmolality guidelines and the osmotic shelf-life stability is not known. Therefore, the purpose of this investigation was to examine the within and between ORS product osmolality variation in both pre-mixed and reconstituted powders. Additionally, the osmotic stability was examined over time. The osmolality of five different pre-mixed solutions and six powdered ORS products were measured. Pre-mixed solutions were stored at room temperatures and elevated temperatures (31 °C) for two months to examine osmotic shelf stability. Results demonstrated that only one pre-mixed ORS product was in compliance with the current guidelines both before and after the prolonged storage. Five of the six powdered ORS products were in compliance with minimal inter-packet variation observed within the given formulations. This investigation demonstrates that many commercially available pre-mixed ORS products do not currently adhere to the WHO recommended osmolality guidelines. Additionally, due to the presence of particular sugars and possibly other ingredients, the shelf-life stability of osmolality for certain ORS products may be questioned. These findings should be carefully considered in the design of future ORS products.

Are oral rehydration solutions optimized for treating diarrhea?

“…In fact, when large losses of water and salt are induced by diuretic to mimic deficits incurred with diarrhea, complete volume replacement with sports drink results in inefficient rehydration and may increase the risk for developing hyponatremia (Gennari and Weise, 2008; Cheuvront et al, 2018). The measured osmolality of liquid sports drinks is hypertonic and the glucose to sodium ratio is 10 times higher than what is recommended for an ORS (Duggan et al, 2004; Sollanek et al, 2019) (Table 1).…”

“… a Osmolality measured using freezing point depression osmometry (Sollanek et al, 2019). b Gatorade contains glucose and sucrose; glucose estimated to be 67% of total carbohydrate, (Gisolfi et al, 1995) i.e.…”