Osmolality, pH, and Compatibility of Selected Oral Liquid Medications With an Enteral Nutrition Product

Abstract

When selecting medication for feeding tube administration, the liquid formulation is selected, so as to avoid obstructions that may occur from incompletely crushing a solid dosage form. Liquid medications can present issues of intolerance and compatibility when administered via a feeding tube. A predictor of intolerance is the liquid's osmolarity, and a predicator of compatibility is the liquid's pH value. This study examines 62 liquid formulations for their osmolality, pH, and physical compatibility with enteral nutrition (EN) formulas. These medications were selected as being the most commonly dispensed liquid medications from our outpatient pharmacy department. This study measures osmolality using freezing point depression. Depending on the dose, the osmotic load of a liquid medication may cause cramping and diarrhea. The pH value is predictive of potential interactions with the EN formula. Many drugs are weak bases and require acidic vehicles for optimal stability. The acidic liquids are especially reactive with enteral formulas that contain intact proteins. The result of this interaction can result in an occlusion of the feeding tube as the proteins form a gel-like clog. This study combined the liquid medication directly with the EN formula to determine the potential for feeding tube occlusion. Some drugs formed a solid mass in the test tube immediately, whereas others only presented granules, which may later contribute to obstructing the feeding tube. The prescriber should be aware of the potential impact of their choice in formulation, both in terms of the gastrointestinal tolerance and potential for interaction with coadministered nutrition.

Pre-absorption physicochemical compatibility assessment of 8-drug metabolic cocktail

“…The midazolam solubility profile, including its significant drop from 2.4 mg/ml at pH 4.2 to 0.4 mg/ml at pH 5.0, has been previously reported [33]. At physiologic conditions (pH [5][6][7][8], any openring form present reverts to the physiologically active, lipophilic, closed-ring form of midazolam, and is absorbed into the systemic circulation as such [39]. With the rationale for midazolam acidic syrup formulation understood, it was concluded that there was no specific concern for including midazolam in the 8-drug cocktail based on 2 considerations: 1) The inclusion of midazolam acidified the drug cocktail mixture, however, the other drugs were all designed to first encounter an acidic environment in a human stomach anyway and therefore the impact should be minimal.…”

“…For example, the stability of commonly used drugs with enteral nutrient formulas (ENFs) was studied to ensure the suitability of using these drugs for patients on ENFs. The reported methods for determining the physical compatibility of drugs with ENFs include the observation/determination of viscosity change, particle growth, granulation, precipitation, phase separation, pH and osmolarity change, and concentration analysis [4][5][6][7][8][9]. It has reported that some drugs formed a solid mass immediately in the test tube with ENF [5], this reaction could have caused the obstruction of a feeding tube.…”

Osmolality and pH in handmade enteral diets used in domiciliary enteral nutritional therapy

“…When pH is lower than 3.5 it may interfere in gastric motility and contribute towards a slower gastric emptying (Araújo & Menezes, 2006;Klang et al, 2013;Blumenstein et al, 2014). …”

“…Its analysis is important to assess the physiological acceptance capability of the diet and to avoid complications (Barrett et al, 2009 by providing a solubility environment to the nutrients. It is also crucial for the microbiological control of the solution (Klang et al, 2013;Pinto et al, 2015). Non-industrialized enteral diets with a pH rate favorable to microbiological growth may be an infection vector for patients undergoing enteral nutritional therapy if preventive hygiene measures are not applied during food handling (Blumenstein et al, 2014).…”

A Novel Functional Fruit/Vegetable Beverage for the Elderly: Development and Evaluation of Different Preservation Processes on Functional and Enriched Components and Microorganisms

“…Osmolality is a crucial determinant of the physiological acceptance of the beverage. The desired osmolality should be < 700 mOsm (Klang, McLymont, & Ng, 2013). An appropriate osmolar load is necessary for the beverage be tolerated by a eutrophic elderly consumer, ensuring the successful assimilation of the formulation components.…”