[The in vitro effect of the addition of ion exchange resins on the bioavailability of electrolytes in artificial enteral feeding formulas].
OBJECTIVE
To determine in vitro free ion concentration in three standard artificial enteral feeding formulas following the addition of ion exchange resins.


METHODS
Three standard types of AEF were chosen: Osmolite HN, Nutrison Standard and Isosource Standard. The ion exchange resins used were: Sodium Polystyrene Sulfonate and Calcium Polystyrene Sulfonate. 100 ml of AEF were mixed in a beaker with 1.5 g or 3 g of ion exchange resins for 48 hours at 37 masculineC. Subsequently, the samples were precipitated and the supernatant obtained was used for determining the concentrations of calcium, magnesium, sodium and potassium ions.


RESULTS
The addition of Sodium Polystyrene Sulfonate to different types of enteral feeding formulas reduced the concentrations of potassium, calcium and magnesium ions by 70%. 78.2%, and 77.6% in the case of Osmolite HN; by 72.3%, 69.2% and 63.5% in the case of Nutrison Standard, and by 78.3%, 80.5% and 74.5% in the case of Isosource Standard. In contrast, the addition of Calcium Polystyrene Sulfonate reduced the concentration of potassium and magnesium by 50.5% and 55.5% in the case of Osmolite HN; by 49.8% and 43% in the case of Nutrison Standard and by 42.6% and 37.7% in the case of Isosource Standard.


CONCLUSIONS
The addition of ion exchange resins to different types of enteral feeding formulas, allows the in vitro free ion content of these to be reduced.
Martí Bonmati
E
E
Servicio de Farmacia Hospitalaria, Consorcio Hospital General Universitario de Valencia, Valencia, España.
Tomas Bondia
F
F
Milara
J
J
Cortijo
J
J
D001682:Biological Availability; D002118:Calcium / Q000493:pharmacokinetics*; D004750:Enteral Nutrition; D005526:Food, Formulated; D007475:Ion Exchange Resins / Q000494:pharmacology*; D008274:Magnesium / Q000493:pharmacokinetics*; D011188:Potassium / Q000493:pharmacokinetics*; D012964:Sodium / Q000493:pharmacokinetics*
D007475:Ion Exchange Resins; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium