Particle Size Stability of Intralipid and Mixed Total Parenteral Nutrition Mixtures

Abstract

SUMMARY The determination of the particle size of Intralipid fat emulsions by the nonperturbing method of photon correlation spectroscopy has been extended to include particle size determination using the Coulter counter and optical microscopy. Although little increase in particle size in 3‐litre bags containing total parenteral nutrition mixtures was observed with the methods involving large dilutions, creaming was observed and optical microscopy showed aggregation and some coalescence to have taken place. The problem of re‐dispersion upon dilution of aggregated (but not coalesced) fat emulsions makes direct optical observation essential in assessing the stability and safety of such fat emulsion mixtures. The effect of electrolytes (NaCl and CaCl2) on creaming, particle size and electrophoretic mobility showed both minimum stability and minimum zeta potential at 3 × 10‐3mol dm‐3 CaCl2and at 2. 5 × 10‐1mol dm‐3NaCl. Thus, these maximum levels for electrolytes in total parenteral mixtures are indicated.

PFAT5 and the Evolution of Lipid Admixture Stability

“…The addition of cations to an undiluted sample of fat emulsion 10% will shift the repulsive forces of the charged particles 19 . It was assumed that this phenomenon would also occur in a TNA after the addition of large quantities of electrolytes 20 , 21 . The relative lack of change in zeta potential has been interpreted as confirmation of TNA stability 22 .…”

“…19 It was assumed that this phenomenon would also occur in a TNA after the addition of large quantities of electrolytes. 20,21 The relative lack of change in zeta potential has been interpreted as confirmation of TNA stability. 22 Acidic additives, such as dextrose, will have a disruptive effect on the stability of a TNA by lowering the total pH of the system and the zeta potential.…”

Temperature-dependent optical properties of Intralipid® measured with frequency-domain photon-migration spectroscopy

“…As Intralipid is known to decay over time, 20 a fresh solution was prepared for each set of measurements. Figure 2 shows the absorption coefficient of Intralipid, calculated from the amplitude and phase measurements, over the wavelength range 710 to 850 nm measured at the three different temperatures.…”

An interfacial equilibria model for the electrokinetic properties of a fat emulsion. Part II: Magnesium, zinc and proton interactions with the interface

“…The stability, however, is compromised by formulating 'All in One' regimens (Black and Popovich, 1981;Pamper! and Kleinberger, 1982;Burnham et al, 1983;Allwood, 1984;Whateley et al, 1984;Davis et al, 1985;Davis and Galloway, 1986;Driscoll et al, 1986). Preparations of 'All in One' regimens involve the admixture of emulsions, amino-acids, trace elements and vitamins resulting in a single infusion that satisfies most, or all, of the nutritional requirements of the patient.…”