Physicochemical assessments of parenteral lipid emulsions: light obscuration versus laser diffraction

Driscoll, David F.; Etzler, Frank M.; Barber, Thomas A.; Nehne, Jörg; Niemann, W.; Bistrian, Bruce R.

doi:10.1016/s0378-5173(01)00626-3

Cited by 75 publications

(48 citation statements)

References 8 publications

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“…However, the inconsistencies may relate more to species differences. Human chylomicrons are reported to have particle diameters of 316 -352 nm (10,21,22); this correlates well with commercial lipid emulsions, which have particle sizes in the 286-to 340-nm range (10,23). In contrast, rat chylomicrons have been found to have mean diameters of 130 -160 nm (24 -26).…”

Section: Discussionmentioning

confidence: 61%

Systemic and Forearm Triglyceride Metabolism

et al. 2004

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Little is known about the fate of the lipolytic products produced by the action of lipoprotein lipase (LPL) on circulating triglyceride-rich lipoproteins in humans. We studied eight lean, healthy male subjects after an overnight fast. Subjects received infusions of lipid emulsions containing triolein labeled with 3 H on both the glycerol backbone and the fatty acid portion of the molecule; 14 C glycerol and 14 C oleate were coinfused to quantify the systemic and forearm release of 3 H glycerol and 3 H oleate resulting from LPL action. There was significant forearm uptake of both whole plasma triglyceride (presumed to represent primarily VLDL; extraction fraction 2.6 ؎ 0.6%, P < 0.005 vs. zero) and radiolabeled triglyceride derived from the lipid emulsion (a surrogate for chylomicrons; extraction fraction 31 ؎ 4%, P < 0.005 vs zero). Systemic clearance and forearm fractional extraction of glycerol was greater than that of oleate (P < 0.001 and P < 0.02, respectively). The systemic and forearm fractional release of LPL-generated glycerol were similar at 51 ؎ 4 and 59 ؎ 1%, respectively (NS). In contrast, the forearm fractional release of LPL-generated oleate was less than systemic fractional release (14 ؎ 2 vs. 36 ؎ 4%, P < 0.0001). These results indicate that there is escape, or spillover, of the lipolytic products of LPL action on triglyceride-rich lipoproteins in humans. They further suggest that LPL-mediated fatty acid uptake is an inefficient process, but may be more efficient in muscle than in adipose tissue. Diabetes 53:521-527, 2004 A lthough it is generally accepted that the action of hormone-sensitive lipase (HSL) in adipocytes is the primary source of plasma free fatty acids (FFAs) in normal postabsorptive individuals (1), the ubiquitous presence of lipoprotein lipase (LPL) (2) represents a potential additional source of plasma FFAs. Available evidence suggests that VLDL triglyceride is not an important source of plasma FFAs. Wolfe et al. (3) administered biosynthetic labeled VLDL to dogs and found that Ͼ95% of VLDL-triglyceride fatty acids were taken up directly into tissues without traversing the plasma FFA pool; in contrast, glycerol produced by the action of LPL on VLDL triglyceride was quantitatively released into the circulation.Chylomicrons, on the other hand, appear to be a significant source of FFAs during meal absorption. However, the magnitude of the chylomicron contribution to total FFA flux is controversial. Olivecrona et al. (4) gave chylomicrons labeled with 14 C glycerol and 3 H palmitate to rats, and found that ϳ90% of the administered 3 H was recovered in adipose tissue, whereas only trace amounts of 14 C could be found in adipose tissue. Recently, studies in which both chylomicrons and lipid emulsions containing labeled oleate were administered to mice found that 80 -90% of the label was recovered in plasma (5). Roust and Jensen (6) gave a meal containing radiolabeled triglyceride to human subjects and found that approximately one-third of dietary fatty acids were released into the sy...

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Section: Discussionmentioning

confidence: 61%

Systemic and Forearm Triglyceride Metabolism

et al. 2004

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“…9 The physical stability of lipid emulsions can be tracked by an array of techniques, including particle size analysis via photon correlation spectroscopy, light obscuration, laser diffraction, or microscopy. [10][11][12][13] While these methods can follow physical changes, zeta potential and pH measurements are able to indicate chemical processes that take place during storage. Dynamic surface tension measurements can provide additional information concerning the physicochemical processes that occur on the surface of the lipid droplets.…”

Section: Introductionmentioning

confidence: 99%

“…[8][9][10][11][12][13][14] Electrolytes play an especially important role in stability, as they are present in all admixtures and have a major effect on the zeta potential of the emulsions. In the case of nonspecific adsorption, they physically adhere to the surface of the lipid droplets and above the critical flocculation concentration (CFC) cause the disappearance of repulsive forces.…”

Section: Introductionmentioning

confidence: 99%

Tracking of the kinetic stability of 2 types of total nutrient admixtures containing different lipid emulsions

et al. 2006

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The physical stability of 2 types of total nutrient admixtures was studied as a function of storage time and temperature. One of them contained only structured triglycerides and the other exclusively long-chain triglycerides as lipid components. To evaluate the possible changes in the kinetic stability of the emulsions and in the surface characteristics of the droplets during storage, particle size analysis, zeta potential, and dynamic surface tension measurements were performed. To follow any chemical decomposition processes that occurred during storage, the pH of the emulsions was also monitored. The mean droplet size of emulsions prepared with lipids containing exclusively long-chain triglycerides showed a remarkable increase after 4 days of storage, in contrast with that of the mixtures containing structured lipids. A combination of size distribution, zeta potential, and dynamic surface tension measurements proved to be useful for an adequate tracking of the kinetic stability of total nutrient admixtures. Structured triglycerides not only provide advantageous metabolic effects but improve the physical stability of total parenteral nutrition admixtures.

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“…Figure 3 showed three DLS analysis results for the solution of PM loaded with 20% DTX as a volume-weighed distribution, an intensityweighed distribution and a number-weighed distribution respectively, all of which are monodisperse unimodal pattern and almost consistent with the other two curves. Based on the DLS theories, 19) DTX-PMs have a very narrow distribution, and thus are uniform and stable nanoparticles. By comparing the size of loaded and unloaded DTX drug micelles, the size increased a little when DTX was loaded in self-assembly micelles ( Table 1).…”

Section: Resultsmentioning

confidence: 99%

A Novel Monomethoxy Polyethylene Glycol–Polylactic Acid Polymeric Micelles with Higher Loading Capacity for Docetaxel and Well-Reconstitution Characteristics and Its Anti-metastasis Study

Yang

Chen

et al. 2012

CHEMICAL & PHARMACEUTICAL BULLETIN

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Docetaxel (DTX) is hydrophobic, and its available formulations (Taxotereis a Tween80-free formulation of DTX, which has been extensively studied but rarely involved with industrialization issues. In this work, novel DTX-PM with improved loading capacity and well-reconsitution ability was developed. The freeze-dried DTX-PM was analyzed by HPLC, transmission electron microscopy (TEM) and dynamic light scattering (DLS) to determine the DTX loading, micelle morphology and size respectively. The in vitro cytotoxic activity of DTX-PM in 4T1 cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the corresponding in vivo study was assessed in BALB/c mice bearing 4T1 tumor through intravenous administration. The DTX-loading and efficiency into the micelles were 20.74 1.23% and 93.7 1.03% respectively, which was much higher than ever reported PM. The DTX-PM was spherical with a mean particle size of 16.62 0.31 nm, which suggested that they were able to selectively accumulate in solid tumors by enhanced permeability and retention (EPR) effect. Another important characteristic of DTX-PM is the long term storage and reuses as aqueous injection solution. Many kinds of lyoprotectants were also investigated and dextrose was found to an excellent one. Compared with Duopafei ® , DTX-PM showed better cytotoxicity and anti-metastasis ability against 4T1 cells in vitro and in vivo. In conclusion, DTX-PM significantly enhanced drug-loading capacity of DTX and had well-reconsitution ability, which could be a promising drug delivery system for clinic.

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Physicochemical assessments of parenteral lipid emulsions: light obscuration versus laser diffraction

Cited by 75 publications

References 8 publications

Systemic and Forearm Triglyceride Metabolism

Systemic and Forearm Triglyceride Metabolism

Tracking of the kinetic stability of 2 types of total nutrient admixtures containing different lipid emulsions

A Novel Monomethoxy Polyethylene Glycol–Polylactic Acid Polymeric Micelles with Higher Loading Capacity for Docetaxel and Well-Reconstitution Characteristics and Its Anti-metastasis Study

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