Lipid and doxorubicin concentrations were quantified by HPLC.
| Components | Interview Form of DOXIL® | Assay Values | % of Total Lipid |
|---|---|---|---|
| HSPC | 9.58 mg/mL | 9.74 mg/mL | 59.6% |
| Cholesterol | 3.19 mg/mL | 3.27 mg/mL | 20.0% |
| MPEG2000-DSPE | 3.19 mg/mL | 3.33 mg/mL | 20.4% |
| doxorubicin | 2.00 mg/mL | 2.00 mg/mL | - |
In order to measure the encapsulation rate of doxorubicin, the obtained liposomes were ultracentrifuged and the liposome fraction was collected. The doxorubicin concentration was quantified by HPLC, and the concentration of doxorubicin encapsulated in the liposomes was measured.
The percentage of encapsulated Doxorubicin in DOXIL® from Presome ACD-1: 100%
The average particle size, polydispersity index [PDI], and zeta potential of the obtained liposome solution were measured by dynamic scattering light analysis using Malvern Nano-ZS.
Enlarge illustrationFrom the slope of the approximate curve of In ζ-potential vs. Debye-Huckel parameter plot 1], the thickness of the hydrated layer on the surface of the liposome was measured.
| NaCl Conc. [C] | ζ-potential |
|---|---|
| 0 M | -36.05±2.20㎷ |
| 0.005 M | -19.36±0.25㎷ |
| 0.010 M | -15.06±1.04㎷ |
| 0.015 M | -12.26±1.79㎷ |
| 0.050 M | -7.22±1.12㎷ |
| 0.100 M | -4.75±1.14㎷ |
The thickness of the fixed aqueous layer of DOXIL® from Presome ACD-1: 2.1㎚
1] K. Shimada, A. Miyagishima, Y. Sadzuka, Y. Nozawa, Y. Mochizuki, H. Ohshima and S. Hirota, Determination of the thickness of the fixed aqueous layer around polyethyleneglycol-coated liposomes. Journal of Drug Targeting, 1995, 3, 283
Negative staining: The samples were let to absorbed 400 mesh carbon coated grid and were put into 2% phospho tungstic acid solution [㏗7.0] for a few seconds.
Observation and imaging: The samples were observed by a transmission electron microscope [JEM-1200EX; JEOL Ltd.,] at an acceleration voltage of 80㎸.
Digital images [2048x2048 pixels] were taken with a CCD camera [VELETA, Olympus Soft Imaging Solutions GmbH].
As described above, we were able to prepare single membrane liposomes using Presome. In addition, most of the drug was retained in the liposome aqueous layer, and the lipid / drug composition, average particle size, particle distribution, and hydration layer thickness were shown to be equivalent to DOXIL®.
Based on these facts, it is considered that even if Presome is used, a liposomal drug equivalent to DOXIL® can be produced.
※2 - 4 will be repeated as necessary.
In the Nippon Fine Chemical Lipit Department, we have experienced encapsulating drugs in many liposomes using our abundant high-purity phospholipid series.
The Presome series is also available to provide services tailored to customer needs.
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We own a variety of liposome production equipment that can handle small to medium scales, so we can meet your diverse needs for liposome development.
