PMID- 16054683
OWN - NLM
STAT- MEDLINE
DCOM- 20060208
LR  - 20061115
IS  - 0142-9612 (Print)
IS  - 0142-9612 (Linking)
VI  - 27
IP  - 4
DP  - 2006 Feb
TI  - Number-concentration of nanoparticles in liposomal and polymeric multiparticulate 
      preparations: empirical and calculation methods.
PG  - 651-9
AB  - The actual number of particles in formulations of nanoparticles (NP) is of 
      importance for quality assurance, comprehensive physicochemical characterization, 
      and pharmacodynamics. Some calculation methods that have been previously employed 
      are limited because they rely on several assumptions and are not applicable for 
      certain preparations. Currently there are no validated experimental methods for 
      determining the particle number-concentration (Nc) of liposomal and polymeric 
      nanoparticulate preparations (<500 nm). This study examines a new empirical 
      method for counting the number of particles in nanoparticulate formulations 
      including drug-containing liposomes and polymeric NP. In the new method, 
      suspended NP are nebulized to form aerosol droplets which are dried and counted 
      using a scanning mobility particle sizer (SMPS). Experiments were conducted with 
      three different preparations, empty liposomes (200 and 400 nm), drug-loaded 
      liposomes (200 nm), and polymeric NP (150 nm). It was verified that no 
      detrimental morphological or structural changes of the formulations have been 
      induced by the SMPS technique, and that the obtained Nc values represent the 
      original particles. It is concluded that nano-formulations with concentrations of 
      up to 10(7) particles per 1 cm3 air, corresponding to approximately 10(12) 
      particles per 1 ml solution, can be directly counted within the size range of 
      30-900 nm. The measured values are compared to newly developed theoretical 
      calculations to assess the viability of these calculations.
FAU - Epstein, Hila
AU  - Epstein H
AD  - School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Box 
      12065, Jerusalem 91120, Israel.
FAU - Afergan, Eyal
AU  - Afergan E
FAU - Moise, Tamar
AU  - Moise T
FAU - Richter, Yoram
AU  - Richter Y
FAU - Rudich, Yinon
AU  - Rudich Y
FAU - Golomb, Gershon
AU  - Golomb G
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20050728
PL  - Netherlands
TA  - Biomaterials
JT  - Biomaterials
JID - 8100316
RN  - 0 (Colloids)
RN  - 0 (Liposomes)
RN  - 0 (Polymers)
SB  - IM
MH  - Algorithms
MH  - Colloids/*analysis/chemistry
MH  - Liposomes/*analysis/chemistry
MH  - Microchemistry/*methods
MH  - Microfluidic Analytical Techniques/*methods
MH  - Molecular Weight
MH  - Nanotechnology/methods
MH  - Nanotubes/*analysis/chemistry
MH  - Particle Size
MH  - Polymers/*analysis/chemistry
MH  - Ultrafiltration/*methods
EDAT- 2005/08/02 09:00
MHDA- 2006/02/09 09:00
CRDT- 2005/08/02 09:00
PHST- 2005/02/06 00:00 [received]
PHST- 2005/06/20 00:00 [accepted]
PHST- 2005/08/02 09:00 [pubmed]
PHST- 2006/02/09 09:00 [medline]
PHST- 2005/08/02 09:00 [entrez]
AID - S0142-9612(05)00574-0 [pii]
AID - 10.1016/j.biomaterials.2005.06.006 [doi]
PST - ppublish
SO  - Biomaterials. 2006 Feb;27(4):651-9. doi: 10.1016/j.biomaterials.2005.06.006. Epub 
      2005 Jul 28.