Study of the dispersion behaviour of L-leucine containing microparticles synthesized with an aerosol flow reactor method

Janne Raula, Juha Kurkela, David P. Brown, Esko I. Kauppinen

Research output: Contribution to journalArticleScientificpeer-review

19 Citations (Scopus)

Abstract

l-leucine containing particles having salbutamol sulphate or sodium chloride as a main component have been produced by an aerosol flow reactor method. In the method, aqueous solute droplets were transferred into a heated laminar flow reactor where droplet drying took place. The geometric number mean diameter (GNMD) of the produced particles varied between 0.50 and 1.01 μm. Amino acid l-leucine, due to its surface-active nature in water, formed the outer layer of the initial droplet and in the product composite salbutamol and NaCl powders. The morphology of the amorphous salbutamol particles changed from spherical to wrinkled and that of the crystalline NaCl particles from faceted to rounded but fractured due to incorporated l-leucine.
These powders mixed with coarse lactose powder were tested in a novel deagglomeration apparatus where they experienced continuous turbulent flows with jet flow rates from 15 to 90 l/min intended to disperse powder agglomerates. In general, the incorporation of l-leucine improved dispersion efficiency as well as decreased dependence on dispersing flow rate of all the powders.
The influence of l-leucine was observed particularly at low flow rates: The particle number concentration of the dispersed NaCl particles increased ∼ 19 times and that of the salbutamol particles ∼ 12 times with 20 wt.% of l-leucine at a flow rate of 15 l/min. Added l-leucine affected the dispersion of salbutamol particles more than that of NaCl particles due to different particle surface.
Moreover, the salbutamol-l-leucine agglomerates were reduced to the primary particles at high flow rates. This was not observed for the NaCl-l-leucine agglomerates. Fine particle fractions (FPF, D ≤ 5 μm) of NaCl-l-leucine and salbutamol-l-leucine composite particles at a flow rate of 60 l/min increased, respectively, from 0.14 to 0.29 and 0.19 to 0.39 with increasing l-leucine content. Commercial micronized salbutamol powder gave an FPF of 0.15.
Original languageEnglish
Pages (from-to)125-132
JournalPowder Technology
Volume177
Issue number3
DOIs
Publication statusPublished - 2007
MoE publication typeA1 Journal article-refereed

Fingerprint

Aerosols
Leucine
Albuterol
Flow rate
Powders
Composite materials
Sodium chloride
Laminar flow
Particles (particulate matter)
Turbulent flow
Amino acids
Drying
Crystalline materials
Lactose
Sodium Chloride
Sulfates
Water
Amino Acids

Keywords

  • dispersion
  • l-leucine
  • salbutamol sulphate
  • surface modification
  • inhalation drug delivery
  • pharmaceutical
  • dry powders

Cite this

Raula, Janne ; Kurkela, Juha ; Brown, David P. ; Kauppinen, Esko I. / Study of the dispersion behaviour of L-leucine containing microparticles synthesized with an aerosol flow reactor method. In: Powder Technology. 2007 ; Vol. 177, No. 3. pp. 125-132.
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abstract = "l-leucine containing particles having salbutamol sulphate or sodium chloride as a main component have been produced by an aerosol flow reactor method. In the method, aqueous solute droplets were transferred into a heated laminar flow reactor where droplet drying took place. The geometric number mean diameter (GNMD) of the produced particles varied between 0.50 and 1.01 μm. Amino acid l-leucine, due to its surface-active nature in water, formed the outer layer of the initial droplet and in the product composite salbutamol and NaCl powders. The morphology of the amorphous salbutamol particles changed from spherical to wrinkled and that of the crystalline NaCl particles from faceted to rounded but fractured due to incorporated l-leucine. These powders mixed with coarse lactose powder were tested in a novel deagglomeration apparatus where they experienced continuous turbulent flows with jet flow rates from 15 to 90 l/min intended to disperse powder agglomerates. In general, the incorporation of l-leucine improved dispersion efficiency as well as decreased dependence on dispersing flow rate of all the powders. The influence of l-leucine was observed particularly at low flow rates: The particle number concentration of the dispersed NaCl particles increased ∼ 19 times and that of the salbutamol particles ∼ 12 times with 20 wt.{\%} of l-leucine at a flow rate of 15 l/min. Added l-leucine affected the dispersion of salbutamol particles more than that of NaCl particles due to different particle surface. Moreover, the salbutamol-l-leucine agglomerates were reduced to the primary particles at high flow rates. This was not observed for the NaCl-l-leucine agglomerates. Fine particle fractions (FPF, D ≤ 5 μm) of NaCl-l-leucine and salbutamol-l-leucine composite particles at a flow rate of 60 l/min increased, respectively, from 0.14 to 0.29 and 0.19 to 0.39 with increasing l-leucine content. Commercial micronized salbutamol powder gave an FPF of 0.15.",
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author = "Janne Raula and Juha Kurkela and Brown, {David P.} and Kauppinen, {Esko I.}",
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Study of the dispersion behaviour of L-leucine containing microparticles synthesized with an aerosol flow reactor method. / Raula, Janne; Kurkela, Juha; Brown, David P.; Kauppinen, Esko I.

In: Powder Technology, Vol. 177, No. 3, 2007, p. 125-132.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Study of the dispersion behaviour of L-leucine containing microparticles synthesized with an aerosol flow reactor method

AU - Raula, Janne

AU - Kurkela, Juha

AU - Brown, David P.

AU - Kauppinen, Esko I.

PY - 2007

Y1 - 2007

N2 - l-leucine containing particles having salbutamol sulphate or sodium chloride as a main component have been produced by an aerosol flow reactor method. In the method, aqueous solute droplets were transferred into a heated laminar flow reactor where droplet drying took place. The geometric number mean diameter (GNMD) of the produced particles varied between 0.50 and 1.01 μm. Amino acid l-leucine, due to its surface-active nature in water, formed the outer layer of the initial droplet and in the product composite salbutamol and NaCl powders. The morphology of the amorphous salbutamol particles changed from spherical to wrinkled and that of the crystalline NaCl particles from faceted to rounded but fractured due to incorporated l-leucine. These powders mixed with coarse lactose powder were tested in a novel deagglomeration apparatus where they experienced continuous turbulent flows with jet flow rates from 15 to 90 l/min intended to disperse powder agglomerates. In general, the incorporation of l-leucine improved dispersion efficiency as well as decreased dependence on dispersing flow rate of all the powders. The influence of l-leucine was observed particularly at low flow rates: The particle number concentration of the dispersed NaCl particles increased ∼ 19 times and that of the salbutamol particles ∼ 12 times with 20 wt.% of l-leucine at a flow rate of 15 l/min. Added l-leucine affected the dispersion of salbutamol particles more than that of NaCl particles due to different particle surface. Moreover, the salbutamol-l-leucine agglomerates were reduced to the primary particles at high flow rates. This was not observed for the NaCl-l-leucine agglomerates. Fine particle fractions (FPF, D ≤ 5 μm) of NaCl-l-leucine and salbutamol-l-leucine composite particles at a flow rate of 60 l/min increased, respectively, from 0.14 to 0.29 and 0.19 to 0.39 with increasing l-leucine content. Commercial micronized salbutamol powder gave an FPF of 0.15.

AB - l-leucine containing particles having salbutamol sulphate or sodium chloride as a main component have been produced by an aerosol flow reactor method. In the method, aqueous solute droplets were transferred into a heated laminar flow reactor where droplet drying took place. The geometric number mean diameter (GNMD) of the produced particles varied between 0.50 and 1.01 μm. Amino acid l-leucine, due to its surface-active nature in water, formed the outer layer of the initial droplet and in the product composite salbutamol and NaCl powders. The morphology of the amorphous salbutamol particles changed from spherical to wrinkled and that of the crystalline NaCl particles from faceted to rounded but fractured due to incorporated l-leucine. These powders mixed with coarse lactose powder were tested in a novel deagglomeration apparatus where they experienced continuous turbulent flows with jet flow rates from 15 to 90 l/min intended to disperse powder agglomerates. In general, the incorporation of l-leucine improved dispersion efficiency as well as decreased dependence on dispersing flow rate of all the powders. The influence of l-leucine was observed particularly at low flow rates: The particle number concentration of the dispersed NaCl particles increased ∼ 19 times and that of the salbutamol particles ∼ 12 times with 20 wt.% of l-leucine at a flow rate of 15 l/min. Added l-leucine affected the dispersion of salbutamol particles more than that of NaCl particles due to different particle surface. Moreover, the salbutamol-l-leucine agglomerates were reduced to the primary particles at high flow rates. This was not observed for the NaCl-l-leucine agglomerates. Fine particle fractions (FPF, D ≤ 5 μm) of NaCl-l-leucine and salbutamol-l-leucine composite particles at a flow rate of 60 l/min increased, respectively, from 0.14 to 0.29 and 0.19 to 0.39 with increasing l-leucine content. Commercial micronized salbutamol powder gave an FPF of 0.15.

KW - dispersion

KW - l-leucine

KW - salbutamol sulphate

KW - surface modification

KW - inhalation drug delivery

KW - pharmaceutical

KW - dry powders

U2 - 10.1016/j.powtec.2007.03.016

DO - 10.1016/j.powtec.2007.03.016

M3 - Article

VL - 177

SP - 125

EP - 132

JO - Powder Technology

JF - Powder Technology

SN - 0032-5910

IS - 3

ER -