PMID- 12628330
OWN - NLM
STAT- MEDLINE
DCOM- 20031017
LR  - 20190916
IS  - 0168-3659 (Print)
IS  - 0168-3659 (Linking)
VI  - 88
IP  - 2
DP  - 2003 Mar 7
TI  - Sustained release of human growth hormone from microcapsules prepared by a 
      solvent evaporation technique.
PG  - 229-42
AB  - Biodegradable microcapsules for sustained release of recombinant human growth 
      hormone (rhGH) were prepared by a solid-in-oil-in-water (S/O/W) emulsion solvent 
      evaporation technique using lyophilized protein microparticles. The minimum mean 
      particle size of rhGH in S/O dispersions was 2.8-3.0 microm when ammonium acetate 
      was added at molar ratios of 10-20 times against rhGH. High entrapment of rhGH in 
      microcapsules was achieved by incorporating rhGH powder with a smaller particle 
      size obtained by lyophilizing with ammonium acetate. As the particle size of rhGH 
      decreased, the in vivo initial release decreased, while subsequent serum levels 
      of rhGH in sustained release phase were higher. Addition of zinc oxide to 
      microcapsules resulted in higher serum levels than those prepared without zinc 
      oxide, suggesting a stabilizing effect of zinc oxide after subcutaneous injection 
      into rats. The release profile of rhGH from microcapsules was controllable by 
      selecting the proper copoly(DL-lactic/glycolic)acid (PLGA) with L/G ratio and 
      molecular weight. Utilization of rhGH powder with a smaller particle size 
      obtained by lyophilizing with ammonium acetate is essential for preparation of 
      microcapsules with high entrapment and well-controlled sustained release profile 
      with small initial release.
FAU - Takada, Shigeyuki
AU  - Takada S
AD  - Drug Formulation Research Laboratories, Takeda Chemical Industries, Ltd., 
      2-17-85, Juso-honmachi, Yodogawa-ku, Osaka 532-8686, Japan. 
      takada_shigeyuki@takeda.co.jp
FAU - Yamagata, Yutaka
AU  - Yamagata Y
FAU - Misaki, Masafumi
AU  - Misaki M
FAU - Taira, Keiko
AU  - Taira K
FAU - Kurokawa, Tomofumi
AU  - Kurokawa T
LA  - eng
PT  - Journal Article
PL  - Netherlands
TA  - J Control Release
JT  - Journal of controlled release : official journal of the Controlled Release 
      Society
JID - 8607908
RN  - 0 (Acetates)
RN  - 0 (Capsules)
RN  - 0 (Delayed-Action Preparations)
RN  - 0 (Emulsions)
RN  - 0 (Powders)
RN  - 0 (Solvents)
RN  - 9002-72-6 (Growth Hormone)
RN  - J41CSQ7QDS (Zinc)
RN  - RRE756S6Q2 (ammonium acetate)
SB  - IM
MH  - Acetates/chemistry
MH  - Animals
MH  - Capsules
MH  - Delayed-Action Preparations
MH  - Drug Compounding/methods
MH  - Emulsions
MH  - Freeze Drying
MH  - Growth Hormone/*administration & dosage/pharmacokinetics
MH  - Humans
MH  - Injections, Subcutaneous
MH  - Male
MH  - Microscopy, Electron, Scanning
MH  - Particle Size
MH  - Powders
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Solvents
MH  - Zinc/administration & dosage/pharmacokinetics
EDAT- 2003/03/12 04:00
MHDA- 2003/10/18 05:00
CRDT- 2003/03/12 04:00
PHST- 2003/03/12 04:00 [pubmed]
PHST- 2003/10/18 05:00 [medline]
PHST- 2003/03/12 04:00 [entrez]
AID - S0168365902004947 [pii]
AID - 10.1016/s0168-3659(02)00494-7 [doi]
PST - ppublish
SO  - J Control Release. 2003 Mar 7;88(2):229-42. doi: 10.1016/s0168-3659(02)00494-7.