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Particle Based Drug Delivery Systems
ReferencesLANGER, R.S. & PEPPAS, N.A. (1981) Present and future applications of biomaterials in controlled drug delivery systems. Biomaterials. 2, 201-214.
Week 6
POLYMER-DCM SOLUTION
ADD TO PVA IN WATER & MIX
SECONDARY EMULSION (W/O/W)
SOLVENT EVAPORATION
FILTRATION AND DRYING
PRIMARY EMULSION (W/O)
ULTRA SONICATION
PROTEIN SOLUTION
Double Emulsion Method
•Inlet temperature
•Polymer concentration
•Pump feed rate
•Aspirator ratio
•Compressed air flow rate
•Drug loadings
Spray Dried Microspheres
Microsphere surface morphology using different polymer solution concentrations
A B
DC
F.J. Wang and C.H. Wang, “Sustained Release of Etanidazole from Spray Dried Microspheres Prepared by Non-halogenated Solvents”, J. Controlled Release, 81 263-280 (2002).
Degradation of microspheres
PLGA 65:351 monthPLGA 50:50
1 month
PLGA 85:153 month
PDLA3 month
F.J. Wang, T.K.Y. Lee and C.H. Wang , “PEG Modulated Release of Etanidazole from Implantable PLGA/PDLA Discs”, Biomaterials, 23 3555-3566 (2002)..
Modulation of release by PEG
0
10
20
30
40
50
60
70
80
90
100
0 20 40 60 80 100
Release Time (days)
Cu
mu
lati
ve
Re
lea
se
(%
)
PEG 8000, 10%
PEG3350, 10%
PEG1145, 5%
PEG3350, 5%
small discs (diameter = 5mm, thickness =1mm)
0
10
20
30
40
50
60
70
80
90
100
0 20 40 60 80 100
Release Time (days)
Cu
mu
lati
ve
Re
leas
e (
%)
PEG8000 10%
PEG3350 10%
PEG1145 5%
PEG 3350 5%
large discs (diameter =13mm, thickness = 1mm)
F.J. Wang, T.K.Y. Lee and C.H. Wang , “PEG Modulated Release of Etanidazole from Implantable PLGA/PDLA Discs”, Biomaterials, 23 3555-3566 (2002).