Suberin Fatty Acids from Outer Birch Bark: Isolation and Physical Material Characterization.
The isolation and physical material properties of suberin fatty acids (SFAs) were investigated with special reference to their potential applications as novel pharmaceutical excipients. SFAs were isolated from outer birch bark (OBB) with a new extractive hydrolysis method. The present simplified isolation process resulted in a moderate batch yield and chemical purity of SFAs, but further development is needed for establishing batch-to-batch variation. Cryogenic milling was the method of choice for the particle size reduction of SFAs powder. The cryogenically milled SFAs powder exhibited a semicrystalline structure with apparent microcrystalline domains within an amorphous fatty acids matrix. The thermogravimetric analysis (TGA) of SFAs samples showed a good thermal stability up to 200 °C, followed by a progressive weight loss, reaching a plateau at about 95% volatilization at about 470 °C. The binary blends of SFAs and microcrystalline cellulose (MCC; Avicel PH 101) in a ratio of 25:75 (w/w) displayed good powder flow and tablet compression properties. The corresponding theophylline-containing tablets showed sustained or prolonged-release characteristics. The physicochemical and bulk powder properties of SFAs isolated from OBB are auspicious in terms of potential pharmaceutical excipient applications.
Institute of Pharmacy, Faculty of Medicine, University of Tartu , Nooruse 1, 50411 Tartu, Estonia.
Jyrki
0000-0002-5996-5144
J
Heinämäki
VTT Technical Research Centre Finland Ltd , VTT Industrial Synthesis, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT, Finland.
Minni M
MM
Pirttimaa
VTT Technical Research Centre Finland Ltd , VTT Industrial Synthesis, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT, Finland.
Sami
S
Alakurtti
VTT Technical Research Centre Finland Ltd , VTT Industrial Synthesis, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT, Finland.
H Pauliina
HP
Pitkänen
VTT Technical Research Centre Finland Ltd , VTT Industrial Synthesis, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT, Finland.
Heimo
H
Kanerva
VTT Technical Research Centre Finland Ltd , VTT Industrial Synthesis, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT, Finland.
Janne
J
Hulkko
Institute of Pharmacy, Faculty of Medicine, University of Tartu , Nooruse 1, 50411 Tartu, Estonia.
Urve
U
Paaver
Department of Geology, Institute of Ecology and Earth Sciences, University of Tartu , Ravila 14a, 50411 Tartu, Estonia.
Jaan
J
Aruväli
Division of Pharmaceutical Chemistry and Technology , Faculty of Pharmacy, P.O. Box 56 (Viikinkaari 5E), FI-00014 University of Helsinki, Finland.
Jouko
J
Yliruusi
Institute of Pharmacy, Faculty of Medicine, University of Tartu , Nooruse 1, 50411 Tartu, Estonia.
Karin
K
Kogermann
D029662:Betula / Q000737:chemistry*; D002482:Cellulose; D002626:Chemistry, Pharmaceutical; D005079:Excipients / Q000494:pharmacology; D005227:Fatty Acids / Q000737:chemistry / Q000302:isolation & purification*; D008055:Lipids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D015394:Molecular Structure; D024301:Plant Bark / Q000737:chemistry*; D013607:Tablets / Q000494:pharmacology; D013806:Theophylline / Q000032:analysis
D005079:Excipients; D005227:Fatty Acids; D008055:Lipids; D013607:Tablets; C065875:suberin; D002482:Cellulose; D013806:Theophylline; C109691:microcrystalline cellulose