Examination of biodegradability of poly(ethylene carbonate) and poly(propylene carbonate) in the peritoneal cavity in rats.

Kawaguchi, Takeo; Nakano, Masahiro; Juni, Kazuhiko; Inoue, Shohei; Yoshida, Yasuhiko

doi:10.1248/cpb.31.1400

Cited by 83 publications

(48 citation statements)

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“…The difference between i n uiuo and in uitro has been explained by enzymatic activity in the former case. 27 We have seen by in uiuo (rat) study of PTMC samples from the same batch as PTMC-HMW1 series (Table I ) that the material is not affected by the biological environment during an implantation time of 180 days. The molecular weight and molecular weight distribution were unchanged and, consequently, no weight loss was detected.…”

Section: Molecular Weight Changesmentioning

confidence: 94%

“…24 Pitt and co-workers have studied the in vitro and in vivo degradation of poly (trimethylene carbonate) , 25 and trimethylene carbonate/DL-lactide copolymer has been evaluated by Buchholz.26 Previous studies concerning the degradation of aliphatic polycarbonates are mostly done on shorter homologs than poly (trimethylene carbonate) . 27 The degradation of aliphatic polyester structures are recognized today to be dominated by a hydrolytic mechanism, but is also regarded to be promoted by enzymatic activity. 25,2'-31 The divergent opinions arose as a difference in degradation behavior that has been detected between in vitro and in vivo experiments for some polymers.…”

Section: Introductionmentioning

confidence: 99%

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Influence of molecular structure on the degradation mechanism of degradable polymers: In vitro degradation of poly(trimethylene carbonate), poly(trimethylene carbonate‐co‐caprolactone), and poly(adipic anhydride)

Albertsson

Eklund

1995

J of Applied Polymer Sci

184

154

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SYNOPSISRelationships between molecular structure and the degradation mechanism of degradable polymers are of special interest for temporary medical applications. The in uitro degradation study of three aliphatic polymers-poly(trimethy1ene carbonate) (PTMC), poly-(trimethylene carbonate-co-caprolactone) (PTMC-PCL), and poly(adipic anhydride) (PAA)-revealed that these polymers exhibit degradation times from several years (PTMC) to 1 day (PAA). PTMC degraded unexpectedly slow, accompanied by very small changes in weight loss, molecular weight (SEC), and in morphology (DSC, SEM). The degradation was independent of initial molecular weight, ionic strength of the water solution, temperature, and shaking motions. The copolymer PTMC-PCL showed a higher degradation rate compared to PTMC, with preferential degradation of amorphous parts leading to an increase in % crystallinity. The surprisingly rapid degradation of PAA showed characteristics typical for a surface-like eroding system in contrast to PTMC and PTMC-PCL. The degradation products corresponded to the repeating unit of the polymers. The hydrolysis rate increases in the order carbonate, ester, anhydride, and by combining different molecular structures we achieve specific degradation behavior. A change in hydrolysis rate of the labile bond is predicted by altering the electronegativity of groups near the carbonyl-oxygen region. 0 1995 John Wiley & Sons, Inc.

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Section: Molecular Weight Changesmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Influence of molecular structure on the degradation mechanism of degradable polymers: In vitro degradation of poly(trimethylene carbonate), poly(trimethylene carbonate‐co‐caprolactone), and poly(adipic anhydride)

Albertsson

Eklund

1995

J of Applied Polymer Sci

184

154

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“…Kawaguchi 19) found that poly(ethylene carbonate) was degradable in the body while poly (propylene carbonate) was not. In the mixture of poly(ethylene carbonate) and poly(propylene carbonate), 20) degradation rate increased with contents of poly(ethylene carbonate) (Fig. 3).…”

Section: Examination Of Biodegradable Polymers For Sustained Drug Relmentioning

confidence: 93%

From Physical Pharmacy to Clinical Pharmacology

Nakano

2005

YAKUGAKU ZASSHI

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Research works on molecular interactions in solutions were carried out at School of Pharmacy, the University of Wisconsin under the direction of Prof. T. Higuchi and at Faculty of Pharmaceutical Sciences, Kyoto University under the direction of Prof. H. Sezaki. Studies on permeation of drugs through polymer membranes were carried out at Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada and at Pharmaceutical Chemistry Research Laboratories at Food and Drug Directorate, Department of Health and Welfare, Canada. Studies on modiˆcation of delivery patterns by means of pharmaceutical approaches were carried out at Faculty of Pharmaceutical Sciences, Hokkaido University. Topics related to modiˆcation of drug delivery patterns include employment of amorphous forms such as ground mixture with micro-crystalline cellulose and coprecipitate with polyvinylpyrrolidone, use of biodegradable polymers such as polylactic acid and polycarbonates, gel-forming materials such as konjac, agar and hydroxypropylcellulose, and physicochemical systems such as complexation. Works related to drug delivery and disposition of drugs in humans were carried out at Department of Pharmacy, Kumamoto University Hospital. Topics related to drug delivery in humans include injections containing anticancer drugs for intra-arterial administration, lidocaine gels for dermal anesthesia, glucagon solution for nasal administration. Topics related to disposition of drugs in humans include clinical pharmacokinetic studies in infants and elderly and medical uses of adsorbents.

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“…[1][2][3][4][5][6][7][8] Moreover, it has become the potential compound for the non-phosgene synthesis of isocyanate via thermal decomposition. Unfortunately, till today, the most convenient method for the synthesis of these products is the aminolysis of chloroformate, which is produced from phosgene and alcohols.…”

Section: Introductionmentioning

confidence: 99%

Atom‐economy Synthesis of N‐Substituted Carbamate from Urea Derivative and Dimethyl Carbonate Catalyzed by La/SiO₂: Characterization and Activity

Guo

Shang

et al. 2010

Chin. J. Chem.

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A series of silica gel immobilized lanthanum catalysts were prepared for the atom-economy synthesis of N-substituted carbamates from urea derivatives and dimethyl carbonate. The La/SiO 2 catalysts with lanthanum loadings varied from 1.3 wt% to 8.5 wt% were characterized by AES, BET, XRD, TEM, FT-IR, XPS and TPD. According to the characterization, lanthanum species with particle sizes of 5-10 nm on the surface of silica gel were formed. The catalysts were all amorphous and the surface areas were 336.5-530.2 m 2 /g. NH 3 -TPD analysis showed that all samples exhibited similar acid strength with different acid amounts. FT-IR measurement indicated that the component of lanthanum species on the catalyst surface were La(OH) 3 , LaOOH and hydrated La 2 O 3 . Also, the peak value of the absolute amount of LaOOH was obtained with 4.3 wt% lanthanum loading. The BET surface area decreased dramatically when the lanthanum loading was above 4.3 wt%. In consideration of the results obtained from the catalytic reactions, it could be concluded that LaOOH was the possible active species and high surface area was important for the high catalytic activity.

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Examination of biodegradability of poly(ethylene carbonate) and poly(propylene carbonate) in the peritoneal cavity in rats.

Cited by 83 publications

References 0 publications

Influence of molecular structure on the degradation mechanism of degradable polymers: In vitro degradation of poly(trimethylene carbonate), poly(trimethylene carbonate‐co‐caprolactone), and poly(adipic anhydride)

Influence of molecular structure on the degradation mechanism of degradable polymers: In vitro degradation of poly(trimethylene carbonate), poly(trimethylene carbonate‐co‐caprolactone), and poly(adipic anhydride)

From Physical Pharmacy to Clinical Pharmacology

Atom‐economy Synthesis of N‐Substituted Carbamate from Urea Derivative and Dimethyl Carbonate Catalyzed by La/SiO₂: Characterization and Activity

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Examination of biodegradability of poly(ethylene carbonate) and poly(propylene carbonate) in the peritoneal cavity in rats.

Cited by 83 publications

References 0 publications

Influence of molecular structure on the degradation mechanism of degradable polymers: In vitro degradation of poly(trimethylene carbonate), poly(trimethylene carbonate‐co‐caprolactone), and poly(adipic anhydride)

Influence of molecular structure on the degradation mechanism of degradable polymers: In vitro degradation of poly(trimethylene carbonate), poly(trimethylene carbonate‐co‐caprolactone), and poly(adipic anhydride)

From Physical Pharmacy to Clinical Pharmacology

Atom‐economy Synthesis of N‐Substituted Carbamate from Urea Derivative and Dimethyl Carbonate Catalyzed by La/SiO2: Characterization and Activity

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Atom‐economy Synthesis of N‐Substituted Carbamate from Urea Derivative and Dimethyl Carbonate Catalyzed by La/SiO₂: Characterization and Activity