TY - JOUR
T1 - Prolonged local anesthetic action through slow release from poly(lactic acid co castor oil)
AU - Sokolsky-Papkov, Marina
AU - Golovanevski, Ludmila
AU - Domb, Abraham J.
AU - Weiniger, Carolyn F.
PY - 2009/1
Y1 - 2009/1
N2 - Purpose. To evaluate a new formulation of bupivacaine loaded in an injectable fatty acid based biodegradable polymer poly(lactic acid co castor oil) in prolonging motor and sensory block when injected locally. Materials and methods. The polyesters were synthesized from dl-lactic acid and castor oil with feed ratio of 4:6 and 3:7 w/w. Bupivacaine was dispersed in poly(fatty ester) liquid and tested for drug release in vitro. The polymer p(DLLA:CO) 3:7 loaded with 10% bupivacaine was injected through a 22G needle close to the sciatic nerve of ICR mice and the duration of sensory and motor nerve blockade was measured. Results. The dl-lactic acid co castor oil p(DLLA:CO) 3:7 released 65% of the incorporated bupivacaine during 1 week in vitro. Single injection of 10% bupivacaine loaded into this polymer caused motor block that lasted 24 h and sensory block that lasted 48 h. Conclusion. Previously we developed a ricinoleic acid based polymer with incorporated bupivacaine which prolonged anesthesia to 30 h. The new polymer poly(lactic acid co castor oil) 3:7 provides slow release of effective doses of the incorporated local anesthetic agent and prolongs anesthesia to 48 h.
AB - Purpose. To evaluate a new formulation of bupivacaine loaded in an injectable fatty acid based biodegradable polymer poly(lactic acid co castor oil) in prolonging motor and sensory block when injected locally. Materials and methods. The polyesters were synthesized from dl-lactic acid and castor oil with feed ratio of 4:6 and 3:7 w/w. Bupivacaine was dispersed in poly(fatty ester) liquid and tested for drug release in vitro. The polymer p(DLLA:CO) 3:7 loaded with 10% bupivacaine was injected through a 22G needle close to the sciatic nerve of ICR mice and the duration of sensory and motor nerve blockade was measured. Results. The dl-lactic acid co castor oil p(DLLA:CO) 3:7 released 65% of the incorporated bupivacaine during 1 week in vitro. Single injection of 10% bupivacaine loaded into this polymer caused motor block that lasted 24 h and sensory block that lasted 48 h. Conclusion. Previously we developed a ricinoleic acid based polymer with incorporated bupivacaine which prolonged anesthesia to 30 h. The new polymer poly(lactic acid co castor oil) 3:7 provides slow release of effective doses of the incorporated local anesthetic agent and prolongs anesthesia to 48 h.
KW - Analgesia
KW - Local anesthetic
KW - Long-acting
KW - Mice
KW - Polymer-bupivacaine
UR - http://www.scopus.com/inward/record.url?scp=57749170261&partnerID=8YFLogxK
U2 - 10.1007/s11095-008-9699-8
DO - 10.1007/s11095-008-9699-8
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C2 - 18719979
AN - SCOPUS:57749170261
SN - 0724-8741
VL - 26
SP - 32
EP - 39
JO - Pharmaceutical Research
JF - Pharmaceutical Research
IS - 1
ER -