[Study on pulmonary delivery system of salmon calcitonin in rats].
OBJECTIVE
To study the serum calcitonin(CT) levels in vivo after pulmonary delivery to rats and the effects of absorption enhancers.


METHODS
Salmon calcitonin (sCT) solution was delivered by intramuscular injection or intratracheal administration to rats. The absorption of sCT was determined by radioimmunoassay method. Changes in serum drug levels after the pulmonary administration of sCT with various absorption enhancers or in different pH conditions were investigated.


RESULTS
Compared with intramuscular administration, the relative bioavailability of sCT solution (2 micrograms.kg-1) given by intratracheal route was 121.0%. Transpulmonary absorption of sCT solution, with some absorption enhancers (Brij78, sodium cholate, lecithin, chitosan and sodium caprylate) or under acidic conditions (pH3.0), was significantly greater than the values obtained in controls.


CONCLUSIONS
sCT solution showed higher bioavailability after pulmonary administration.
Wang
Zhiying
Z
Department of Pharmaceutics, Peking University School of Pharmaceutical Sciences, Beijing 100083, China.
Zhang
Qiang
Q
D000818:Animals; D001682:Biological Availability; D002116:Calcitonin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D006863:Hydrogen-Ion Concentration; D008168:Lung / Q000378:metabolism*; D010539:Permeability; D051381:Rats
C028815:salmon calcitonin; D002116:Calcitonin