Pharmacokinetics and pharmacodynamics of controlled release insulin loaded PLGA microcapsules using dry powder inhaler in diabetic rats.
The pulmonary route is an alternative route of administration for the systemic delivery of peptide and proteins with short-half lives. A long-acting formulation of insulin was prepared by encapsulation of protein into respirable, biodegradable microcapsules prepared by an oil in oil emulsification/solvent evaporation method. Insulin-loaded PLGA microcapsules prepared as a dry powder inhaler formulation were administered via the pulmonary route to diabetic rats and serum insulin and glucose concentrations were monitored. Control treatments consisted of respirable spray-dried insulin (RSDI) powder administered by intratracheal insufflation, insulin-loaded PLGA microcapsules and NPH (long-acting) insulin administered by subcutaneous (SC) administration. Pharmacokinetic analysis demonstrated that insulin administered in PLGA microcapsules illustrated a sustained release profile which resulted in a longer mean residence time, 4 and 5 fold longer than those after pulmonary administration of RSDI and SC injection of NPH insulin, respectively. Accordingly, the hypoglycemic profile followed a stable and sustained pattern which remained constant between 10 and 48 h. Results of the in vitro experiments were in good agreement with those of in vivo studies. Bronchoalveolar lavage fluid analysis indicated that microcapsules administration did not increase the activities of lactate dehydrogenase and total protein. However, histological examination of the lung tissue indicated a minor but detectable effect on the normal physiology of the rat lung. These findings suggest that the encapsulation of peptides and proteins into PLGA microcapsules technique could be a promising controlled delivery system for pulmonary administration.
Pharmaceutical Technology Laboratory, Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Hamed
H
Hamishehkar
Jaber
J
Emami
Abdolhossien Rouholamini
AR
Najafabadi
Kambiz
K
Gilani
Mohsen
M
Minaiyan
Kambiz
K
Hassanzadeh
Hamid
H
Mahdavi
Maryam
M
Koohsoltani
Ali
A
Nokhodchi
D000280:Administration, Inhalation; D000818:Animals; D001786:Blood Glucose; D002214:Capsules / Q000493:pharmacokinetics* / Q000494:pharmacology; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism*; D016503:Drug Delivery Systems; D005079:Excipients / Q000493:pharmacokinetics; D007004:Hypoglycemic Agents / Q000493:pharmacokinetics* / Q000494:pharmacology; D019344:Lactic Acid / Q000493:pharmacokinetics*; D008297:Male; D009330:Nebulizers and Vaporizers / Q000706:statistics & numerical data*; D011100:Polyglycolic Acid / Q000493:pharmacokinetics*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011208:Powders / Q000493:pharmacokinetics / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar
D001786:Blood Glucose; D002214:Capsules; D005079:Excipients; D007004:Hypoglycemic Agents; D011208:Powders; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid