title: Effect of microemulsion formulation on biodistribution of99mTc-Aprotinin in acute pancreatitis models induced rats.
abstract: BACKGROUND
  Aprotinin is a monomeric globular polypeptide, which derived from bovine lung tissue and theoretically attractive molecule in ameliorating the effects of acute pancreatitis. Acute pancreatitis is an inflammatory condition of the pancreas that is painful and at times deadly. Over the following two decades Aprotinin therapeutic potential on pancreatitis is proven experimentally, its clinical therapeutic success is limited due to low targeting to pancreas.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the biodistribution of Technetium-99m (99mTc)-Aprotinin solution (99mTc-Aprotinin-S) and99mTc-Aprotinin loaded microemulsion, which was prepared for the aim of treatment for acute pancreatitis.
  
  
  METHODS
  Aprotinin was radiolabeled with99mTc. Radiochemical purity was determined with radioactive thin layer chromatography studies.99mTc-Aprotinin-S and99mTc-Aprotinin loaded microemulsion (99mTc-Aprotinin-M) was administered to acute edematous, severe necrotizing pancreatitis and air pouch model induced rats. Tissue distribution of Aprotinin was investigated with gamma scintigraphy and biodistribution studies.
  
  
  RESULTS
  Aprotinin was radiolabeled by99mTc with high radiochemical purity (95.430 ± 0.946%). The complex was found to be stable at room temperature up to 6 h. Animal studies have shown that similar to that of other small proteins Aprotinin is accumulated primarily in the kidney. The scintigraphy and biodistribution studies showed that, while i.v. administration of99mTc-Aprotinin-S distributed mostly in kidneys and bladder,99mTc-Aprotinin-M, with droplet size of 64.550 ± 3.217 nm, has high uptake in liver, spleen and pancreas.
  
  
  CONCLUSIONS
  This might be concluding that microemulsions may be suggested as promising formulations for selectively targeting Aprotinin to pancreas inflammation.
authors.affiliation: a Department of Radiopharmacy , Faculty of Pharmacy, Ege University , Izmir , Turkey.
authors.forename: Derya
authors.initials: D
authors.lastname: İlem-Özdemir
authors.affiliation: b Department of Pharmaceutical Technology , School of Pharmacy, Istanbul Medipol University , Istanbul , Turkey.
authors.forename: Neslihan
authors.initials: N
authors.lastname: Üstündağ-Okur
authors.affiliation: c Department of Pharmaceutical Technology , Faculty of Pharmacy , and.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Ay Şenyiğit
authors.affiliation: d Department of Gastroenterology , Faculty of Medicine, Ege University , Izmir , Turkey.
authors.forename: Nevin
authors.initials: N
authors.lastname: Oruç
authors.affiliation: a Department of Radiopharmacy , Faculty of Pharmacy, Ege University , Izmir , Turkey.
authors.forename: Makbule
authors.initials: M
authors.lastname: Aşıkoğlu
authors.affiliation: d Department of Gastroenterology , Faculty of Medicine, Ege University , Izmir , Turkey.
authors.forename: Ömer
authors.initials: Ö
authors.lastname: Özütemiz
authors.affiliation: c Department of Pharmaceutical Technology , Faculty of Pharmacy , and.
authors.forename: H Yeşim
authors.initials: HY
authors.lastname: Karasulu
mesh_terms: D000818:Animals; D007611:Aprotinin / Q000378:metabolism*; D002626:Chemistry, Pharmaceutical / Q000379:methods; D004195:Disease Models, Animal; D004655:Emulsions / Q000378:metabolism*; D008297:Male; D010195:Pancreatitis / Q000378:metabolism*; D010316:Particle Size; D011877:Radionuclide Imaging / Q000379:methods; D019275:Radiopharmaceuticals / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013667:Technetium / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D004655:Emulsions; D019275:Radiopharmaceuticals; D013667:Technetium; D007611:Aprotinin
keywords: Aprotinin; biodistribution; microemulsion; pancreatitis; radiolabeled Aprotinin