title: Release behaviour and biocompatibility of drug-loaded pH sensitive particles.
abstract: The purpose of this work was to investigate the physical properties of drug-loaded poly(methacrylic acid-g-ethylene glycol) {P(MAA-g-EG)} particles, their biocompatibility with the gastrointestinal tract of rats and also the effects of these particles on the tight junctions of the rat intestinal epithelium. Model drugs such as diltiazem HCl, diclofenac Na, ciprofloxacin HCl and isoniazid were used in this study. P(MAA-g-EG) particles were prepared by free radical solution polymerization of methacrylic acid (MAA) and poly(ethylene glycol) (PEG). The loading efficiency of the model drugs in the particles and in vitro release profiles were investigated in pH 7.4 phosphate buffer and in gradually pH changing buffers (pH 1.2, 5.8, 6.8 and 7.4). The stability of free particles and drug-loaded particles was established by Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). In conclusion, P(MAA-g-EG) particles controlled the release rate of small molecular weight model drugs according to the pH of the medium. Stability of those particles loaded with drugs did not change in accelerated stability conditions. Histopathological results indicated that loading drugs to the particles prevented cell and tissue damage after 20 h. Free particles showed no change of tight junctions after 2 and 10 h. The results of TEM showed that increasing the amount of P(MAA-g-EG) particles from 100 to 385 mg clearly opened the tight junction, but with serious epithelial cell disruption.
authors.affiliation: Marmara University, Faculty of Pharmacy, Department of Pharmaceutical Technology, 34668 Istanbul, Turkey.
authors.forename: Oya
authors.initials: O
authors.lastname: Sipahigil
authors.forename: Ayla
authors.initials: A
authors.lastname: Gürsoy
authors.forename: Fulya
authors.initials: F
authors.lastname: Cakalağaoğlu
authors.forename: Imer
authors.initials: I
authors.lastname: Okar
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004008:Diclofenac / Q000008:administration & dosage / Q000737:chemistry* / Q000633:toxicity; D004110:Diltiazem / Q000008:administration & dosage / Q000737:chemistry* / Q000633:toxicity; D004337:Drug Carriers; D004355:Drug Stability; D017629:Gap Junctions / Q000187:drug effects / Q000473:pathology; D006863:Hydrogen-Ion Concentration; D007082:Ileum / Q000187:drug effects / Q000473:pathology; D007538:Isoniazid / Q000008:administration & dosage / Q000737:chemistry* / Q000633:toxicity; D046529:Microscopy, Electron, Transmission; D008970:Molecular Weight; D010316:Particle Size; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000737:chemistry* / Q000633:toxicity; D011109:Polymethacrylic Acids / Q000008:administration & dosage / Q000737:chemistry* / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D012995:Solubility; D013997:Time Factors
chemical_list: D004337:Drug Carriers; D011109:Polymethacrylic Acids; C099679:poly(methacrylic acid-ethylene glycol); D004008:Diclofenac; D011092:Polyethylene Glycols; D004110:Diltiazem; D007538:Isoniazid