02242nas a2200157   4500008004100000022001400041245013200055210006900187260007100256300001200327490000600339520156200345100002301907700002401930856013001954       2007                        eng d  a1525-779700aDesigning a self-associated cationic polymer for enhanced compatibility, palatability, and gastric release of cefuroxime axetil0 aDesigning a selfassociated cationic polymer for enhanced compati  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a532-5420 v83 a<p>Cefuroxime axetil (CA) has exhibited interactions with the polymers hydroxypropyl methylcellulose phthalate, cellulose acetate trimellitate, and Eudragit E resulting in the generation of unacceptable amounts of impurities and degradation. Formulations, which mask the bitter taste of CA and release it immediately in the stomach, have therefore not been possible. In an attempt to overcome the interaction with CA, we report a self-associated cationic polymer (NREP) containing methyl methacrylate (MMA), 2-hydroxy ethylmethacrylate (HEMA), and 4-vinyl pyridine (4-VP). The hydrogen bonding between the pyridine nitrogen and the hydroxyl groups of HEMA results in strong intrachain associations, prevents interactions between NREP and CA, and inhibits degradation of CA. This has been validated by differential scanning calorimetry, Fourier transform infrared spectroscopy, NMR, and high-performance liquid chromatography analysis. These self-associations restrict polymer chain motions, enhance biocompatibility, and lead to a higher T-g, which ensures that NREP does not become tacky in processes involving heat. The judicious choice of the hydrophobic and hydrophilic monomers renders the polymer hydrophobic enough as to mask the bitter taste of CA at near neutral pH. Incorporation of the basic monomer 4-VP ensures rapid dissolution of the polymer and release of CA at the acidic pH prevalent in the stomach. The work indicates an approach to design pH-sensitive polymers for dosage forms that meet the pharmacokinetic requirements of the drug.</p>1 aMenjoge, Anupa, R.1 aKulkarni, Mohan, G.  uhttps://library.ncl.res.in/content/designing-self-associated-cationic-polymer-enhanced-compatibility-palatability-and-gastric01859nas a2200229   4500008004100000022001400041245007200055210006900127260007300196300001200269490000800281520104300289653002301332653003301355653001601388653002801404653001901432653003301451100002301484700002101507856010101528       2007                        eng d  a0378-517300aMechanistic investigations of phase behavior in Eudragit (R) blends0 aMechanistic investigations of phase behavior in Eudragit R blend  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT  a106-1210 v3433 a<p>Blends of Eudragit (R) E (EE) and polymeric excipients using thermal analysis and FTIR spectroscopy were examined. The interactions amongst the blend components were quantified in terms of parameters K-1 and K-2 in Schneider equation and were explained on the basis of interactions between the functional groups of the blend constituents investigated by FTIR spectroscopy. EE formed miscible blends with EC and polyelectrolyte complexes increasing in strength in the order: ES &lt; HPMCP &lt; CAP &lt; EL. From the T-g data the weight fraction of EE in the polyelectrolyte complex was determined. The importance of formulating polyelectrolyte complexes in stoichiometric ratios has been highlighted. The duration over which the release can be sustained by polyelectrolyte complexes has been correlated with equilibrium swelling of the polyelectrolyte complex and parameter K, for the first time. This would help in the choice of blend constituents and composition to tailor drug release. (C) 2007 Elsevier B.V. All rights reserved.</p>10adegree of swelling10aGlass transition temperature10amiscibility10apolyelectrolyte complex10apolymer blends10apolymer-polymer interactions1 aMenjoge, Anupa, R.1 aKulkarni, M., G.  uhttps://library.ncl.res.in/content/mechanistic-investigations-phase-behavior-eudragit-r-blends-0