@article { ISI:000244119200031,
	title = {Designing a self-associated cationic polymer for enhanced compatibility, palatability, and gastric release of cefuroxime axetil},
	journal = {Biomacromolecules},
	volume = {8},
	number = {2},
	year = {2007},
	month = {FEB},
	pages = {532-542},
	publisher = {AMER CHEMICAL SOC},
	type = {Article},
	address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA},
	abstract = {<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>},
	issn = {1525-7797},
	doi = {10.1021/bm060673v},
	author = {Menjoge, Anupa R. and Kulkarni, Mohan G.}
}
@article { ISI:000250060600014,
	title = {Mechanistic investigations of phase behavior in Eudragit (R) blends},
	journal = {International Journal of Pharmaceutics},
	volume = {343},
	number = {1-2},
	year = {2007},
	month = {OCT},
	pages = {106-121},
	publisher = {ELSEVIER SCIENCE BV},
	type = {Article},
	address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	abstract = {<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>},
	keywords = {degree of swelling, Glass transition temperature, miscibility, polyelectrolyte complex, polymer blends, polymer-polymer interactions},
	issn = {0378-5173},
	doi = {10.1016/j.ijpharm.2007.05.033},
	author = {Menjoge, Anupa R. and Kulkarni, M. G.}
}
