Ammonio methacrylate copolymer

Copolymerum methacrylatis butylati basicum Polyacrylatis dispersion 30 per centum USPNF Ammonio methacrylate copolymer... 

The USPNF 23 describes methacrylic acid copolymer as a fully polymerized copolymer of methacrylic acid and an acrylic or methacrylic ester. Three types of copolymers, namely Type A, Type B, and Type C, are defined in the monograph. They vary in their methacrylic acid content and solution viscosity. Type C may contain suitable surface-active agents. Two additional polymers, Type A (Eudragit RE) and Type B (Eudragit RS), also referred to as ammonio methacrylate copolymers, consisting of fully polymerized copolymers of acrylic and methacrylic acid esters with a low content of quaternary ammonium groups, are also described in the USPNF 23. A further monograph for an aqueous dispersion of Type C methacrylic acid copolymer is also defined see Section 9. 

Huang J, Wigent RJ, Schwartz JB (2008) Drug-polymer interaction and its significance on the physical stability of nifedipine amorphous dispersion in microparticles of an ammonio methacrylate copolymer and ethylcellulose binary blend. J Pharm Sci 97 251-262. 

Chem. Descrip. Eudragit RL100 (ammonio methacrylate copolymer) and Na-CMC... 

Chem. Descrip. Ammonio methacrylate copolymer. Type A, USP/NF aq. disp. 

Ammonio methacrylate copolymer Ethocer Standard 20 Ethocel ... 

Eudragil RL PO, Eudragil RS 30 D, Eudragil RS 100, Eudragil RS PO. See Ammonio methacrylate copolymer Eudragil S 100. See Methacrylic acid copolymer... 

Ammonio methacrylate copolymer coating agent, food... 

Polymethacrylate copolymers lack the solubilizing capacity of other polymers, but are excellent matrix formers, used for the sustained release of drugs, or for enteric release, depending on polymer chemistry. The ammonio-methacrylate copolymers (Eudragit RS/RL) are insoluble but permeable by water, a property that makes them suitable for the production of sustained release pellets. Poly(methacrylic acid-co-methyl methacrylate) 1 2 (Eudragit S) and Poly(methacylic acid-co-ethyl acrylate) 1 1 (Eudragit L), on the other hand, are soluble at pH values above 6 and 7 respectively, which makes them suitable for enteric release pellets. 

Simulations of pharmaceutical relevant mixtures of polymer-drug/excipient blends, however, are scarce. Momany and Willett [25] investigated the dependence of Tg of maltodecaose on its hydration (water is known to act as a plasticizer for carbohydrates) and Yoshioka et al. [29] probed values of freeze-dried dextran cakes. Quite recently, we have studied the dependence of an ammonio methacrylate copolymer (Eudragit RS) as a function of its triethyl citrate (TEC) content [27], which was in good agreement when compared with experimental data. 

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