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Titolo:
Influence of admixed carboxymethylcellulose on release of 4-aminopyridine from hydroxypropyl methylcellulose matrix tablets
Autore:
Juarez, H; Rico, G; Villafuerte, L;
Indirizzi:
Natl Polytech Inst, Dept Pharm, Natl Sch Biol Sci, Natl Polytech Inst, Mexico City 11340, DF, Mexico Natl Polytech Inst Mexico City DF Mexico 11340 ico City 11340, DF, Mexico
Titolo Testata:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
fascicolo: 1-2, volume: 216, anno: 2001,
pagine: 115 - 125
SICI:
0378-5173(20010323)216:1-2<115:IOACOR>2.0.ZU;2-R
Fonte:
ISI
Lingua:
ENG
Soggetto:
ZERO-ORDER RELEASE; WEAKLY BASIC DRUGS; HYDROXYPROPYLMETHYLCELLULOSE MATRICES; PROPRANOLOL HYDROCHLORIDE; FORMULATION VARIABLES; HYDROPHILIC MATRICES; KINETICS; SYSTEM;
Keywords:
4-aminopyridine; matrix tablets; release mechanism; polymer mixtures; hydroxypropyl; methylcellulose; carboxymethylcellulose;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
25
Recensione:
Indirizzi per estratti:
Indirizzo: Villafuerte, L Natl Polytech Inst, Dept Pharm, Natl Sch Biol Sci, Natl Polytech Inst, Carpio & Plan de Ayala,Col Santo Tomas, Mexico City 11340, DF, Mexico Natl Polytech Inst Carpio & Plan de Ayala,Col Santo Tomas Mexico City DF Mexico 11340
Citazione:
H. Juarez et al., "Influence of admixed carboxymethylcellulose on release of 4-aminopyridine from hydroxypropyl methylcellulose matrix tablets", INT J PHARM, 216(1-2), 2001, pp. 115-125

Abstract

Among different technological variables that influence drug release from hydrophilic matrices, the use of mixtures of polymers represents a potentialway of achieving a variety of release properties. Tablets of the model drug 4-aminopyridine with hydroxypropyl methylcellulose were prepared with different proportions of polymer content as well as with different proportionsof admired carboxymethylcellulose (CMC) in the range up to 35% (based on the total polymer content). The matrices release behavior was examined by absorption of samples at 261 nm (USP 23 apparatus 2, paddle, at 50 rpm) using0.1 N HCl and 0.2 M phosphate buffer as dissolution media. Increasing proportions of CMC in the polymer mixture lead to decreasing dissolution rates,in a range of k = 0.094-0.036 for HCl and k=0.044-0.009 for phosphate buffer. The release mechanism in HCl is predominantly controlled by diffusion (n = 0.46-0.62). while in phosphate buffer it is controlled, as reported previously, by diffusion/relaxation (n = 0.58-0.85) and near zero order release at high CMC concentrations. Approximately doubling the total polymer content gives lower release rates for HCl in the range k = 0.038-0.015 and for phosphate buffer Ii = 0.0099-0.0034. Near zero order release is observed only at pH 7.4 (n = 0.79-0.96). Decreasing release constant values show a logarithmic relationship with increasing values of the exponent II. This indicates that zero-order release occurs with sufficiently reduced release rate. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 11/07/20 alle ore 17:17:42