Matrix release from tablets prepared with aqueous
dispersion of an acrylate methacrylate (a water –
insoluble) copolymer as binder
Florence E. Eichie*, Roland S. Okor,
Omameri Esi
Department of Pharmaceutics and Pharmaceutical
Technology,
University of Benin, Benin City, Nigeria
*For
Correspondence:
Tel: +234-803-634-7181
E-mail:
eichiefe@yahoo.com
International Journal of Health Research,
December
2008; 1(4):
235-240 (e143p18-24)
Received:
16-Sep-08
Revised: 30-Dec-08 Accepted:
31-Dec-08
Original
Research Article
Abstract
PURPOSE:
To investigate the binder effect of aqueous dispersions
of acrylate methacrylates (AMA) copolymer with a view to
obtaining matrix (non-disintegrating) tablets with a
retard release property.
METHODS:
Aqueous
dispersions of AMA (1-15% w/v) were formed by a
coacervation procedure using ethanol (10 ml) as solvent
and water (90 ml) as non-solvent for the copolymer. The
aqueous dispersions were used to wet–mass the drug (paracetamol)
powder. Resulting granules were compressed to 500 mg
tablets using a single punch machine. The tablets were
subjected to hardness, friability, disintegration and
dissolution tests.
RESULTS:
The granules formed hard tablets (tensile strength 1
- 2.0 MNm-2) with low friability decreasing
from 2 to 1 % as the AMA binder concentration increased
from 0.75 to 11.25% w/w. The tablets failed to
disintegrate in 3 hr. Drug release generally followed
the Higuchi square root of time kinetic (R2 ≥
0.95). The AMA binder markedly retarded drug release as
reflected by the sharp decrease in the dissolution rate
constant from 30 min–2
(AMA, 0.75% w/w) to 9 min–2
(AMA, 11.25% w/w).
CONCLUSION:
The AMA
dispersion is an effective binder, producing matrix
tablets with a retard release property controlled by the
binder content in the tablets.
Keywords:
Acrylate methacrylate copolymer; Aqueous dispersions;
Matrix tablets, Retard release; Friability index;
Tensile strength.
