EFFECT OF POTASSIUM CARBONATE AND VISCOSITY GRADE OF HYDROXYPROPYLMETHYLCELLULOSE ON THE BIOAVAILABILITY OF FUROSEMIDE FROM PRESS-COATED PROLONGED-RELEASE TABLETS
T. Sirkia et al., EFFECT OF POTASSIUM CARBONATE AND VISCOSITY GRADE OF HYDROXYPROPYLMETHYLCELLULOSE ON THE BIOAVAILABILITY OF FUROSEMIDE FROM PRESS-COATED PROLONGED-RELEASE TABLETS, STP pharma sciences, 4(4), 1994, pp. 257-263
This study concerns press-coated modified-release tablets in which bot
h the core and the coat contain a drug (furosemide) but only the coat
contains a polymer (hydroxypropylmethylcellulose) to control drug rele
ase. The drug release profile from this kind of tablet is biphasic: a
slower initial phase is followed by a clear increase in the release ra
te. The main aim was to study the scope for systematic modification of
the release rate of furosemide using the alkalizing agent, potassium
carbonate. It is concluded that the addition of potassium carbonate is
necessary for adequate release and absorption of furosemide from the
press-coated tablets described. The optimum amount of potassium carbon
ate was that chemically equivalent to the amount of furosemide in the
tablet. This conclusion is based on in vitro dissolution studies and o
n bioavailability studies in dogs. The polymer in the coat also affect
ed the drug release profile and absorption parameters.