L. Whitehead et al., FLOATING DOSAGE FORMS - AN IN-VIVO STUDY DEMONSTRATING PROLONGED GASTRIC RETENTION, Journal of controlled release, 55(1), 1998, pp. 3-12
Gastroretentive dosage forms have potential for use as controlled-rele
ase drug delivery systems. The use of floating dosage forms (FDFs) is
one method to achieve prolonged gastric residence times (GRTs), provid
ing opportunity for both local and systemic drug action. Multiple-unit
systems avoid the 'all-or-nothing' gastric emptying nature of single-
unit systems. A freeze-dried calcium alginate multiple-unit FDF has be
en developed which demonstrated favourable in vitro floating character
istics. The aim of this study was to investigate the in vivo behaviour
of this system compared to a multiple-unit non-floating dosage form m
anufactured from identical material. The study was performed in seven
healthy volunteers, who swallowed the radiolabelled formulations after
a standard breakfast. Transit was monitored by gamma-scintigraphy and
subjects were maintained in the fed state. Prolonged GRTs of over 5.5
h were achieved in all subjects for the floating formulations, which
remained high up in the stomach for the whole of the test period. In c
ontrast, the non-floating beads displayed short GRTs, with a mean onse
t emptying time of 1 h. The results of this study suggest that, in the
fed state, this FDF has potential for sustained drug delivery for eit
her local or systemic purposes. (C) 1998 Elsevier Science B.V.