A modified dissolution rate equation was used to quantitatively investigate
the contribution of simple bile salt (BS) micelles and mixed B S-lecithin
(L) micelles to a cholesterol monohydrate (ChM) dissolution. Using a least-
squares technique to assess the relationship between the ChM dissolution ra
te and BS concentration at a constant , concentration, good curve-fittings
were obtained when the BS monomer concentration was set to equal the critic
al micellar concentration (CMC). For taurochenodeoxycholate (TCDC), a dihyd
roxy BS, the resulting values of parameters show that the simple TCDC micel
le rate constant (ks) increases, but the mixed TCDC-L micelle rate constant
(kM) decreases with increasing L concentrations. As for taurocholate (TC),
a trihydroxy BS, a ChM dissolution study was conducted over the initial 2
hour period in different TC-L solutions. A similar curve-fitting analysis r
evealed that the simple TC micelle ks is independent oft concentration and
is much higher than the kM of mixed TC-L micelles. Moreover, the outcome of
the analysis supports previously reported equilibrium dialysis study resul
ts concerning the BS to L ratio of mixed BS-L micelles. According to the co
llision theory, the resulting kS and kM values are interpreted.