Carbohydrate polymeric blend microspheres of sodium
alginate and methylcellulose were prepared and characterized
by differential scanning calorimetry, scanning electron
microscopy, and particle size distribution. DSC
thermograms have confirmed the uniform molecular distribution
of the drug molecules in the microspheres.
SEM micrographs exhibited a spherical morphology of
the prepared microspheres. The drug was released in a
controlled manner. The swelling studies of microspheres
have shown that with an increasing amount of MC in
the microspheres, water uptake has decreased. This effect
is correlated with the release rates of the drug though
the microspheres containing different amount of MC.
The microspheres have shown lower densities and hence,
these could be retained in the gastric environment for
more than 12 h, which would help to improve the
bioavailability of nifedipine.