Previous methods of microencapsulation are unable to process particles smal
ler than 100 mu m without organic solvents or the use of multistep processe
s. The present study investigates the feasiblity of a one-step spray-drying
process to microencapsulate erythromycin and clarithromycin, antibiotics k
nown to have an unpleasant, bitter taste. Mixtures of clarithromycin (5% by
weight) or erythromycin (30% by weight) with a biodegradable polymer were
prepared and spray-dried under specific conditions of temperature and turbi
ne speed. This process resulted in the microencapsulation of 80% of each dr
ug as determined by high pressure liquid chromatography. Particle size rang
ed from 1 to 80 mu m as determined by electron microscopy. These data show
that microencapsulation of macrolides using a spray-drying technique is fea
sible. Spray-drying microencapsulation might be useful in the formulation o
f palatable oral suspensions of bitter tasting drugs.