Use of microparticles combined with submicron oil-in-water emulsions

DETAILED DESCRIPTION OF THE INVENTION The practice of the present invention will employ, unless otherwise indicated, conventional methods of chemistry, biochemistry, molecular biology, immunology and pharmacology, within the skill of the art.
Such techniques are explained fully in the literature.
See, e.
g.
, Remington's Pharmaceutical Sciences, 18th Edition (Easton, Pa.
: Mack Publishing Company, 1990); Methods In Enzymology (S.
Colowick and N.
Kaplan, eds.
, Academic Press, Inc.
); and Handbook of Experimental Immunology, Vols.
I-IV (D.
M.
Weir and C.
C.
Blackwell, eds.
, 1986, Blackwell Scientific Publications); and Sambrook, et al.
, Molecular Cloning: A Laboratory Manual (2nd Edition, 1989).
All publications, patents and patent applications cited herein, whether supra or infra, are hereby incorporated by reference in their entirety.
As used in this specification and the appended claims, the singular forms "a," "an" and "the" include plural references unless the content clearly dictates otherwise.
I.
Definitions In describing the present invention, the following terms will be employed, and are intended to be defined as indicated below.
The term "microparticle" as used herein, refers to a particle of about 100 nm to about 150 .
mu.
m in diameter, more preferably about 200 nm to about 30 .
mu.
m in diameter, and most preferably about 500 nm to about 10 .
mu.
m in diameter.
Preferably, the microparticle will be of a diameter that permits parenteral administration without occluding needles and capillaries.
Microparticle size is readily determined by techniques well known in the art, such as photon correlation spectroscopy, laser diffractometry and/or scanning electron microscopy.
Microparticles for use herein will be formed from materials that are sterilizable, non-toxic and biodegradable.
Such materials include, without limitation, poly(.
alpha.
-hydroxy acid), polyhydroxybutyric acid, polycaprolactone, polyorthoester, polyanhydride.
Preferably, microparticles for use with the present invention are derived from a poly(