More MS news articles for August 2002

Preparation of 3,4-diaminopyridine microparticles by solvent-evaporation methods

Int J Pharm 2002 Aug 21;242(1-2):197
Gibaud S, Bonneville A, Astier A.
Laboratoire de Pharmacie Clinique, UPRES EA 2399, Faculte de Pharmacie, 5, rue Albert Lebrun, 54000, Nancy, France

The present study compares two methods of preparation of microparticles of 3,4-diaminopyridine (3,4-DAP) for the treatment for multiple sclerosis and Lambert-Eaton myasthenia syndrome.

Poly( varepsilon -caprolactone) microparticles were prepared with a solvent-evaporation W/O method.

The 3,4-DAP was dispersed in dichloromethane, leading to a suspension.

The dispersion and the solidification of the dichloromethane droplets in an aqueous phase have led to microparticles of 55.3+/-34.7 &mgr;m.

The incorporation of the drug by milligram of powder was very low (1.91 &mgr;g/mg) and the scanning electron microscopy (SEM) did not show any crystal but marks of dissolved crystals were observed on the polymeric surface.

Eudragit((R))RS microspheres containing 3,4-DAP were prepared by a solvent-evaporation technique using light mineral oil as continuous phase.

The drug and the polymer were completely dissolved in an acetone solution, used as discontinuous phase.

This formulation have led to a higher incorporation of the drug (88.25 &mgr;g/mg).

The particle size was 91.8+/-44.3 &mgr;m.

The observation, by SEM, shows many crystals on the surface and inside the microparticles.

A slow-release of the drug in a phosphate buffer pH 7.4 was observed (50% in 60 min and about 70% in 4 h).