Development of sustained-release polymer matrices of benzathine penicillin for intramuscular injectibles

CHED 1279

Melissa Molyneux, uphereinthetree@yahoo.com1, Marc M. Baum, m.baum@oak-crest.org1, and Thomas J. Smith2. (1) Oak Crest Institute of Science, 2275 E. Foothill Blvd., Pasadena, CA 91107, (2) Auritec Pharmaceuticals, 2275 E. Foothill Blvd., Pasadena, CA 91107
Penicillin G (PG) is the most widely-used antibiotic in the world, and its spectrum of activity against infectious disease is broad. A single sustained-release injectible could save countless lives in developing countries where treatment-compliance is a socioeconomic phenomenon, and in the developed world where chronic prophylaxis is needed. A method for crystallization of benzathine PG in MeOH:H2O solvent systems is reported. Temperature-dependent rapid decomposition of PG in deionized H2O at ambient, 4oC, and -10oC, is studied spectroscopically. Molar absorptivities at 218nm are calculated for benzathine PG, both for analytical and commercial forms. Polymer matrices of commercial benzathine PG formulation encapsulated in polyvinyl alcohol and polylactic acid are manufactured as a prototype sustained-release delivery system and their dissolution profile compared to the uncoated commercial formulation in aqueous solution.