DETERMINATION OF PLASTICIZERS COMMONLY USED IN PHARMACEUTICAL DOSAGE FORMS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A simple reversed-phase HPLC method was developed to identify and quantify plasticizers commonly used with polymers present in sustained or controlled release dosage forms. The plasticizers investigated included triethyl citrate, tributyl citrate, acetyl triethyl citrate, dibutyl sebacate, diethyl phthalate, dibutyl phthalate, and triacetin. The plasticizers were detected at 220 nm, the mobile phase being methanol:water (70:30 v/v%). The peak area response was linear over the studied concentration range of 0.5-5.0 mM/L for triethyl citrate, acetyl triethyl citrate, dibutyl sebacate, and triacetin, and 0.005 - 0.05 mM/L for diethyl phthalate. The recovery from solvent-cast ethyl cellulose and Eudragit RS 100 films was complete. Two pharmaceutical applications of this assay included the quantitation of plasticizers in polymer-coated sugar beads and a leaching study of a water-soluble plasticizer, triethyl citrate, from polymeric films into simulated intestinal fluids.