Effects of different parameters on supercritical fluid extraction of steroid drugs, from spiked matrices and tablets

Feasibility of supercritical CO2 extractions of two steroid drugs, medroxyprogesterone acetate (med) and cyproterone acetate (cyp), were evaluated. The effects of temperature (308–348 K), pressure (100–300 bar), static extraction time (5–15 min), dynamic extraction time (10–30 min) and percent methanol modifier (1–10% v/v) on the SFE recoveries of these drugs from spiked matrices (glass) and pharmaceutical dosages (tablets) were investigated. The results showed that minor structural differences between related compounds might lead to dramatically differences in extraction behaviors under the same conditions. The optimum SFE conditions to extract the drugs from spiked glass were 10 min static, 30 min dynamic, 300 bar, 348 K and 5% modifier in the case of med acetate and 10 min static, 30 min dynamic, 100 bar, 308 K, and 10% modifier in the case of cyp. Under these conditions above 90% of the total recovery was obtained for both drugs. Extractions from pharmaceutical dosages were less efficient compared to glass beads under the same conditions. Quantitative recovery of solutes from tablets were obtained upon changing extraction conditions to: 15 min static, 45 min dynamic, P=300 bar, 20% modifier (for med) and 10% (for cyp).