Extraction by solvent

The ability of water and other solvents to extract the drug from the intact and manipulated tablets was evaluated. Table 2 provides a list of solvents that have been evaluated. The selection of the solvent is based on ease of availability and physicochemical properties of the solvent (e.g. acid/base, organic/aqueous, etc.). Similar to water, both Level 1 and Level 2 solvents are generally easily accessible in the household, with Level 1 solvents being more accessible than Level 2 solvents. For short term extraction studies, one test tablet or manipulated product (equivalent to one intact tablet) was transferred to a 100 mL beaker and 100 mL of selected solvents were added. Samples were withdrawn at 5, 15, 30, and 60 min to determine the amount of drug extracted. All samples were diluted 10 times (e.g. 100 μL diluted to 1 mL) before HPLC analysis. Effect of heat on the extraction was evaluated by repeating the study at elevated temperature. For aqueous solvent, the temperature was maintained at boiling condition of water (i.e. 100°C). For aqueous-alcohol solvents, water-bath temperature of 60°C was maintained. Due to safety concern, heat studies on strong acid/base and acetone were not conducted in this study. Effect of long term extraction was studied by soaking the products in the extraction solvents for overnight duration (20 h).

Solvent selection for extraction study