This document provides information about different extraction techniques used in pharmaceutical science. It discusses solid-liquid extraction techniques including maceration, decoction, percolation, and hot continuous extraction using a Soxhlet apparatus. Maceration involves soaking plant material in solvent to extract soluble compounds. Decoction involves boiling plant material in water to extract heat-stable, water-soluble compounds. Percolation uses powdered plant material packed in a column with solvent percolated through. Soxhlet extraction uses a continuous extraction process with a solvent vapor condensing and extracting compounds from plant material in a thimble.