Clerodendrum inerme, a medical plant widely found in Thailand, has been reported for the use in Thai traditional medicine. The whole plant of C. inerme contains many phenolic compounds, which have documented benefits as antimicrobial, anti-carcinogenic, anti-inflammatory and antioxidant. This research aims to study the suitable condition of phenolic compound extraction from C. inerme. The experiments are divided into two systems: batch extraction and continuous extraction in a packed bed extractor. The suitable conditions for the batch extraction were: 50% (v/v) ethanol solution as solvent, extraction temperature at 75°C, solvent-to-solid ratio of 20:1 (ml/g), particle size of less than 75 µm, extraction time of 240 min, in which the yield of phenolic compounds at 14.48 mg. equivalent gallic acid / g. dry weight was obtained. The suitable conditions in the packed bed were: 50% (v/v) ethanol solution at flow rate of 25 ml/min, extraction temperature 75˚C, particle size of 180-300 µm, and extraction time of 180 min, whereas the yield of phenolic compounds at 14.83 mg. equivalent gallic acid / g. dry weight was obtained. It was found that at the suitable condition, the packed bed extractor had a better performance than that of the batch extraction. The extraction rate of the phenolic compound increased with increasing feed flow rate. At feed flow rate of 25 ml/min, the highest average diffusivity of phenolic compound at 23.6 ×10-13 m2/s was obtained, whereas in the batch extraction, the average diffusivity of phenolic compound was 1.64 ×10-13 m2/s.
