Experimental investigation of technological parameters of herbal drugs for the extraction and distillation process

The parameters of herbal drugs that are important for technological processes, especially for extraction and distillation processes were examined: bulk density, tapped density, compressibility index, Hausner ratio, and solvent absorption power. The methods described in the pharmacopoeia were used for the examination. Based on the values of bulk density and tapped density, the volume of the device is planned, ie. the size of the batch for extraction or distillation. These parameters were shown to have lower values for flower, leaf and herb, and higher values for fruit and root. Also, the compressibility index depends on the degree of fragmentation and the Hausner ratio. The results showed that these parameters have lower values for fruit and root. Solvent absorption power is the volume of solvent absorbed by a certain amount of herbal drug. Two solvents with differences in concentration were used: ethanol (aqueous solution: 96 vol.%, 70 vol.% and 50 vol.%) and distilled water. At the end of the technological process, a part of the solvent/ extract can be extracted from the spent plant material by pressing or vacuum filtration. The other part is difficult to get rid of the spent plant material and is irreversibly thrown away. In all tested herbal drugs, it is noticeable that the solvent absorption power increases with the increasing polarity of the solvent. Also, the less polar solvent EtOH 96% is more selective in terms of plant part. As the polarity of the solvent increases, it does not matter which part of the plant is extracted.