Bioassay standardization of drug dosage form prepared from hydroalcoholic extract of Dracocephalum kotschyi

Zaringiah (Dracocephalum kotschyi) is a famous Iranian herbal plant with anti-inflammatory and spasmolytic activities. There is no standard drug dosage form for the D. kotschyi extract on the market. The objective of this project was to design a suitable oral dosage form for the hydroalcoholic extract of D. kotschyi.

Standard granules were prepared using the moist granulation technique. Physical properties of the granules were determined before filling the capsule with fixed doses of the drug (25 mg and 50 mg). Syrup was prepared in sucrose solution at 5 mg/mL concentration. Bioactivity and phytochemical assays were used for dosage form stability and uniformity evaluations before and after 3- and 6- months incubation. Pharmacological bioassay method was designed to determine the bioactivity of the products before and after incubation. Pharmacological effects of the prepared capsule and syrup were determined on rat isolated ileum and intestinal meal transit, respectively.

In this study, D. kotschyi extract was effectively formulated as capsule and syrup for oral consumption. Environmental and aging factors had no significant effect on the total flavonoid or phenolic contents or bioactivity of the manufactured products. Furthermore, the ingredients used in the formulation had no effect on the bioactivity of the active substances in the extract.

The standard oral dosage forms prepared from D. kotschyi extract can be used for clinical trials. In addition, we introduced a reliable bioassay technique, which might be applied for the evaluation of herbal medicines with antispasmodic activities.