Tablet and capsule formulations incorporating high doses of a dry optimized herbal extract: The case of Satureja kitaibelii

Here at Gamlen we are highlighting some of the fascinating and ground-breaking research that has been carried out by our customers in our Paper of the Month posts.

In Gamlen’s March paper of the month the authors describe how they successfully developed capsule and direct compression tablet formulations containing a high percentage of an herbal extract. They achieved this with the aid of a Gamlen Powder Compaction Analyser.

  • The herb of Satureja kitaibelii contains several bioactive compounds and has been found to have multiple medicinal uses.
  • A dry extract Satureja kitaibelii was produced using a heat-assisted method.
  • The Gamlen data showed that compacting a blend of the herbal extract with 1% magnesium stearate did not produce tablets of sufficient tablet tensile fracture strength.
  • Addition of sodium starch glycolate to this formulation improved the strength of the tablets to an acceptable level and reduced disintegration time.
  • A capsule formulation where the herbal extract represented 99% of the formulation was also prepared.


A capsule and direct compression tablet formulation, respectively containing 99 and 95% of the herbal extract, were successfully developed with acceptable properties.