Lehyam or Avaleham or Rasayanam or Prasam are semisolid or thickened extracts. Generally lehya preparation are indicated in respiratory ailments, digestive troubles, and for general tonic effect in the body. Administration of lehya favours absorption of active principles from oral cavity onwards.

BASIC COMPONENTS .
Aqueous Medium: Water/Decoction/Expressed Juice
Sugar Medium: Jaggery/Sugar/Sugar Candy/Honey
Solid medium: Fine power of drugs, Pulp of fruits

According to certain formulations addition of Milk, Butter milk, Ghee, Gingerly oil, Coconut juice, etc, are prefered.
Decoction /Expressed Juice, after being strained is again boiled down to a thick soft consistency with sugar medium. Powdered drugs which contain volatile principles are sprinkled at this stage. Honey is added after cooling. The volatile fractions will be protected by the sugar molecules, which act as a preservative for the preparation.

Quality Control Criteria: Loss of weight on drying at 110 C, pH, Reducing /non reducing sugars, total solid content, Sp. Gravity, Fat content.

Organoleptic features: Should sink in water, not readily dissolve in it and should be drawn out into threads. Neither be hard nor thick fluid. Colour and taste depends upon the drugs used. Emits sweet smell.