Page 324 - Pharmacognosy 2 PG303

Pharmacognosy-2 (PG303) Level 2 Clinical Pharmacy-Pharm D

Preparation
The oleoresin from which colophony is obtained is largely a pathological
product formed in the wood of the Pinus trees due to the stimulation of the cambium
through injury, to form new wood containing large numbers of oleoresin reservoirs.
The oleo-resin is obtained commercially from the trees by several methods. One of
these methods, is known as the cup and gutter method. It consists of cutting a series
of downward and inward sloping V-shaped incisions into the trunk of the tree for a
distance of about a foot. This is usually done early in the year. At the base of these
incisions, an aluminium or earthenware cup is affixed to the trunk and two
aluminium strips (aprons) are inserted above to deflect the flow of the oleo-resin into
the cup. The oleo-resin soon begins to run and collects in the cup. As the cups
become filled, they are emptied into wooden barrels and others affixed to the tree.
In about a week or ten days, the flow of oleo-resin diminishes and another series of
incisions started above the first excavation. Production continues until autumn.

The crude turpentine is then transferred to the turpentine stills, which are of
copper, and are set in brick furnaces. Water is added and the whole warmed, any
chips of wood and other debris that float to the top being skimmed off, and the heat
is then increased. At first water and oil of turpentine distil over, subsequently oil of
turpentine alone. Water is occasionally added to prevent the resin from charring.
After the distillation has been stopped the melted resin is run through wire strainers
into barrels and allowed to solidify.

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