Page 344 - Pharmacognosy 2 PG303

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

Balsam of Peru is the balsam exuded from the beaten and scorched trunk of
Myroxylon Pereirae (Royle) Klotzach (Fam. Leguminosae-Papillionoideae).
Balsam of Peru contains not less than 50 % and not more than 70 % w/w of balsamic
esters which have a saponification value of not less than 230.

The balsam trees attain about 25 metres in height. They are abundant along
the coast of San Salvador in Central America and are cultivated in Florida and
Ceylon.

Preparation
The balsam is a pathological product and is formed by injury to the trees. The
tree is beaten on four sides and scorched with a torch to cause the bark to separate
from the trunk. Four intermediate strips being left uninjured so as not to kill the tree.
Within a week, the bark drops from the trunk and the balsam begins to exude freely
from the exposed wood. The areas are then wrapped with rags which are removed
from time to time when they become saturated with balsam; then they are boiled
with water and as the water cools, the balsam settles out is recovered, strained, and
packed, usually in tin cans.

Description
Balsam of Peru is a dark brown, viscous liquid; appearing dark reddish-brown
and transparent in thin layers; free from stickiness or stringiness; odor, agreeable,
balsamic and vanilla-like; taste, slightly bitter, producing a burning sensation when
swallowed. Balsam of Peru does not harden on exposure to air.

Solubility
Balsam of Peru is practically insoluble in water; soluble in absolute alcohol
and in an equal volume of alcohol 90 % but on the further addition of two or more
volumes of alcohol 90 % the solution becomes turbid; soluble also in chloroform
and in glacial acetic acid with not more than an opalescence; partially soluble in
ether, in petroleum ether, in benzene and in carbon disulphide. It does not mix with
fixed oils.

Tests for Identity
1- Specific gravity, 1.150-1.170; acid value, 56-84.
2- Shake about 0.5 g of Balsam of Peru with 100 ml of water; the aqueous solution
is acid to litmus paper.
3- Shake 1 g of Balsam of Peru with 15 ml of petroleum ether in a test tube; the
balsam partially dissolves, the non-dissolved portion clings to the walls of the
tube as a sticky mass, and no insoluble powder sinks to the bottom; filter and
evaporate 6 ml of the filtrate in a small porcelain dish, on a water bath; the residue
has no odour of benzaldehyde or of turpentine (c.f. Benzaldehyde or Turpentine).

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