- Alcohol or alcoholic precipitate acacia in the form of a viscid mass, when the alcohol amounts to more than about 50 percent of the total volume. Solution is effected by dilution with water.
- The mucilage is gelatinized by ferric chloride solution and tincture, ferric sulfate, ferric subsulfate and iron and ammonium acetate solutions, but not by ferric citro-chloride tincture or the scale salts of iron. This gelatination is prevented by alkali acetates, cintrates and tartrates and by dilution with water, glycerin or syrup.
- Concentrated solutions of borax and lead acetate solution also gelatinized acacia, but is retarded by adding syrup or glycerin.
- Acacia contains calcium and therefore possess the incompatibilities of this iron.
- Acacia contains a peroxidase which act as an oxidizing agent and produces colored derivatives of aminopyrine, antipyrine, cresol, guaiacol, phenol, tannin, thymol, vanillin and other substances. Heating the solution of acacia for a few minutes at 100oC destroys the peroxidase and the color reactions are avoided.
- Sulfuric acid converts acacia into arabic and then metarabic acid and precipitate calcium sulfate.
Illustration of
Acacia Incompatibilities and their Criticisms
No. 1
Rx
Tincutre guiaici
/
aa ............................... 1 fluidram
Muc. Acaciae /
M. S. Teaspoonful
every three hours.
Criticisms: The
alcohol of the tincture throws the acacia out of solution and the
water of the mucilage precipitate the resin from the tincture so that
a white precipitate ultimately forms in the bottom of the bottle. A
fresh tincture of guaiac with mucilage of acacia gives a blue color
but and old tincture gives a brown-red color. With the consent of the
physician the prescription may be filled by using glycerin and water
instead of mucilage. Or honey in place of the mucilage keeps the
resinous matter better suspended than glycerin.
No. 2
Rx
Liquoris ferri
dialysati ...................... iv foz
Syrupi
................................................i fluidram
Mucilainis
acaciae .............................iv fluidrams
M.
Criticisms:
Ferric salts gelatinized mucilage of acacia, and if the solution of
dialyzed iron is added directly to the mucilage a solid mass results,
which dissolves slowly in the syrup. By diluting the solution of iron
with syrup, and then adding this slowly to the mucilage with constant
stirring, a thick homogenous liquid may be obtained.
No. 3
Rx
Liq. Plumbi
subacat ...............................foz ss
Muc. Acaciae
.........................................i fluidram
Aq. ditil., q.s.
ad. ...................................iv fluidrams
M. Ft. lotio
Criticisms: When
solution of lead subacetate is added to mucilage of acacia, a solid
gelatinous mass is formed. In this prescription if both are diluted
with water and mixed with constant stirring the acacia is
precipitated in small masses. Neutral lead acetate solution does not
gelatinize mucilage of acacia. The addition of a few drops of acetic
acid may also prevent the precipitation of the acacia.
No. 4
Rx
Sodii boratis
....................................ii oz
Pulv. Acaciae
...................................i oz
Syrupi
..............................................fluidram ss
Aq. menthae pip
..............................iii fluidrams
M. S. A.
Sig. A tsp q 3
hours.
Criticisms: There
could be a physical incompatibility between acacia and borax but this
is prevented by the syrup. This is properly dispensed by dissolving
the borax in the aq. mentha. pip. and acacia in the syrup then mix
the two solutions.
