TINCTURAE— TINCTURES 



Tinctures are alcoholic solutions of non-volatile substances ob- 

 tained by the extraction of drugs. Tincture of iodine is an excep- 

 tion to the rule of non-volatile substances, while ioth tincture of 

 iodine and tincture of the chloride of iron are made by solution. 

 They differ from spirits in that, with the exception of tincture of 

 iodine, the substances from which they are prepared are non-vola- 

 tile. They differ from fluidextracts in respect to strength. They 

 are weaker than fluidextracts and noit uniform in strength, except 

 that the potent tinctures are ten per cent, strength of the drug. 

 Tinctures may be prepared by maceration, percolation, and solu- 

 tion or dilution. 



The Pharmacopoeia states that unless otherwise directed in the 

 text, tinctures shall be made by one of two processes — Type P, Per- 

 colation and Type M, Maceration. 



Type Processes for Tinctures 

 Type Process P — Percolation 



Moisten the powdered drug or mixed drugs as designated in 

 the formula with a sufficient quantity of the prescribed menstruum 

 to render it evenly and distinctly damp, transfer it to a percolator, 

 and, without pressing the powder, allow it to stand well covered 

 for six hours; then pack it firmly, unless otherwise directed, and 

 pour on enough of the menstruum to saturate the powder and leave 

 a stratum above it. When the liquid begins to drop from the per- 

 colator, close the lower orifice, and, having closely covered the per- 

 colator, macerate for twenty-four hours. Then allow the percola- 

 tion to proceed slowly, gradually adding sufficient of the men- 

 struum to make one thousand mils of the finished tincture. 



Type Process M — Maceration 



Macerate the drug or mixed drugs designated in the formula 

 in a stoppered container, in a moderately warm place, with seven 

 hundred and fifty mils of the prescribed solvent (unless a differ- 

 ent amount is specified in the formula). Continue the maceration 

 with frequent agitation during three days or until the drug is 

 practically extracted, transfer the mixture to a filter and, when the 

 liquid has drained off completely, gradually wash the residue on 



