Colloidal Oatmeal
»Colloidal Oatmeal is the powder resulting from the grinding and further processing of whole oat grain meeting U.S.Standards for Number 1or Number 2oats (7CFR810.1001).
Packaging and storage—
Preserve in well-closed containers.
Identification—
A:
Prepare a smooth mixture of 10g of Colloidal Oatmeal and 100mLof warm water.After stirring for 10minutes,the resulting slurry has a characteristic slippery feel and shows the development of slimy,viscous strands.
B:
Awater slurry is colored reddish violet to deep blue by iodine TS.
Viscosity á911ñ—
Sample preparation—
Transfer 25g of Colloidal Oatmeal in small portions,with stirring at 1000rpm over a 1minute period,to 500mLof water contained in a beaker,maintained at 45
and equipped with a variable speed mixer.Stir for 5minutes after the addition of the last portion of oatmeal.Allow the suspension to stand for 90minutes,and equilibrate to ambient temperature.Stir the suspension at 800rpm for 1minute.
and equipped with a variable speed mixer.Stir for 5minutes after the addition of the last portion of oatmeal.Allow the suspension to stand for 90minutes,and equilibrate to ambient temperature.Stir the suspension at 800rpm for 1minute.
Apparatus—
Equip a suitable rotational viscosimeter with a spindle having a cylinder 1.88cm in diameter and 6.25cm high attached to a shaft 0.32cm in diameter,the distance from the top of the cylinder to the lower tip of the shaft being 0.75cm,and the immersion depth being 8.15cm (No.1spindle).
Procedure—
Determine and record the viscosity of the suspension,with the spindle rotating at 60rpm.Convert to centipoise by multiplying the reading by the constant for the viscosimeter spindle and speed employed.The average of three viscosities obtained is greater than 1and less than 100centipoises.
Microbial limits á61ñ—
The total aerobic microbial count does not exceed 10,000cfu per g.The total combined molds and yeasts count does not exceed 150cfu per g.
Loss on drying á731ñ—
Dry it at 120for 4hours;it loses not more than 10%of its weight.
for 4hours;it loses not more than 10%of its weight.
Particle size á786ñ:
not more than 3%of the total particles exceed 150µm in size and not more than 20%of the total particles exceed 75µm in size.
Total ash á561ñ:
not more than 2.5%,calculated on the dried basis.
Fat content—
Dry about 4g,accurately weighed,in vacuum at 100for about 5hours.Extract the fat from it with the anhydrous ethyl ether,using a continuous extraction apparatus,the extraction period being about 4hours at a condensation rate of 5to 6drops per second.Evaporate the ether from the extract,transfer it to a tared beaker,and dry at 100to constant weight.Perform a blank determination.The percentage of fat found,corrected for the blank,is not less than 0.2%.
for about 5hours.Extract the fat from it with the anhydrous ethyl ether,using a continuous extraction apparatus,the extraction period being about 4hours at a condensation rate of 5to 6drops per second.Evaporate the ether from the extract,transfer it to a tared beaker,and dry at 100to constant weight.Perform a blank determination.The percentage of fat found,corrected for the blank,is not less than 0.2%.
Nitrogen content,Method Iá461ñ:
not less than 2.0%.
Auxiliary Information—
Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(PA6)Pharmaceutical Analysis 6
USP28–NF23Page 543
Phone Number:1-301-816-8389