Low-Substituted Hydroxypropyl Cellulose
»Low-Substituted Hydroxypropyl Cellulose is a low-substituted hydroxypropyl ether of cellulose.When dried at 105for 1hour,it contains not less than 5.0percent and not more than 16.0percent of hydroxypropoxy groups (-OCH2CHOHCH3).
Packaging and storage— Preserve in tight containers.
Identification—
A: Shake about 20mg with 2mLof water and cautiously add 1mLof a solution of anthrone in sulfuric acid (350µg per mL):a blue to greenish blue color develops at the zone of contact.
B: Shake thoroughly 0.1g with 10mLof water.Add 1g of sodium hydroxide,and shake until it becomes homogeneous.Save 5mLof this solution for Identificationtest C.To 0.1mLof this solution add 9mLof 32Nsulfuric acid,and shake.Heat in a water bath for 3minutes,accurately timed,and immediately cool in an ice bath.While the mixture is cold,carefully add 0.6mLof ninhydrin TS,and mix.Allow to stand at room temperature:the red color that appears immediately turns to violet within 100minutes.
C: Shake 5mLof the solution prepared for Identificationtest Bwith 10mLof a mixture of acetone and methanol (4:1):a white,flocculent precipitate is formed.
Loss on drying á731ñ— Dry it at 105for 1hour:it loses not more than 5.0%of its weight.
Residue on ignition á281ñ: not more than 0.5%.
Chloride á221ñ— Shake thoroughly 0.50g with 30mLof boiling water,heat on a water bath for 10minutes,and filter the supernatant by decantation while hot.Wash the residue thoroughly with 50mLof boiling water,combine the washings with the filtrate,and add water to make 100mLafter cooling:a 10-mLportion of this solution shows no more chloride than is contained in 0.25mLof 0.02Nhydrochloric acid (0.36%).
Assay— Proceed as directed for the determination of hydroxypropoxy in the Assayunder Hypromellose 2906,except to substitute Low-Substituted Hydroxypropyl Cellulose for Hypromellose 2906throughout.[NOTE—Since methoxy is not determined,the addition of methyl iodide is not needed.]
Auxiliary Information— Staff Liaison:Justin Lane,B.S.,Scientific Associate
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3019
Pharmacopeial Forum:Volume No.30(1)Page 338
Phone Number:1-301-816-8323