Because of its use in the pharmaceutical and food industries, the USP has established standards relating to the amount of methoxyl and 2-hydroxypropoxyl substitutions in hypromellose. The USP implements a gas chromatography (GC) method for the determination of the ether content. Here we describe the validation of an assay using an Ultra Performance Liquid Chromatography (UPLC) method for the simultaneous analysis of the methoxy and 2-hydroxypropoxy content of hypromellose that improves assay precision while decreasing inputs and cost.
