B:
Dissolve 50 mg, accurately weighed, in water to make 250.0 mL, and mix. Pipet 10 mL of this solution into a 100-mL volumetric flask, add 2 mL of 10 percent, pH 6.0 phosphate buffer (see
Buffer Solutions in the section
Reagents, Indicators, and Solutions), add water to volume, and mix: the UV absorption spectrum of the solution exhibits maxima and minima at the same wavelengths as that of a similar solution of
USP Proparacaine Hydrochloride RS, concomitantly measured, and the respective absorptivities, calculated on the dried basis, at the wavelength of maximum absorbance at about 310 nm do not differ by more than 3.0%.
C:
A solution (1 in 50) responds to the tests for
Chloride 
191
, the procedure for alkaloidal hydrochlorides being used.
;)
and 185