Dear All

Is there anyone using WHO specified method for Ethambutol HCL Tablets for Assay? Are u facing any problem with it?

http://www.who.int/entity/medicines/pub ... b_mono.pdf

We are using the method specified for INH, PYRA and Ethambutol for the determination of Ethambutol content only. For INH, PYRA and Rifampin we are using another method.

While using this method for Ethambutol content we are getting a peak in standard preparation which is close to the main peak (resolution 1.5), which is sometime merging with main peak?

Regards