I Was Recently Prescribed A Low Dose Of Hydrochlorithiazide. A

I was recently prescribed a low dose of hydrochlorithiazide. A few weeks ago, I read on the internet that this drug was made with a substance called valsartran, by some manufacturers. Valsartran was found to be carcinogenic. My question is how do I know which drug manufacturer of hyrdrocloritiazide is not using valsartran to manufacture this drug. That would be the drug i want to purchase.
Barb Gross