Hi, @Diego_HM.
Thank you for sharing the information. And I add the information of the excipients of these products.
The inactive ingredients contained in Inderal LA capsules are: cellulose, ethylcellulose, gelatin capsules, hypromellose, and titanium dioxide. In addition, Inderal LA 60 mg, 80 mg, and 120 mg capsules contain D&C Red No. 28 and FD&C Blue No. 1; Inderal LA 160 mg capsules contain FD&C Blue No. 1.
As we discussed in the lactose topic, excipients from natural origins have the risk of nitrite contamination at a trace amount. The pKa of this product is about 9.5, and as you pointed out, propranolol hydrochloride is acidic in solution. We should assess this product carefully.