Historically, a tincture of cannabis indica was used to treat patients with acute and chronic bronchitis with good results. Keyword: "bronchitis" and "cannabis" in Google Books for a time period between 1850 and 1900. You will discover hundreds of articles published on the subject in medical journals. You should be able to find recipes, dosage amounts, when and how often to take, etc. along with doctors' case studies.

A tincture of cannabis is awful tasting stuff. Remember: "a teaspoon of sugar makes the medicine go down," comes from this same time period. I would suggest any other method of ingesting a concentrate of cannabis over a tincture.

All that said, I'm unsure if you are attempting an alternative treatment for bronchitis, or if you're just missing the euphoric effects of puffing cannabis. Of course, if this historical treatment doesn't result in positive improvements, it should at least give you good euphoric experience.