Formation of a molecular compound between berberine hydrochloride and sulfa drugs was examined by thermal analysis using sulfanilamide, free homosulfaniiamide, sulfathiazole, sulfaguanidine, sulfadiazine, sulfamerazine, and sulfisoxazole. It was found that berberine hydrochloride formed molecular compound in 1:1 molar ratio with sulfanilamide and sulfaguanidine. The fact was further confirmed from elemental analysis and infrared absorption spectrum.
