Study on the stability of rifampicin solution

Objective To study the appropriate pH for rifampicin solution and choose the optimal formulation of rifampicin solution. Methods According to the factors that affect the stability of rifampicin solution, pH and antioxidant were studied. The physical stability was studied using accelerated experiment.Results The appropriate pH of rifampicin solution was 6.0-7.0. The optimum formulation was consisted of rifampicin 1.2 g, sodium formaldehyde sulfoxylate 0.3 g, sodium ascorbate 0.3 g, sodium citrate 0.079 g,lysine 0.10 g, propylene glycol 15 mL, adding purified water to 1 000 mL. Conclusions pH and the antioxidants are the main factors affected stability of rifampicin solution.