Application of HPLC to assess the compatibility of bisoprolol fumarate with selected excipients in mixtures by isothermal stress testing.

In the present study, the compatibility between bisoprolol fumarate and selected excipients (ascorbic acid, citric acid anhydrous, butylated hydroxyanisole, polyvinylpyrrolidone, glycerol, mannitol and sorbitol) in mixtures (1:10 ratio of drug and excipient) was investigated by subjecting the samples to isothermal stress conditions (90 °C for 48 h). A new HPLC method was developed, validated and employed for determining the drug content of the stressed compatibility samples. Results of HPLC revealed that major degradation of bisoprolol fumarate was observed with butylated hydroxyanisole (89.4%), citric acid anhydrous (89%), mannitol (77%) and glycerol (61.9%).