Bacteriophage formulated into a range of semisolid and solid dosage forms maintain lytic capacity against isolated cutaneous and opportunistic oral bacteria

BACKGROUND: Resistance of bacteria to antimicrobial agents is of grave concern. Further research into the development of bacteriophage as therapeutic agents against bacterial infections may help alleviate this problem. OBJECTIVES: To formulate bacteriophage into a range of semisolid and solid dosage forms and investigate the capacity of these preparations to kill bacteria under laboratory conditions. METHODS: Bacteriophage suspensions were incorporated into dosage forms such as creams, ointments, pastes, pessaries and troches. These were applied to bacterial lawns in order to ascertain lytic capacity. Stability of these formulations containing phage was tested under various storage conditions. KEY FINDINGS: A range of creams and ointments were able to support phage lytic activity against Propionibacterium acnes. Assessment of the stability of these formulations showed that storage at 4 °C in light-protected containers resulted in optimal phage viability after 90 days. Pessaries/suppositories and troches were able to support phage lytic activity against Rhodococcus equi. CONCLUSIONS: We report here the in-vitro testing of semisolid and solid formulations of bacteriophage lytic against a range of bacteria known to contribute to infections of the epithelia. This study provides a basis for the future formulation of diverse phage against a range of bacteria that infect epithelial tissues.