Used primarily to treat bacterial infections, especially those caused by susceptible strains of streptococci and treponemes. It is the preferred treatment for syphilis due to its prolonged release and long duration of action. Also used in the management of streptococcal pharyngitis and to prevent rheumatic fever recurrence. Administered by intramuscular injection, it provides sustained low levels of penicillin in the bloodstream, making it suitable for outpatient treatment where compliance may be a concern.