Rasomycin-LA has the action and pharmacological behavior similar to Rasomycin-5 and Rasomycin-10 except with long lasting effects, remaining over a period of 3 to 5 days. A controlled release of the active agent takes place at the injection site in the muscle tissue. The released part is immediately made bio-available and causes a rapid rise in blood and tissue levels. The bound part gradually and eventually returns to solution to a solution to provide persistent blood and tissue levels. The quantity of Oxytetracycline absorbed at the injection site behaves in the same manner as short term Oxytetracycline. Rasomycin LA has specially been developed to reduce the antibiotic treatment of animals to one injection.