A synergistic antibiotic formulation comprising: a penicillinase resistant penicillin in an amount of about 30 to 75 % by mass of the total formulation, 60 to 90 % of the penicillinase resistant penicillin being sustained release, the remaining penicillinase resistant penicillin being immediate release together with cetixime trihydrate in an amount of about 15 to 40 % of the total mass of penicillinase resistant penicillin and lactobacillus sporogenes in amount of about 05 to 4 % of the total mass of penicillinase resistant penicillin and pharmaceutically acceptable excipients.