Roncycline 500 is an antibiotic medication containing 500 mg of doxycycline as the active ingredient. It is commonly used to treat a variety of bacterial infections, including respiratory, skin, and urinary tract infections. Doxycycline works by inhibiting the growth of bacteria, helping to prevent the spread of infections. It is important to follow the prescribed dosage and complete the full course of treatment to ensure effectiveness and prevent resistance.