Amoxicillin Trihydrate + Colistin Sulphate is a combination of two antibiotics. Amoxicillin is a penicillin antibiotic that works by inhibiting bacterial cell wall synthesis, while Colistin is a polymyxin antibiotic that disrupts the cell membrane of bacteria, leading to cell death. The combination of these two antibiotics is used to provide a broad spectrum of antimicrobial activity against a variety of bacteria.