Some common medicinal preparations contain diazepam with aluminium Hydroxide, there may be other compounds [e.g. magnesium trisilicate and polydimethylsiloxane with Aluminum Hydroxide and Diazepam as ingredients of Tablet Peptica ( Geno pharmaceuticals)]. These drugs are commonly used as antacids. We can see in the drug Peptica that Aluminum Hydroxide and Magnesium Trisilicate were included for neutralizing the acidity (HCl) of stomach.....thus serving their purpose as antacids. Polydimethylsiloxane is a carminative preparation ('Carminative' means preparations that expulse gas from the gastrointestinal tract or prevent its formation). But what is the need for adding Diazepam here?