Pharmacopeial Specifications:
- Identification: Positive for magnesium and hydroxide
- Assay (Mg(OH)₂ content): 95.0%–100.5%
- Loss on Ignition: 30.0%–33.0%
- Acid Neutralizing Capacity: Not less than 110 mEq/g
- Microbial Limits: Complies with pharmacopeial standards
Applications in Pharmaceutical Formulation:
- Antacid: Used in chewable tablets and oral suspensions to neutralize gastric acid.
- Laxative: Administered orally as a saline laxative, typically in milk of magnesia formulations.
- pH Modifier: Acts as an alkalizing agent in some formulations.
- Suspending Agent: Helps maintain uniformity in suspensions.
Comments:
Magnesium hydroxide is widely used for its dual action as an antacid and laxative. It has a rapid onset of action and a high acid-neutralizing capacity. In large doses, it may cause diarrhea, and it is often combined with aluminum-containing compounds to balance GI effects.
