Pharmaceutical-grade lime powder is primarily calcium hydroxide (
š¶š(šš»)2Ca(OH)2cap C a open paren cap O cap H close paren sub 2
), also known as hydrated or slaked lime. It is a high-purity, free-flowing white powder used in medicinal formulations, antacids, and dental treatments.
Chemical identity and grades
- Chemical name: Calcium hydroxide.
- .Formula:š¶š(šš»)2Ca(OH)2cap C a open paren cap O cap H close paren sub 2
- Common names: Hydrated lime, slaked lime.
- Pharmaceutical grades: It is manufactured to meet rigorous international standards like United States Pharmacopeia (USP), European Pharmacopoeia (EP), British Pharmacopoeia (BP), and Indian Pharmacopoeia (IP) to ensure high purity and safety for medical use.
Pharmaceutical applications
- Antacid formulations: Its alkaline properties are used to neutralize stomach acid, making it an ingredient in some antacid products for relieving indigestion and heartburn.
- Dental treatments: In endodontics, it serves as a root canal dressing with antibacterial properties. Its high pH helps disinfect the canal and encourages the formation of a hard tissue barrier to promote healing.
- Topical preparations: It is used in ointments, lotions, and creams for treating minor skin irritations and rashes, and as a component in calamine lotion due to its soothing effects.
- pH modification: It is employed as a neutralizing agent or pH buffer in various pharmaceutical formulations where calcium is needed.
- Excipient and filler: The fine powder can be used as a filling agent or excipient in tablet and capsule formulations.
- Chemical synthesis: It functions as a basic catalyst in some chemical processes, such as the production of atorvastatin calcium.
Important considerations
- High purity is essential: Only specially prepared pharmaceutical-grade calcium hydroxide should be used for medical applications. Industrial grades can contain impurities that are harmful if ingested or applied topically.
- Alkaline nature: Calcium hydroxide is a strong alkali with a high pH (around 12.4 in solution), so it must be handled carefully. It can cause skin irritation and is caustic, meaning protective equipment should be worn during handling to avoid burns and respiratory problems if inhaled.
- Dental side effects: While effective in endodontics, prolonged use in dental procedures can potentially cause structural changes in dentin and increase the risk of tooth fracture, especially in immature teeth.
- Quality control: Reputable manufacturers of pharmaceutical-grade calcium hydroxide follow Good Manufacturing Practices (GMP) and perform rigorous quality control to ensure consistency and compliance with pharmacopoeia standards.