DISPENSING OF POWDERS INVOLVING SPECIAL PROBLEMS Name Dr

DISPENSING OF POWDERS INVOLVING SPECIAL PROBLEMS Name : Dr. Smt. Rupali Thorat. Name of College : VJSM’S Institute of Pharmacy, Ale e-mail : rupali. 78@ rediffmail. com

LEARNING OBJECTIVES At the end of session student will be able to: § List of Different Powders. § Explain Problems, Solution & Examples. § Dispensing of Powders Involving Special Problems.

LIST OF DIFFERENT POWDERS § § § Hygroscopic and Deliquescent Powder Efflorescent powders Eutectic Mixtures Potent Drug Explosive mixtures

HYGROSCOPIC & DELIQUESCENT POWDER Problem : Absorption of moisture from air leading to liquefaction. Solution: 1. Applied in a granular form to decrease the exposed surface to air. 2. Packed in aluminum foil or Plastic Cover. Examples : Ammonium Chloride, Iron, Ammonium Citrate, Pepsin, Phenobarbitone, Sodium bromide, Sodium Iodide, Potassium Citrate, Zinc chloride.

EFFLORSCENT POWDER Problem : Crystalline substances which during storage loose their water of crystallization and change to powder(to be efflorescent). The liberated water convert the powder to a paste or to a liquid. Solution: 1. Using the anhydrous salt or Inert Substance. Examples : - Caffeine, Ferrous sulfate, citric acid.

EUTECTIC MIXTURES Problem: Mixture of substances that liquefy when mixed, rubbed or triturated together. The melting points of many eutectic mixtures are below room temperature. Solution: 1. Using inert adsorbent such as starch, talc, lactose to prevent dampness of the powder. 2. Dispensing the components of the eutectic mixture separately. Examples: Menthol, Thymol, Phenol, Camphor.

POTENT DRUG Problem: Limited precision and accuracy of the used balances to weight small amounts of potent drugs. Solution: Drug triturates 1. Suitable diluents like lactose are mixed with the potent drug to form 10 - 20%w/w drug triturates. 2. Very fine powders should be used in the triturates 3. Geometric dilution to prepare drug triturates. Examples: Codeine Phosphate, Prednisone.

EXPLOSIVE MIXTURES Problem: Oxidizing agents explore violently when triturated in a mortar with a reducing agent. Solution: 1. Comminute each salt separately. 2. Subject to a minimum pressure. Examples: Pot. Salts of chlorate, dichromate, permanganate and nitrate. Sod. Peroxide- silver nitrate and silver oxide , Sulfides sulfur tannic acid- charcoal.

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