May 30, 2024

Efflorescent, Hygroscopic, and Deliquescent powders

Efflorescent, Hygroscopic, and Deliquescent powders

Hygroscopic and Deliquescent Powders

Hygroscopic and deliquescent powders are terms used to describe certain characteristics of powders in the field of pharmaceuticals. Here’s an explanation of each term:

  1. Hygroscopic powders:
    Hygroscopic powders have a property of absorbing moisture from the surrounding environment. When exposed to air, these powders can attract and retain water molecules, causing them to become damp or even dissolve. The absorption of moisture can lead to changes in the physical and chemical properties of the powder, such as altered particle size, texture, and stability. This property can pose challenges in the formulation and storage of hygroscopic drugs, as the absorbed moisture can affect the drug’s potency, dissolution rate, and overall stability.

To mitigate the hygroscopic nature of a powder, pharmaceutical manufacturers may take measures such as using desiccants in packaging or incorporating moisture-resistant coatings on tablets or capsules. These strategies help preserve the integrity and efficacy of the medication.

  1. Deliquescent powders:
    Deliquescent powders are even more hygroscopic than regular hygroscopic powders. Deliquescence refers to the process in which a substance absorbs so much moisture from the air that it dissolves and forms a liquid solution. Deliquescent powders have a strong affinity for water and can rapidly absorb moisture, leading to their transformation into a liquid or semi-solid state.

In pharmaceuticals, deliquescent powders can present challenges in formulation, as their tendency to liquefy can affect the dosage form’s integrity, uniformity, and stability. Special considerations need to be taken when handling and packaging deliquescent drugs to ensure their potency and shelf life are preserved.

It is important for pharmaceutical manufacturers and pharmacists to be aware of the hygroscopic and deliquescent properties of powders to ensure proper handling, storage, and formulation of medications.

Hygroscopic and Deliquescent Powders examples

Ammonium bromide, Ammonium chloride, Ammonium iodide, Calcium bromide, Calcium chloride, Ephedrine sulfate, Hydrastin hydrochloride, Hydrastine sulfate, Hyoscyamine hydrobromide, Hyoscyamine sulfate, Iron and ammonium citrate Lithium bromide, Pepsin, Phenobarbital sodium, Physostigmine hydrobromide, Physostigmine hydrochloride, Physostigmine sulfate, Pilocarpine alkaloid, Potassium acetate, Potassium citrate, Sodium bromide, Sodium iodide, Sodium nitrate, Zinc chloride

Efflorescent Powders

In pharmaceuticals, efflorescent powders refer to powdered substances that have the ability to lose water molecules when exposed to air, resulting in the formation of a crystalline deposit on the surface. This process is known as efflorescence.

Efflorescent powders are typically hygroscopic, meaning they have a tendency to absorb moisture from the surrounding environment. When these powders absorb moisture, they may dissolve, undergo chemical reactions, or undergo physical changes such as caking or clumping. This can lead to changes in the powder’s physical and chemical properties, which can impact its effectiveness and stability.

Efflorescence is an important consideration in pharmaceutical formulation and manufacturing processes. It is particularly relevant in the development of solid dosage forms such as tablets and capsules, where the presence of moisture can affect the drug’s stability, dissolution rate, and overall performance.

To minimize the effects of efflorescence, pharmaceutical manufacturers often take measures to protect efflorescent powders from exposure to moisture. These may include using appropriate packaging materials, employing moisture barrier technologies, or adding desiccants to the packaging to absorb excess moisture.

It’s important to note that not all powders used in pharmaceuticals are efflorescent. Some powders may be deliquescent, meaning they have a tendency to absorb so much moisture from the air that they dissolve completely. Others may be non-hygroscopic and remain stable even in the presence of moisture.

Overall, understanding the efflorescent properties of powders used in pharmaceuticals is crucial for ensuring the stability, quality, and efficacy of drug products.

Efflorescent Powders examples

Atropine sulfate, Caffeine, Calcium lactate, Citric acid, Cocaine, Codeine, Codeine phosphate, Codeine sulfate, Ferrous sulfate, Morphine acetate, Quinine bisulfate, Quinine hydrobromide, Quinine hydrochloride, Scopolamine hydrobromide, Sodium acetate, Sodium carbonate (decahydrate), Sodium phosphate, Strychnine sulfate, Terpin hydrate


What is difference between Hygroscopic, Deliquescent and Efflorescent Powders

Hygroscopic, deliquescent, and efflorescent powders are terms used to describe the moisture-absorbing or moisture-releasing properties of substances. Here’s a breakdown of the differences between these terms:

  1. Hygroscopic powders:
    Hygroscopic powders have the ability to absorb and retain moisture from the surrounding environment. They attract water molecules, causing the powder to become damp or even dissolve. The absorbed moisture can alter the physical and chemical properties of the powder. Hygroscopic substances do not necessarily dissolve completely in the absorbed moisture; rather, they retain the absorbed water as a hydrated form. Examples of hygroscopic substances in pharmaceuticals include certain salts and sugar alcohols.
  2. Deliquescent powders:
    Deliquescent powders are substances that are highly hygroscopic and can absorb moisture to the extent that they dissolve completely, forming a liquid solution. These powders have a strong affinity for water and can absorb it from the atmosphere until they become liquid or semi-solid. Deliquescent substances often have a higher moisture content than hygroscopic substances. Examples of deliquescent substances include certain salts like calcium chloride and potassium hydroxide.
  3. Efflorescent powders:
    Efflorescent powders, on the other hand, release moisture when exposed to air. These substances contain water of crystallization within their structure. When the powder is exposed to a drier environment, the water of crystallization evaporates, causing the powder to lose moisture and sometimes crumble or become powdery. The moisture loss can lead to changes in the physical appearance and properties of the powder. Efflorescence is often observed as a powdery residue or crystal formation on the surface of the substance. Efflorescence can occur in certain salts like sodium carbonate and magnesium sulfate.

In summary, hygroscopic powders absorb and retain moisture, deliquescent powders absorb moisture to the point of dissolving, and efflorescent powders release moisture when exposed to drier conditions. These properties have implications for the handling, storage, and formulation of pharmaceutical substances, and it is important to consider these characteristics when working with powders in the pharmaceutical industry.


First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise

F Y B Pharm Sem-IS Y B Pharm Sem-II
BP101T Human Anatomy and Physiology I TheoryBP201T Human Anatomy and Physiology II – Theory
BP102T Pharmaceutical Analysis I TheoryBP202T Pharmaceutical Organic Chemistry I Theory
BP103T Pharmaceutics I TheoryBP203T Biochemistry – Theory
BP104T Pharmaceutical Inorganic Chemistry TheoryBP204T Pathophysiology – Theory
BP105T Communication skills TheoryBP205T Computer Applications in Pharmacy Theory
BP106RBT Remedial BiologyBP206T Environmental sciences – Theory
BP106RMT Remedial Mathematics TheoryBP207P Human Anatomy and Physiology II Practical
BP107P Human Anatomy and Physiology PracticalBP208P Pharmaceutical Organic Chemistry I Practical
BP108P Pharmaceutical Analysis I PracticalBP209P Biochemistry Practical
BP109P Pharmaceutics I PracticalBP210P Computer Applications in Pharmacy Practical
BP110P Pharmaceutical Inorganic Chemistry Practical
BP111P Communication skills Practical
BP112RBP Remedial Biology Practical

Suggested readings:


  • Regenerative Medicine: Rejuvenating the Body’s Natural Healing Potential

  • A Legacy of Loss: The Contaminated Blood Scandal and Haemophilia

  • Percutaneous Aortic Valve Replacement (TAVR): A Minimally Invasive Option for Heart Valve Disease


https://youtu.be/fMRNcXa9gBo