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  • Impurities in Pharmaceutical Drug Substances

    Impurities are defined as foreign particle that affects the purity of a substance. Usually, impurities occurring in many pharmaceutical or medicinal preparations may be of the following types.

    • A foreign particle that brings about adverse or toxic reactions when present in excess beyond its limits. Examples: lead, heavy metals, arsenic, etc.
      • Impurities may not cause toxic effects but bring about deterioration of the activity of chemicals. Example: hard soap containing an excess of water.
      • Impurities that cause incompatibility of the active ingredient with other substances or which reduce the properties of the active ingredient.

    1) Types of pharmaceutical drug substances:

    There are several types of drug substances (Medicine) in the world of medicine like

    • Liquid – The active part of the medicine is combined with a liquid to make it easier to take or better absorbed. A liquid may also be called a ‘mixture’, ‘solution’, or ‘syrup’. Many common liquids are now available without any added coloring or sugar.
    • Tablet – The active ingredient is combined with another substance and pressed into a round or oval solid shape. There are different types of tablets. Soluble or dispersible tablets can safely be dissolved in water. 
    • Capsules – The active part of the medicine is contained inside a plastic shell that dissolves slowly in the stomach. You can take some capsules apart and mix the contents with your child’s favorite food. Others need to be swallowed whole, so the medicine isn’t absorbed until the stomach acid breaks down the capsule shell.
    • Topical medicines – These are creams, lotions or ointments applied directly onto the skin. They come in tubs, bottles or tubes depending on the type of medicine. The active part of the medicine is mixed with another substance, making it easy to apply to the skin.
    • Suppositories – The active part of the medicine is combined with another substance and pressed into a ‘bullet shape’ so it can be inserted into the bottom. Suppositories mustn’t be swallowed.
    • Drops – These are often used where the active part of the medicine works best if it reaches the affected area directly. They tend to be used for the eye, ear,s or nose.
    • Inhalers – The active part of the medicine is released under pressure directly into the lungs. Young children may need to use a ‘spacer’ device to take the medicine properly. Inhalers can be difficult to use at first so your pharmacist will show you how to use them.
    • Injections – There are different types of injection, in how and where they’re injected. Subcutaneous or SC injections are given just under the surface of the skin. Intramuscular or IM injections are given into a muscle. Intrathecal injections are given into the fluid around the spinal cord. Intravenous or IV injections are given into a vein. Some injections can be given at home but most are given at your doctor’s surgery or in the hospital.
    •  Etc.

     The major, main and important content of the medicine is Active pharmaceutical ingredient (API), preservatives, etc.

    2) Types of Impurities in pharmaceutical drug substances:

    According to the ICH, guideline impurities are classified as organic impurities, inorganic impurities, and residual solvents.

    • Organic impurities – The impurities due to Starting materials, By-products, Intermediates, Degradation products, Reagents, ligands, and catalysts.
    • Inorganic impurities – Inorganic impurities may be derived from the manufacturing process and are normally known and identified as reagents, ligands, inorganic salts, heavy metals, catalysts, filter aids, charcoal, etc.
    • Residual solvents – Residual solvents are the impurities introduced with solvents i.e. Class 1- Solvents To Be Avoided, Class 2 – Solvents To Be Limited, Class 3 – Solvents with Low Toxic Potential.

    Basically, Veeprho laboratories Pvt Ltd involves in the synthesis of organic impurities i.e. The impurities due to Starting materials, By-products, Intermediates, Degradation products, Reagents, ligands, and catalysts.