Sources of Drugs

Sources of Drugs

• Drugs can originate from various sources, impacting their characteristics and potential side effects.

• Natural Sources: Many drugs are derived from plants, animals, and microorganisms.

  • Plants: Many medicinal plants contain active compounds with therapeutic properties. Examples include aspirin from willow bark, morphine from opium poppy, and digitalis from foxglove.
  • Animals: Some drugs are extracted from animal tissues. Insulin, derived from animal pancreases, was a crucial treatment for diabetes before genetically engineered versions became available. Certain venoms and tissues hold potential for bioactive compounds.
  • Microorganisms: Some antibiotics and other treatments, such as penicillin from Penicillium mold, are produced by microorganisms.

• Semi-synthetic Sources: These drugs are modified versions of naturally occurring compounds. The modifications enhance potency, extend duration of action, or limit side effects.

  • Examples include certain forms of morphine and codeine, which are modified from opium alkaloids.

• Chemical Synthesis: Many modern drugs are synthesized in laboratories through chemical reactions. This method allows precise control over the structure and purity of the molecule.

  • The chemical synthesis process involves precise manipulation of starting materials, catalysts, and reaction conditions, to create new molecules with desired therapeutic properties.
  • Benefits include creating complex structures not found in nature and producing large quantities of the drug at a controlled cost.
  • Examples include many synthetic analgesics, antibiotics, and other pharmaceuticals.

• Biotechnology: This encompasses the use of biological systems, mainly microorganisms, to manufacture drugs.

  • Genetically engineered microorganisms are used to produce drugs like insulin, human growth hormone, and vaccines.
  • This method has advantages regarding safety, cost-effectiveness, availability, and minimizing the need for harvesting from natural sources.
  • Example includes genetically modified bacteria that efficiently produce insulin for diabetes treatment.

Drug Extraction Methods

• Extraction: Techniques for isolating active compounds from natural sources. Common methods include solvent extraction (using organic solvents to dissolve the desired compound), liquid-liquid extraction, and supercritical fluid extraction.

  • These methods determine the purity and yield of the desired drug substance, and ensure safety and efficacy.

• Separation Techniques: Methods used to isolate the active compounds from the source material while minimizing impurities.

  • Chromatography, including high-performance liquid chromatography (HPLC) and gas chromatography (GC), is frequently used to separate different components within complex mixtures. These methods are crucial in purifying isolated compounds.
  • Crystallization is another frequently used method to purify substances based on differences in solubility.

Factors Affecting Drug Source Selection

• Availability: The abundance of the natural source and ease of extraction.
• Cost-effectiveness: Producing synthetic drugs can be more economical than extracting from limited natural sources.
• Complexity: Some natural sources are complex leading to difficulty in isolating and purifying the desired compound; sometimes easier to synthesize.
• Safety: Important consideration to avoid undesirable side effects from natural compounds of unknown safety, including potential allergies.
• Purity: Techniques for purifying a compound to make it clinically acceptable. Important for ensuring a consistent therapeutic effect.
• Regulation: Strict guidelines and regulatory hurdles to prove safety and efficacy before a pharmaceutical is used in humans or veterinary medicine.
• Sustainability: Careful consideration of the environmental impact and sustainability of sourcing ingredients.
• Quantity: Requirements for large-scale production and availability of supply to meet market demand.