Pharmaceutics

• Pharmaceutics


  The scientific and technological aspects of the design and manufacture of dosage forms
• The term 'pharmaceutics' is used in pharmacy and the pharmaceutical sciences to encompass a wide range of subject areas that are all associated with the steps to which a drug is subjected towards the end of its development
• Pharmaceutics converts a drug into a medicine
• Drug


  The pharmacologically active ingredient in a medicine
• Medicine


  A drug-delivery system, a way of administering drug(s) to the body in a safe, efficient, accurate, reproducible and convenient manner
• Pharmaceutical care


  The care that a given patient requires and receives which assures rational drug usage
• History of drug discovery

  • Herbal drugs and serendipitous discoveries
  • Vitamins and vaccines
  • Antibiotic era
  • New technology and discovery of DNA
  • Breakthrough in etiology
  • Rise of biotechnology
  • Use of IT
  • Commercialization of drug discovery
  • Combinatorial chemistry and robotics automation
• Pre-discovery target identification


  1. Define the medical need (disease)

  2. Demonstrate that target is relevant to disease mechanism

  3. Understand the molecular mechanism of the disease

  4. Identify a therapeutic target
• Drug discovery


  1. Identify a lead compound

  2. Lead optimization: Optimize to give drug-like properties 3.Pharmacokinetics, metabolism, off-target

  activities

  4. Safety assessment, Preclinical Candidate
• In vitro studies


  Studies using component of organism i.e. test tube experiments
• In vitro studies


  • Studies can be completed in short period of time
  • Reduces risk in post clinical trials
  • Permit an enormous level of simplification of the system
  • Investigator can focus on a small number of variables
• In vivo studies


  Experimentation using a whole, living organism
• Preclinical study


  1. Pharmacology and toxicology

  2. Process chemistry

  3. Pharmaceutics

  4. More studies to determine safety and efficacy

  5. Develop a process to make a drug substance

  6. Formulate the drug product
• Toxicology studies


  • Acute toxicity
  • Repeated dose toxicity
  • Chronic toxicity
• Clinical trials


  1. Phase I: Healthy volunteers

  2. Phase II: Diseased subjects

  3. Phase III: Clinical research

  4. Phase IV: FDA drug review
• New Drug Application (NDA)

  Summary of all work done to date including data from IND, additional data on preclinical, drug substance and product manufacturing, animal studies, clinical trial results
• Review process for NDA can take up to 18 months
• Information learned from clinical trials

  • Effectiveness in treating disease
  • Short-term side effects in health-impaired patients
  • Dose range
  • Absorption and metabolism
  • Effects on organs and tissue
  • Side effects as dosage is increased
  • Benefit/risk relationship of drug
  • Less common and longer term side effects
  • Labeling information
• Parenteral administration is injection or infusion by means of a needle or catheter inserted into the body
• Requirements for parenteral preparations

  • Sterility
  • Pyrogen free
  • Free from particulate matter
  • Clarity
  • Stability
  • Isotonicity
  • Specific and high-quality packaging
• Why parenteral route is used

  • Rapid action
  • Oral route cannot be used
  • Not effective except as injection
  • Many new drugs particularly those derived from new development in biotechnology can only be given by parenteral as they are inactivated in GIT if given orally
  • New drugs require to maintain potency & specificity so they are given by parenteral
• Advantages of parenteral route

  • Rapid onset of action
  • Can provide fluids, electrolytes, and nutrition to patients who cannot take food or have serious problems with the GI tract
  • Provides higher concentration of drug to bloodstream or tissues
  • Advantageous in serious bacterial infection
  • IV infusion provides a continuous amount of needed medication without fluctuation in blood levels
  • Infusion rate can be adjusted
  • Suitable for drugs which are not administered by oral route
  • Useful for unconscious or vomiting patients
  • Duration of action can be prolonged by modifying formulation
  • Suitable for nutritive like glucose & electrolyte
  • Suitable for drugs inactivated in GIT or HCl
• Disadvantages of parenteral route

  • Once injected cannot be controlled (retreat)
  • Injections may cause pain at the site of injection
  • Only a trained person is required
  • If given by wrong route, difficult to control adverse effect
  • Difficult to save patients if overdose
  • Sensitivity or allergic reaction at the site of injection
  • Requires strict control of sterility & nonpyrogenicity than other formulations
  • Potential for introducing toxic agents and microbes pyrogenes
• Why dosage form is required

  • To provide for the safe and convenient delivery of accurate dosage
  • For the protection of a drug substance from the destructive influence of environment
• Suitable for the drugs which are not administered by oral route
• Useful for unconscious or vomiting patients
• Duration of action can be prolonged by modifying formulation
• Suitable for nutritive like glucose & electrolyte
• Suitable for the drugs which are inactivated in GIT or HCl (GI fluid)
• Once injected cannot be controlled (retreat)
• Injections may cause pain at the site of injection
• Only a trained person is required
• If given by wrong route, difficult to control adverse effect
• Difficult to save patients if overdose
• Sensitivity or allergic reaction at the site of injection
• Requires strict control of sterility & nonpyrogenicity than other formulations
• Potential for introducing toxic agents and microbes pyrogenes
• Dosage form


  To provide for the safe and convenient delivery of accurate dosage
• Examples of dosage forms


  • Tablets, Capsules, syrups
• Dosage form


  For the protection of a drug substance from the destructive influence of atmospheric oxygen or moisture