INTRODUCTION TO DRUG DELIVERY SYSTEM

Drugs

Substances intended for use in the diagnosis, cure, treatment, or prevention of disease in human or animals.

Substances that bring changes in biologic function through its chemical actions.

May be synthesized within the body. E.g: Insulin, estrogen.

May be derived from natural products or chemicals

COSMETIC: Product intended to be rubbed, poured, sprinkled or sprayed on, introduced into, or otherwise applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance.

PRODUCT CAN BE
A COSMETIC AND
A DRUG:


Antidandruff shampoo

  • Cleanses hair, treats dandruff.

Moisturizer with SPF

  • Beautifies skin, prevents cancer.

PRODUCT SAFETY
ADVERSE DRUG REACTION

A response to a drug which is noxious and unintended and which occurs at doses normally used in man for prophylaxis, diagnosis, or therapy of disease or for modification of physiological function.

Patient injury caused by a medicine taken in therapeutic doses.

E.g: ANAPHYLAXIS
An acute allergic reaction to an antigen (foreign compound) to which body has become hypersensitive

TYPES OF ADR

TYPE A

  • Exaggerated pharmacological response
  • Not suitable for asthma patient

TYPE B

  • Non-pharmacological
  • Allergic reactions (e.g, penicillin, anaphylaxis)

TYPE C

  • Continuous or long term
  • Osteoporosis with oral steroids

TYPE D

  • Delayed (lag time)
  • Tetratogenic effects with anticonvulsants

TYPE E

  • Withdrawal syndrome (addiction) with benzodiazepines

TYPE F

  • Failure of efficacy (no response)
  • Resistance to antimicrobial

ADR MANAGEMENT

STEP 1. Evaluate the nature of the event

  • Obtain detailed history of the patient
  • Classify severity of the reaction
    i. Severe (fatal or life threatening)
    ii. Moderate (hospitalization)
    iii. Mild (symptoms require discontinuation of therapy)
    iv. Incidental (mild, patient can choose to continue or not)

STEP 2. Establish the cause

  • Use the Naranjo algorithm to assess the patient's reaction
  • Evaluate the quality of the medicine

STEP 3. Take corrective and follow-up action

  • Will depend on cause and severity
  • Educate and monitor prescribers
  • Notify drug regulatory authorities and manufacturers
  • Educate and warn patients

DRUG DELIVERY

The method or process of administrating
pharmaceutical compound to achieve a
therapeutic effect in humans or animals

Enternal

  • Oral
  • Sublingual
    Rectal/Suppository

Parenteral

  • Intravenous
  • Intramuscular
  • Subcutaneous
  • Intradermal
  • Intraosseous

Topical

  • Skin
  • Oral inhalation
  • Nasal inhalation
  • ENTERNAL
  • ORAL
  • Safest, most common, convenient, economical
  • Non invasive and painless
  • Don't need to be sterile so drugs is cheaper
  • Limitation:
    i. Slow action, not suitable for emergency
    ii. May causes nausea and vomiting
    iii. Had to go through First Pass Metabolism
    iv. Absorption of drug is varied
  • Dosage forms:
    Capsules, powders, tablets, syrup,
    emulsion, suspension
  • SUBLINGUAL
  • Place under tongue or buccal allows drug to diffuse into network and enter the systemic circulation directly under tongue or crushed in mouth and spread over the buccal mucosa
  • Absorption is relatively rapid action can be produce in a minutes
  • Limitation: Inconvenient, one can spit the drug once the desired action of drug obtained
  • Advantages: Liver and gut are by passed. Drugs are protected from first pass metabolism and drugs are directly into the systemic circulation. (E.g, Lorazepam, treat anxiety)
  • Dosage forms:
    Tablets, lozenges, gum.
  • RECTAL / SUPPOSITORY
  • Certain irritating and unpleasant drug for their systemic effect
  • In this form, drug is mixed with a waxy substances that dissolves or liquefies after it is inserted into the rectum
  • Absorption is slower, irregular and unpredictable
  • Rectal inflammation can occur
  • E.g. Diazepam, paraldehyde, ergotamine
  • PARENTERAL
  • Introduce drugs directly across the body's barrier defense into the systemic circulation
  • Drugs that are poorly absorbed from the GIT (heparin) and agents that are unstable in GIT (insulin)
  • For unconscious patients and circumstances where rapid onset of action needed
  • Limitation: Irreversible, cause pain, fear, local tissue damage, infections.
  • Advantage: Highest bioavailability and not subject to first pass metabolism
    Major: IV, IM, SC
  • IV
  • Placing drug directly into bloodstream
  • Advantage:
    Precise, accurate, immediate onset of action, 100% bioavailability
  • Disadvantage:
    i. Risk of embolism, a blockage causing piece of material, inside of blood vessel.
    ii. High concentration attained rapidly leading to greater risk of adverse effects
  • IM
  • Into skeletal muscle
  • The best site is deltoid muscke in the shoulder or the gluteus muscle in the buttocks
  • Advantage:
    Suitable for injection of drug in aqueous solution (rapid action) and drug in suspension or emulsion (sustained release)
  • Disadvantage:
    Pain at injection sites for certain drugs
  • TOPICAL
  • Produce local effect to:
  • Skin (percutaneous):
    E.g. Allergy testing, topical local anesthesia.
  • Mucous membrane of respiratory tract (oral inhalation):
    E.g. Asthma / Nebulizer
  • Nasal inhalation:
    E.g. Decongestant nasal spray
  • Ear drops. Applying drug into ear canal:
    E.g. Otitis externa
  • Eye drops. Ocular administration is the application of a drug to the eye. Conjunctival mucosa or lining of the inside of the eyelid
    E.g. Conjunctivitis

Topical Dose Forms

  • Skin
    i. Creams
    ii. Ointments
    iii. Lotions
    iv. Gels
  • Nasal
    i. Sprays
    ii. Aerosol (pressure)
    iii. Drops (instillation)
  • Eye or Ear
    i. Solutions
    ii. Suspensions
    iii. Ointments

FACTORS INFLUENCE DRUG ROUTE

Physical and chemical properties of drugs

Rate and extent of drug absorption

Rapidity at which response is desired

Accuracy of dose required

Condition of patients

Effect of digestive juice and
first pass metabolism of drugs

Site of desire action

BENEFITS OF ADDS

Optimum dose at right time and right location

Efficient use of expensive drugs,
excipients and reduction in production cost

Beneficial to patients, better therapy,
improved comfort, improved patient compliance

Reduced rate of rise of drug concentration
in blood. Thus, reduced side effects

To achieve a targeted drug release