Intro to Vet

Drug delivery strategies for veterinary formulations are complicated by;

  • Diversity of species and breeds
  • Wide range of body sizes
  • Different husbandry practices
  • Seasonal variations
  • Costs constraints associated with the value of the animal
  • Drug residues in food and fiber

Peculiarities of anatomy and physiology of animals and birds has led to development of specialized dose forms, and administration by unusual routes

Most special dosage forms have been developed for ruminants e.g. boluses and intraruminal injections

Pour on formulations

Differences in physiology leading to different pharmacokinetics e.g., aspirin in cats (longer half life) Monensin and avermectins are toxic in horses

Behavioral characteristics

Factors considered in selecting medicines

Dose and frequency of administration

The optimal routes for delivery

The particular pharmaceutical forms to be used

Any public health or environmental implications and regulatory constraints

Types of medicines

Prophylactic medicines

Therapeutic medicines

Other medicines

Prophylactic medicines

These are designed to prevent disease and parasitic
infestation

They include:

  • Endoparasiticides - prevent and treat infestations by parasites that invade the body such as worms, flukes or coccidial protozoa
  • Exoparasiticides - prevent and treat infestation by parasites that live on the outside of the animal such as mites, ticks, fleas
  • Endectocides - prevent and treat infestation of both types of parasites
  • Vaccines - prevent diseases caused by certain viral or bacterial infections
  • Antiseptics prevent or minimise bacterial contamination

Therapeutic Medicines - used to treat disease

  • Antibiotics
  • Hormones treat reproductive problems
  • Anti inflammatories
  • Sedatives
  • Cardiovascular drugs
  • Drugs acting on the gastrointestinal tract
  • Immunological products

Other medicines

  • Digestive enhancers approved antibiotics to help farm animals get the maximum benefit from their feed
  • Anesthetics include pain killers and euthanasia products
  • Dietary supplements these are used to treat or prevent specific dietary deficiencies, rather than nutritional supplements

Types of Presentations

  • Injections

  • Intramammaries

  • Oral liquids - drenching

  • liquids for oral or ocular use (Multidose containers or single dose vials )

  • Oral solid-dose forms

  • topical

Examples of oral solid dosage forms

  • bolus (paste in cylindrical mass) e.g. fenbendazole
  • bullets ; given using dosing gun eg magnesium
  • capsules
  • granules and pellets
  • tablets / pills
  • oral paste and gels
  • pessaries and suppositories
  • sprays and aerosols

examples of topical drugs

  • dips
  • ear tags
  • foam
  • pour-on and spot-on
  • dusting powders
  • ointments and creams
  • gel
  • liniments and embrocations
  • shampoo
  • lotions

General characteristics of veterinary medicines

  • safety for humans
  • safety for animals
  • convenience of use
  • palatabilty
  • cost
  • efficacy
  • withdrawal period - the time which passes between the last dose given to the animal and the time when the level of residues in the tissues or products falls below the maximum residue limit (MRL)