Veterinary formulations Flashcards
Which OTC drug is toxic to cats?
paracetamol
What food is toxic to dogs?
chocolate
Why is it necessary to make special formulations for animals?
animals
- are susceptible to different diseases = mastitis in cows, heart worm in cats
- have different physiology = skin thickness in cows, size variation
- have different metabolism = paracetamol helps humans but is toxic to cats
What does zoonoses mean?
Zoonotic diseases are diseases that can be transmitted between animals and humans via direct or indirect contacts
How can animals be classed?
animals be classed according to their dietary consumption
- carnivores
- herbivores
- omnivores
What are the features of carnivores GIT? What is the relation between carnivores and absorption?
carnivores have a GIT reflecting diet low in fibre BUT high in fat and protein
- have a simple colon and well developed small intestine
carnivores have
- more gastric acid when fed
- fasted variable pH (3-8)
this means they have different bioavailability and absorption rate to humans
What are the properties of herbivores GIT?
grazing animals have a GIT reflecting diet high in fibre BUT low in fat and protein
they have a rumen (herbivores as thus also known as ruminants)
- herbivores with a 4 chambered stomach
What is the physiology of a ruminant?
the intestinal tract consists of the same structures of other animals but the stomach is
- large and complex
= has 4 compartments known as the reticulum, abomasum, omasum and rumen.
38-42°C
5-7pH
has a long retention time
results in absorbs nutrients and gases such as methane and ammonia
What is the function of the rumen?
acts as a storage unit for feed
absorbs nutrients through papillae of the rumen wall
facilitates fermentation of microbes and bacteria that are needed to
- breakdown and digest proteins
- digest cellulose and complex starch producing volatile fatty acid chains
- the microbes also synthesise proteins, B vitamins and vitamin K
What is the function of the reticulum?
traps heavy, dense or particles too large to digest
- larger particles are regurgitated and rechewed = rumination
- smaller particles go straight to the omasum
What is the function of the omasum?
absorbs water and water soluble nutrients
- due to it been lined with folds of tissue
acts as a filtration system and allows only small particles into the abomasum
What is the function of the abomasum?
acts most similarly to stomachs of other animals
is lined with glands that release hydrochloric acid and digestive enzymes that help further break down feed and plant material
What medicines are approved for used in animals?
fluoxetine (prozac) - separation anxiety in dogs
sildenafil (viagra) - pulmonary hypertension in canines
alprazolam - anxiety of noise phobias (thunder or fireworks)
ketamine - sedative in animals
How are drugs most commonly administered to herd animals? What are the advantages and disadvantages?
liquid (solution) or suspensions that are typically delivered by gun
- has a large reservoir, fixed volume and long nozzle
- is only suited for one off treatments = time consuming, stressful to the herd and impractical for repeated doses
What are the benefits of controlled drug delivery in animals?
reduction of pain and distress to the animal
ability to tailor pharmaceutics around the constraints of farm management systems
financial benefits to the end user
improved therapeutic outcomes
What are the benefits and issues associated with rumen-reticulum devices (RRD)? How can the issues be avoided?
rumen-reticulum anatomy and physiology allows for long term retention devices in the rumen
factors that affects device use
- regurgitation reflexes and the conditions found in the rumen environment
to avoid regurgitation reflexes - use objects that are dense enough to stay toward the bottom of the rumen but not pass to the abomasum, use objects that are difficult to regurgitate
How can rumen-reticulum devices be monitored?
portholes (fistulas) are made
- openings on the side of a cow that allows access to an animals stomach with a cannula or with your hands
What are the features of the Captec device?
- used for treat sheep with albendazole (parasitic worm infections)
has polymeric wings
- wings are held against the cylindrical body via water soluble tape/adhesive
in the rumen, the tape dissolves allowing the wings to pop open thus preventing abomasum passage
controlled release is mediated by erosion (stacked tablet formulation)
- base allows erosion through holes
What are the features of the rumens RDD for cattle?
has polymeric wings
- wings are held against the cylindrical body via water soluble tape/adhesive
inside the cylinder, it has
- hydrolysable co-polymer = erosion depends on polylactic/polyglycolic acid
- crystalline drug = a polyether antibiotic which reduces bloating and accelerates growth
What are the features of the paratex flex?
- contains morantel tartrate for parasitic gastroenteritis
is a rigid, trilaminar sheet
- is rolled and held via water soluble adhesive ring for administration as a bolus
once the ring dissolves in the rumen, the RRD assumes its expanded form to prevent regurgitation
- has an erodable matrix core and insoluble polymer coat
release is facilitated by erosion then diffusion
Why must animal dosages be delivered directly into the pharynx?
animals are typically uncooperative
- delivery deep into the pharynx triggered reflex swallowing and delivery into the rumen
What are the benefits of injection formulation for animals? What are the types available?
is less stressful to the animal
is easier to administer for the farmer
is faster to administer for the farmer
cydectin for cattle/sheep
- moxidectin to control parasites
What drugs can be administered to animals via food?
levamisole soluble pig wormer
- reconstituted powder is given via water
safeguard dewormer for cattle
- is a solid feed additive
- is only suitable for wide therapeutic index
What drugs can be administered to animals topically?
frontline
- is applied topically over fur
- is fast and low stress but is less precise than injections
