Veterinary formulations

Question 1

Which OTC drug is toxic to cats?

Answer 1

paracetamol

Question 2

What food is toxic to dogs?

Answer 2

chocolate

Question 3

Why is it necessary to make special formulations for animals?

Answer 3

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

Question 4

What does zoonoses mean?

Answer 4

Zoonotic diseases are diseases that can be transmitted between animals and humans via direct or indirect contacts

Question 5

How can animals be classed?

Answer 5

animals be classed according to their dietary consumption

• carnivores
• herbivores
• omnivores

Question 6

What are the features of carnivores GIT? What is the relation between carnivores and absorption?

Answer 6

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

Question 7

What are the properties of herbivores GIT?

Answer 7

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

Question 8

What is the physiology of a ruminant?

Answer 8

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

Question 9

What is the function of the rumen?

Answer 9

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

Question 10

What is the function of the reticulum?

Answer 10

traps heavy, dense or particles too large to digest
- larger particles are regurgitated and rechewed = rumination
- smaller particles go straight to the omasum

Question 11

What is the function of the omasum?

Answer 11

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

Question 12

What is the function of the abomasum?

Answer 12

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

Question 13

What medicines are approved for used in animals?

Answer 13

fluoxetine (prozac) - separation anxiety in dogs

sildenafil (viagra) - pulmonary hypertension in canines

alprazolam - anxiety of noise phobias (thunder or fireworks)

ketamine - sedative in animals

Question 14

How are drugs most commonly administered to herd animals? What are the advantages and disadvantages?

Answer 14

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

Question 15

What are the benefits of controlled drug delivery in animals?

Answer 15

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

Question 16

What are the benefits and issues associated with rumen-reticulum devices (RRD)? How can the issues be avoided?

Answer 16

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

Question 17

How can rumen-reticulum devices be monitored?

Answer 17

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

Question 18

What are the features of the Captec device?
- used for treat sheep with albendazole (parasitic worm infections)

Answer 18

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

Question 19

What are the features of the rumens RDD for cattle?

Answer 19

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

Question 20

What are the features of the paratex flex?
- contains morantel tartrate for parasitic gastroenteritis

Answer 20

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

Question 21

Why must animal dosages be delivered directly into the pharynx?

Answer 21

animals are typically uncooperative
- delivery deep into the pharynx triggered reflex swallowing and delivery into the rumen

Question 22

What are the benefits of injection formulation for animals? What are the types available?

Answer 22

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

Question 23

What drugs can be administered to animals via food?

Answer 23

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

Question 24

What drugs can be administered to animals topically?

Answer 24

frontline
- is applied topically over fur

• is fast and low stress but is less precise than injections

Question 25

What is a veterinary solid dosage form known as? What are the issues associated?

Answer 25

bolus
- rumen release may be slow