MOD 7 - COURSE 3 - PT 1 - GENERAL PRINCIPLES OF GOOD RPACTICES

Question 1

what does the brest rpactice of proceudres of animl research

Answer 1

• minimise or avoiding adverese effects - refinement
• minimise number of aniamls used - i.e. reduction
• maximise the qua;lity the quality and applicability of results

Question 2

how do you choise the route

Answer 2

• determined by purpose of experiemnt -s pecies of aniamsl and possible effects of doing technique of animal and expected rfequency of dosingmore stessful - least ssever while still agreeing with experiment aims
  so need to consider:
• EXPERIMETNAL AIMS
• TECHNICAL SKILL
• EFFECT TO ANIAML

Question 3

What needs to be taken into consideration for the effect on animals

Answer 3

• habituate and train aniamls for procedures -
• consider ananesthetic/sedative
• aniamls = monitored
• repeated dosing/sampling - should be carried out same time - avoid variability with circadian shythms
• necessary resitct aniamsl food intake before dosing - if fasting = required peoiod of food depravations = limited to meat scientific aimals

Question 4

what is a circadian rhythm

Answer 4

• 24 hour cycle - endogenously generatied - modulated by external cause i.e. sunlight adn temp
• present in sleepina dn feeding pattern of anaimsl - clear patters of core temps, brain activity, hromone production, cell regernation other activities

Question 5

how does a circadian rhythm affect fascting conditions

Answer 5

• depends on feeding aptern of species - starting time for food restriction and physiology o spceis - legnth of dosing time an dlight cycle
• dependsing for scientific questions -
• metabolic rate changes at time of fay
• mice and rats = 70% clalory intake at night - so overnight fast = more akin to starvation

Question 6

what are some physiochemcial properties of drugs to consdier

Answer 6

• pH
• solubility
• biocompatibility
• sterility
• temperature

Question 7

why do we have to measure pH of a drug/compound

Answer 7

• • indicator papper - should be physiological pH

Question 8

why do we have to consdier solubility fo a substance

Answer 8

• poorly soluble drug - may fall out of solution at injection site - affecting its properties
• can use an invitro solubility test - for itnraveoun compatibility - the higher the LD50 = more compatible of RBC with drug

Question 9

why do we have toc consider biocompatibility o f a drug

Answer 9

• substance - in ocntacnt with living system without adverese effects
• if not compatible = tissue damage
• intvitro technique s- identify afverse effects - haemolytic - rupture of RBC

Question 10

why is important for drug to be sterile

Answer 10

contamination - cause infection and irritated
- use aseptic tehcnqiue
- autoclave or filtration trhough 0.22mm dilter

Question 11

why is te temeprature of the drug imporatnt

Answer 11

• cold substance injectionn - dicomford - hypothermic shock - when larg evolume
  so warm substances

Question 12

what are some classical solvents used for drugs

Answer 12

• PBS
• WATER
• DMSO

Question 13

why is pBS used

Answer 13

• water salt solutoin - sodium phosphae, sodium chloride, potassium chloride, postassium phosphate
  =0 isotonic - non toxic

Question 14

why is water used

Answer 14

• use fro oral and rectal enteral administaration
• if injection - must be commercial water for injections
• so not use os IV - unless adjusted to approx isotonicity with suitable solute - since ehmolysis -can occur otherwise
• injected SC - casue pain

Question 15

why is DMSO used

Answer 15

• antioxidant - so soluble in both AQ and organic emedia
• so more drugs ca be used in it
• for enteral or parenteral administration
• concentraiton = less than 10%
• effect of DMSO - on metabolsum and toxicity of drugs = reported