PK1-formulations +requirements of parenteral medicines

what is the parenteral route 

• method of delivering drugs directly into the body by bypassing the GI tract entirely 

what are the advantages of parenteral formualations 

what are the disadvantages of parenteral formulations 

what are the general requirments of parenterals 

• they must be sterile

• they must be free from endotoxins and pyrogens as they can cause fever and shock 

• some parenterals mostly iv there musnt be any particulates/minimal so suspensions cant be given IV as they can accumilate. and for iv droplets they must be small 

how does the solubility affect how a parenteral can be given 

good solubility= solution 
moderate=solution with co-solvents or a suspension 
low=suspension not IV 

what are the requirments of IV SC,IM/ what drug forms can they be given as 

IV-they must be aqeous solutions that must not precipitate in the blood stream 
they can also be emulsions if the particle size is small. the drug can be given as a large volume 
IM + SC- they can be given as suspensions,solutions and emulsions 

what are the excipients usually added into parenteral formulations 

• co-solvents 

• buffers

• surfactants 

• anti-oxidants 

• preservatives

• tonicity agents 

what is tonicity 

its a measure of how an extracellular solution can cause a cell to gain or lose water through osmosis 

what are the three types of  properties  a substance can have

what is vapour pressure depression 

• its the decrease in vapor pressure of a liquid when a non-volatile substance ( one that does easily evaporate) is dissolved into it 

• the more solute the less vapour pressure 

describe boiling point elevation and freezing point depression 

• when solute is added to a solvent the boiling point increases and the freezing point decreases as the vapour pressure has been dropped below the liquid 

what is osmotic pressure 

its the minimum pressure needed to stop a fluid from flowing across a semipermeable membrane into a more concentrated solution ( pressure needed to stop osmosis )

how is osmotic pressure measured in practice

osmoles ( Osm) or milliosmoles ( mOsm)

whats the definition of one osmole 

whats the difference between osmolarity and osmolality 

what are the clinical effects of cells being hyperosmotic 

what are the clinical effects of cells being hypoosmotic 

whats the difference between isotonic solutions and isosmotic 

isotonic-the solutions are seperated by a biological membrane whereas isosmotic the solutions are seperated by a perfect semi-permeable membrane 
in both theres no net movment