(7) Parenteral Systems 1 + 2 Flashcards
(21 cards)
how do you classify between small volume parenteral and large volume parenteral?
- Small volume Parenterals (SVP) (100ml or less)
- Large volume Parenterals (LVP) (up to 500ml)
list some advantages of parenteral administration?
- Local effects can be achieved where desirable –
anesthesiology - Formulations can permit prolonged drug release
profiles
Depot injections
Long-acting steroids
Long-acting penicillins by deep IM injection - Provides a means of correcting serious disturbances
of fluid and electrolytes - When food cannot be swallowed or taken orally, total
parenteral nutrition can be tailored to meet the
individuals exact nutritional needs
outline water for injection.
- Clear, colourless and odourless (pH 5 - 7)
- Purity specifications limit
- Cl-, Ca2+, SO42-, NH3, CO2, heavy metals and oxidisible substances total amount of dissolved solids < 10 ppm
- Must be used within 24h unless sterilised, sealed in
ampoules or containers
what % gram moleular concentration is an isotonic solution?
0.0003
what are disadvantages of parenteral administration?
- Requires aseptic technique
- Skill of administration required
- Pain on administration
- Rapid development of allergic reactions in sensitive individuals
- Difficult to reverse effects of drugs given parenterally, even immediately after administration
- Inherent requirements (sterility, freedom from particulate matter & pyrogens, stability) requires understanding from all personnel who manufacture or administer the formulation
what are requirements of large volume parenterals?
- Sterile
- Non-pyrogenic
- Free of Particulate Matter
- Packaged as single dose containers
what injections should preservatives not be added to?
- Intrathecal, intracisternal and peridural (epidural) use (CSF injection)
- Intracardiac or intraocular injections
- Injections in which a single dose is greater than 15mL,
unless the BP monograph specifically allows the presence of a preservative
what is a colligative property?
When a non-volatile solute is dissolved in a solvent certain
properties of the resultant solution are largely independent
of the nature of the solute and are determined by the
concentration of the solute. Most important one for pharmaceutical pot is osmotic pressure
what is a hypertonic solution?
- in a hypertonic solution (osmotic pressure greater than blood
serum), water will pass out of the cell - the cell shrinks and the cell wall appears crenulated
What is a hypotonic solution?
- In a hypotonic solution (osmotic pressure less than blood serum), water will pass into the cell until equilibrium is established
- the cell swells rapidly and bursts
What is a preservative?
Antimicrobial preservative agents serve to maintain sterility of the product during shelf life and use
what is a pyrogen?
a substance that induces fever - they are derived mainly from gram negative bacteria
what is an isotonic solution?
- Solution where the osmotic pressure is the same as the blood serum
- This is what all parenteral systems need to be
what is the intradermal route?
- drug injected into superficial layer of skin
- absorption is slow
- generally reserved for diagnostic tests
- small volumes around 0.1 - 0.2mL
what is the intramuscular route?
- Volume circa 2 mL (up to 5 mL gluteal administration)
- Typical sites include the shoulder (deltoid), thigh and buttock (gluteal medials)
- Very suitable for aqueous and oily solutions and suspensions which are irritant by the SC route
- More rapid absorption than SC - can be modified by formulation type (oily liquid, suspension etc.)
What is the intravenous route?
- Large or small volumes (up to 500mL) can be administered to the veins for rapid effect
- Formulations relatively simple - active drug, other ingredients (TPN components, preservatives etc.) and a solvent system (preferably aqueous)
- Results are rapid and predictable but potentially dangerous (no retreat following administration)
- Irritant drugs rapidly diluted in blood
- Number & location of vein = accessibility
what is the osmotic pressure?
Simply the minimum pressure needed to prevent osmosis.
- The force per unit area, or pressure, required to prevent the passage of water through a selectively permeable membrane
and into a solution of greater concentration is equivalent to the osmotic pressure of the solution
what is the subcutaneous route?
- Drug injected into loose subcutaneous tissue beneath skin
- Volume circa 1 mL
- Usually administered in the upper arm or thigh
- Popular route of administration (e.g. insulin)
- More rapid onset of action than intradermal
whats the acceptable range of pH?
36991
whats the difference between enteral and parenteral?
enteral = administered via the gut
Parenteral = administered by bypassing the gut
whats the difference between suspensions and emulsions?
suspension = dispersion of drug in one continuous phase
Emulsion = disperse systems in which one immiscible liquid is dispersed in the other
