Parenterals Flashcards
Parenteral
- Intended to be placed in direct contact with the internal body fluids or tissues (injections)
- Must be sterile and pyrogen-free
Sterile
Absence of viable microorganisms
Sterilization
Process by which all viable microorganisms are removed or destroyed
Pyrogens
- Bacterial endotoxins
- Organic substances resulting microbial growth or breakdown
- Produces fevers, chills, malaise, shock when injected into humans
Injectables
Any dosage form placed beneath the skin of the body using a needle, catheter, or cannula
Thrombus
Blood clot formed within a blood vessel
Embolus
Thrombus that is circulating in blood stream
Embolism
Embolus lodges in a blood vessel and blocks or occludes blood flow
When to Use Parenterals
- Rapid onset of action (general)
- Patient is uncooperative
- Patient is unconscious
- Drug not absorbed through biological membranes (compare oral tablets)
Routes of Parenteral Administration
- Intramuscular - 90 degrees
- Subcutaneous - 45 degrees (subcutaneous tissue)
- Intravenous - 25 degrees (dermis)
- Intradermal - 10-15 degrees (epidermis)
IV Advantages
- Rapid onset of action - no absorption step
- Accurate blood levels can be achieved and maintained by continuous infusion of drug
- Useful in emergency situations because of the rapid circulation of the drug
IV Disadvantages
- Once administered, drug cannot be retrieved
- Potential for thrombosis or embolism - most common if needle touches wall of vein
- More common when drug solution is irritating to body tissue
Bevel
- Inject with needle facing upwards at an angle
- Ensure direction of flow is in flow with the blood
- Ensure that lumen is unobstructed
Flashback/Back Flow
Pulling back on syringe to ensure entrance into vein, blood should enter syringe if in vein
Aseptic Precaution
- Used to avoid risk of infection
- IV solution, syringe, and needle are sterile
- Swab skin area to clean prior to injection
Vessels
- Differ in size and closeness to surface
- Differ with age, type of illness, gender
- Men’s are closer to surface than womens’
Are injections more or less painful near fingers?
More
Should you administer irritating drugs in larger or smaller veins?
Larger - want the maximum chance of immediate dilution
What can be administered by IV?
- Large and small volume parenterals (no volume restriction)
- Drugs must be in solution - water or water-miscible solvent, emulsions (NO SUSPENSIONS OR OIL SOLUTIONS)
- Can use almost any size needle depending on injection site
IM Advantages
-Prolonged drug action compared to IV (depot effect)
IM Disadvantages
- Longer/larger needles needed
- Less rapid onset
- Absorption steps - muscle to blood stream which can be fast or slow depending on formulation
IM Route - Sites
- Avoid major nerves and blood vessels
- Upper quadrant of butt
- Thigh (vastus lateralis) or deltoid of arm are also good sites
- Thigh or deltoid are best for infants/small children (not enough muscle in gluteus maximus)
Should there be flashback/backflow of blood with IM?
No
What can be administered by IM?
- Aqueous solutions/suspensions
- Oleaginous solutions/suspensions
- Chemical/physical properties of drug and anticipated biological response determines which prep to use
- Solutions with water-miscible solvents are rarely used IM since they tend to cause irritation/damage
- Volume restrictions - 2 mL for deltoid; 5 mL for butt
SC Info
- Injection just under skin - loose interstitial tissue of upper arm, anterior thigh, or lower abdomen
- Shorter, more narrow gauge needles used
- No flashback/backflow
- Absorption step - rates can be rapid depending on formulation
- Aqueous solutions and suspensions
- Volume restriction - ~1.3 mL
ID (Intradermal) Info
- Injection just beneath epidermis
- Least common
- Typically for immunizations, diagnostics (TB), or anesthetics for pain during stitching procedures
- Short needles or narrow gauges
- VERY small injection volumes
ID Sites
- Upper pectorals
- Back near shoulder blades
- In the bends of elbows
Other Routes of Admin
- Intra-articular (joints)
- Intrasynovial (joint fluid area)
- Intraspinal (spinal column)
- Intrathercal (spincal fluid)
- Intra-arterial (arteries)
- Intracardiac (heart)
- Central venous catheters (ports) - used when repeated IVs are required like in chemo patients or TPN solutions
Parenteral Formulaiton Requirements
- Solvents/vehicles must be of highest purity
- Added substances must be of highest purity
- Inclusion of each material MUST be justified
- ALWAYS sterile and pyrogen-free
- Stricter compendial standards for the limits of particulate matter
- Prepared STRICTLY in controlled environments by trained personnel
- Packaged in HERMETICALLY sealed containers of high quality
- Filled to a volume that is in excess of the labeled size
- Restrictions limit the volume of the product which can be sealed into a container
- Specific label requirements
Parenteral Solvent Vehicles
Aqueous Vehicles
- Water for injection
- Sterile water for injection
- Bacteriostatic water for injection
- Sodium chloride injection
- Bacteriostatic sodium chloride injection
- Ringer and lactated ringer injected
Non-Aqueous Vehicles
Water for Injection, USP
- Purified by distillation or reverse osmosis
- Total solids <1mg/100 mL
- May contain added substances
- Must be pyrogen-free (not required to be sterile)
- Intended to be used in the manufacture or injectable products`
Sterile Water for Injection, USP
- Packaged in single-dose containers, no larger than 1 L
- Must be pyrogen-free (and sterile)
- Cannot contain any antimicrobial agents or other substances
- Intended to be used a solvent, vehicle, or diluent for already sterilized and packaged injectables
- 1 L bottle cannot be administered intravenously due to lack of ISOTONICITY
Bacteriostatic Water for Injection, USP
- Sterile water for injection containing one or more antimicrobial agents
- Packaged in prefilled syringes or vials (=< 30 mL)
- Used as a sterile vehicle in preparation of small volume parenterals (< 5mL of solvent is needed)
- Labeled “not for use in neonates”
Sodium Chloride Injection
- Sterile isotonic solution of sodium chloride in water for injection
- No antimicrobial agents
- Used as sterile vehicle in solutions or suspension of drugs for parenteral admin. (reconstitution)
- Also used to flush catheter/IV line
Bacteriostatic Sodium Chloride for Injection
- Sterile isotonic solution of sodium chloride in water for injection + one or more antimicrobial agents
- Packaged in vials =< 30 mL
- Used for reconstitution and to flush catheter/IV line
- Not for use in neonates
Ringers Injection
- Sterile solution of sodium chloride, potassium chloride, calcium chloride, and sodium bicarbonate in water for injection
- Concentration of electrolytes similar to physiologic fluids
- Used as vehicle for other drugs or alone as an electrolyte replenisher and plasma volume expander
Lactated Ringers Injection
- Different concentrations of the 3 salts plus sodium lactate instead of sodium bicarbonate
- Used as a fluid and electrolyte replenisher and a system alkalizer
Non-Aqueous Vehicles
- Used when physical and chemical characteristics of drugs preclude the use of water
- Solvents include water-miscible and not water-miscible
- No single “miracle” non-aqueous solvent
Water-Miscible Solvent Examples
- Propylene glycol
- Polyethylene glycol
- Glycerin
- Alcohols
Not Water-Miscible Solvent Examples
- Peanut oil
- Cottonseed oil
- Sesame oil
- Castor oil
DO NOT USE MINERAL OIL
Other Substances
- Only included if they increase stability or usefulness of preparation
- For some drugs, which substances CAN NOT be included are in their monograph
- Typical additives: buffers, preservatives, solubilizers, and antioxidants
Possible Ingredient List
- Drug
- Solvent
- Osmotic pressure adjuster
- Bacteriostatic agent(s)
- Buffers
- pH Adjusters
- Antioxidants
- Chelating Agents (EDTA)
- Solubilizing Agents
- Viscosity Building Agent
Osmotic Pressure Adjusters
- Added if needing to achieve a desired osmotic pressure
- EX: NaCl, Mannitol, dextrose
Bacteriostatic Agent(s)
- Used if multi-dose product
- EX: benzyl alcohol, phenol
Buffering Agents
- Only added if pH range is necessary to maintain
- EX: phosphate salts, acetates, citrates
pH Adjusters
- If product requires specific pH
- EX: NaOH, HCl
Antioxidants
- If drug is prone to oxidation
- EX: Bisulfate, ascorbate
Solubilizing Agent
-If needed to get desired concentration of drug
EX: surfactants like polysorbate 80
Viscosity Building Agent
- IF suspension product used
- Thickener
- EX: NaCMC
Sterility and Pyrogens
- Complete destruction or removal of all living organisms and their spores form a preparation
- Several sterilization methods utilized
- Method Used depends on ingredients/prudct
Sterilization Methods
- Steam Sterilization
- Dry-heat sterilization
- Sterilization by filtration
- Gas sterilization
- Sterilization by ionizing radiation
Steam Sterilization
- Requires an autoclave (similar to pressure cooker)
- Bacteria and spored are killed by high pressure steam, permeates everything
- Sealed vials or ampules (flass) or an aqueous solution will generate their own steam at high temperatures and sterilize inner contents
- Destruction of the protein in the cell kills microorganisms
- Higher pressures allow for higher temperatures to be achieved and therefore less exposure periods to be necessary
Dry-Heat Sterilization
-Form of sterilization that uses ONLY heat
-Kills bacteria/spores by dehydration
-Requires higher temperatures and longer exposures than steam sterilization
(160-170C for at least 2 hours)
-Many drugs/products can’t handle these temperatures
-Dosage forms that can handle it: oil-based suspensions/solutions, petrolatum products, bulk powders
Filtration Sterilization
- Physical removal of microorganisms by passing solutions through specialized filters
- Cellulose is the most common, or nylon
- High number of narrow pores through a tortuous path
- Primarily used for heat sensitive products
- Cannot be used for suspensions
- Filters used in multiple places during manufacturing
- Often used in clinics/hospitals when small amount of solution needs sterilization
- Can be fast/efficient with small volumes but takes more time with larger volumes or highly viscous products
- Prepackaged filter/filter holders can be used for single use
- Suitable for thermo-labile drugs
- Possibility of active drug absorbing to the membrane filter
Filter Sizes
- Generally 0.22 and 0.45 micron
- 0.45 - gives clean particulate-free solution but only when starting with sterile solution
- 0.22 when combined with clean, top-quality ingredients and sterile water is usually considered to produce a sterile solution
- CANNOT STERILIZE SOLUTIONS WITH VIRAL EXPOSURE
Gas Filtration
- Exposure of product to ethylene oxide or propylene oxide gas
- Gases interfere with metabolism of microorganisms
- Method requires a chamber (like an autoclave)
- Product exposed to gas, humidity, and heat
- Exposure time: 4-16 hours depending on product/conditions
- Primarily used to sterilize surgical instruments, needles, syringes, and disposable plastics
Ionizing Radiation Sterilization
- High energy, penetrating gamma radiation
- Can sterile even densely packaged products
- Microorganisms die and can no longer grow due to DNA damage
- Cold process with no heat
- Time of exposure is the only variable
- Can be used with devices, syringes, ointments, raw ingredients, heat-sensitive drugs
How to know a process worked?
- Validation of process - like manufacturing the active and drug product
- Test methods defined by USP
- Aerobic and anaerobic organisms killed is tested
- Tests are also performed routinely to confirm equipment’s functionality (autoclave tape for example)
Pyrogen-Free Establishment
- Ideally use pyrogen-free water, top ingredients, ensure no times for microorganism growth
- Pyrogen Test - inject healthy rabbits with 10 mL/kg of product and if <0.5 temperature increase is achieved then considered pyrogen free
- Bacterial Endotoxins Test - aka ‘LAL’ test (limulus amebocyte lysate), enzyme from horseshoe crab that will coagulate in the presence of bacterial endotoxins
Parenteral Storage/Packaging
- Compatibility of container with formulation
- Type of glass for storage may be indicated in the drug’s monographo
- Amber and clear glass - inspection of contents allowed
- Single dose: cannot be re-sealed
- Multi-dose: allows to remove some product while maintaining purity
Single-Dose Containers
- Ampules: sealed by fusion of glass container under aseptic conditions, break top, use filter needles
- Vials: liquids or powders for reconstitution
- Single-use, disposable, pre-filled syringes
Multiple Dose Containers
- Vials with rubber closures
- Holds =< 30 mL (~10 doses)
- Use needle to penetrate closure and remove desired volume, closure reseals upon removal of needle
- Sterility maintained as long as need is sterile
- Prefilled syringes also exist for multiple dosing
- Typically contain antibacterial preservatices
- Liquids or powders for reconstitution
Parenteral Labeling Requirements
- Name of prep
- Strength - liquids = % strength and amount/volume. powder = amount of active present
- Route of admin
- Storage conditions
- Lot number and expiration
- Name of manufacturer/distributor
- Label on container must allow for visual inspection
Small Volume Parenterals: Insulin
- Hormone secreted by pancreas-glucose metabolism
- Patient produces no insulin
- Insulin does not respond to body glucose
- Very high MW protein from pig/cow pancreas, also some human sources
- Primarily administered SC - too large to be absorbed orally and degraded by stomach acid/enzymes
Insulin Formulations
- Multiple dose vials or prefilled syringes
- Strength = units/mL
- Insulin differs by onset, time to peak, and duration of action
Insulin Injection
- Regular insulin (‘R’)
- Solution made form dissolved zinc-insulin crystals
- Near neutral pH
- Contains phenol or cresol as a preservative
- Rapid onset of action (immediate)
- Stored in fridge
- Should not be frozen (damages proteins)
- Don’t inject cold product
Isophane Insulin Suspension
- ‘NPH’ insulin
- eutral Protamine Hagedorn
- Aqueous, buffered suspension containing crystals of zinc-insulin-protamine
- Suspended particles ~30 microns in size
- Human or animal sources
- Intermediate acting
Mixtures of NPH/Regular Insulin
- Fast onset of action
- Longer duration
- Mixed together in syringe and injected
- Available in premixed vials
- 70/30 or 50/50 (NPH/Regular)
- SC only
Prompt Insulin Zinc Suspension
- Semilente
- Amorphous insulin zinc suspension
- Dissolves rapidly after SC injection
Extended Insulin Zinc Suspension
- Ultralente
- Crystals of insulin zinc suspension
- Dissolves slowly upon SC injection
Insulin Zinc Suspension
- Lente
- 70/30 mixture of ultralente and semilente
- Fairly rapid onset, intermediate duration -Still possibly available for use in dogs and cats
Insulin Lispro Injection
- Differs by a few amino acids
- Very rapid onset of action and short duration (multiple injections)
- Intended for injection just prior to a meal
- Lispro mixtures: complex with NPH to make it long acting in 75/25 or 50/50 mix
Insulin Aspart
- Novolog
- Differs by a few amino acids
- Very rapid onset and short duration
Insulin Glargine
- Lantus
- Rearrangement of amino acids (long duration)
- Intended to provide basal coverage
- Very fine dispersion of microspheres
Insuline Glulisine
- Apidra
- Another manipulation of insulin protein
- Rapid onset of action, short duration
- Admin prior to meal
- Intended to use in patients that also use a long acting insulin
Insulin Detemir
- Levemir
- Another insulin analog
- No peak activity but long acting
- Provides basal levels of insulin
- Other rapid acting/short duration insulin used to provide extra activity for meals
Insulin Infusion Pumps
- Infusion of SC insulin to maintain normal levels - strict control at 70-140 mg/dL
- Small, lightweight pumps
- Delivers either short-acting or rapid-acting insulin
- Patients still need to monitor glucose levels
- Potential infusion-site reactions
- Can be used in conjunction with artificial pancreas
Administering Insulin Pen
- Pen holds multiple doses of insulin
- Small disposable needle tips attached
- Inject SC
- Can be pre-filled that are discarded when empty or reusable by adding new cartridges
Large Volume Parenterals
- 100-2000 mL
- Glass bottles or plastic bags
- Lack of preservatives so single use
- Not necessarily drug-containing solutions
- If adding a drug there is a possible incompatibility
- Given by IV
- Same quality criteria as small volume parenterals - sterile and pyrogen-free
Use of Large Volume Parenterals
- Maintenance
- Replacement therapy (water, electrolytes)
- Deliver calories
- Enable slow infusion of drug solutions - contrast to single bolus
- Parenteral nutrition
Parenteral Special Considerations
- Potential for med errors from calculation mistakes or wrong drugs
- Adsorption of drugs in the IV lines, glassware, or tubing
- Contamination of IV lines and tubing
- Handling and disposal of chemotherapeutics
Implantable Pellets
- Alternative injectable
- EX: Levonorgestrel implants
- Subdermal implantation
- Provides long-term reversible contraception
- Must be sterile and pyrogen-free
Irrigation Solutions
- Alternative injectable
- Bathe/wash wounds, surgical incisions, body tissues
- Must be sterile and pyrogen-free
Dialysis Solutions
- Alternative injectable
- Remove toxins from blood (hemodialysis)
- Removes toxins from peritoneal cavity (peritoneal dialysis)
- Must be sterile and pyrogen-free