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Chapter 7 notes
Chapter 7 Routes and Formulations
Question | Answer |
---|---|
The way in which the body absorbs and distributes drugs varies with what? | the route of administration and the dosage form used |
Enteral or Parenteral | Routes of administration |
Any route other than oral, sublingual, buccal or rectal is considered a | Parenteral route of administration |
Parenteral | Next to, or beside the enteral. Refers to any sites of administration that are outside of or beside the alimentary tract |
for each route of administration | there are various formulations used to deliver the drug via that route |
Different dosage forms | affect onset times, duration of action or concentrations of a drug in the body |
a consideration for selecting a particular route of administration or dosage form is | the type of effect desired |
Local effect | occurs when the drug activity is at the site of administration (eg. eyes,ears,nose,skin) |
systemic effect | occurs when the drug is introduced into the circulatory system from the route of administration and carried by the blood to the site of the activity |
List the 4 enteral routes | Oral, sublingual, buccal, rectal |
Dosage forms for oral | Tablets, capsules, bulk powders, solutions, suspensions, elixirs, syrups,emulsions |
Dosage forms for buccal | Tablets, solutions |
dosage forms for sublingual | Tablets, lozenges |
dosage form for rectal | solutions, ointments, suppositories |
List 7 parenteral routes | Intraocular, intranasal, inhalation, intravenous, intramuscular, intradermal, dermal |
dosage forms for intraocular | Solutions, suspensions, ointments, inserts |
dosage forms for intranasal | Solutions, suspensions, ointments, gels |
dosage forms for inhalation | solutions, aerosols, powders |
dosage forms for intravenous, intramuscular, intradermal | Solutions, suspensions, colloids, emulsions |
Dosage forms for dermal | Solutions, tinctures, collodions, linimints, suspensions, ointments, creams, gels, lotions, pastes, plasters, powders, aerosols, transdermal patches |
intraocular | eye |
intranasal | nose |
buccal | inside the cheek |
sublingual | under the tongue |
dermal | through or on the skin |
inhalation | lungs |
oral | stomach or intestines |
intravenous | venous circulatory system |
intradermal | dermal layer of skin |
vaginal | vagina |
rectal | rectum |
subcutaneous | subcutaneous |
intramuscular | muscle |
Subcutaneous dosage form | solutions, suspensions, emulsions, implants |
vaginal dosage form | solutions, ointments, cream, aerosol foams, powders, suppositories, tablets, IUDs |
Oral administration is the most | frequently used route administration |
oral dosage forms are easy | to use and administer |
PO means by mouth which came from the term Peroral which means | the dosage will be swallowed and the absorption will be primarily from the stomach and the intestine |
the stomach is very acidic and has a PH of | 1-2 |
certain drugs cannot b taken orally because | they are degraded or destroyed by stomach acid and intestinal enzymes |
degraded | chemically changed to a less effective form |
the absorption of many drugs is affected by | the presence of food in the stomach |
Drugs administered in liquid dosage forms generally reach the circulatory system faster than drug formulated in solid dosage forms. this is because | disintergration and dissolution are not required |
oral liquids include | solutions, suspensions, gels and emulsions |
solid dosage forms include | tablets, capsules, and bulk powders |
PH | the ph scale measures acidity or alkalinity of a substance. |
ph of 7 represent | neutral |
ph of 1-6 represent | increasing acidity |
ph of 8-14 | increasing alkaline, base |
inactive ingredients in medicines include | binder, lubricants, fillers, diluents, disintegrants |
Why are inactive ingredient like Binders, fillers, lubricants, diluents, etc. used in medicines? | to help the dosage form disintegrate and dissolve when administered |
PH of small intestine | 6-7 |
PH of large intestine | 7-8 |
the disintegration and dissolution of tablets, capsules and powders generally begins to occur in | the stomach but will continue to occur when the contents of the stomach empty into the intestine |
Enteric coated tablets are used when | the drug can be degraded by the stomach acid |
What does the enteric coating enable the tablet to do? | wait until it reaches a higher level of PH in the intestine before it disintergrates |
Disintegration | the breaking part of a tablet into smaller pieces |
dissolution | when the smaller pieces of a disintegrated tablet dissolve in solution |
Tablets are | hard formulations in which the drug and other ingredients are machine compressed under high pressure to form into shape. |
depending on their intended use tablets vary in | size, weight, hardness, thickness, disintegration and dissolution characteristics |
Multiple compressed tablets contain | one drug in an inner layer and another drug(or the same drug) compressed at a lower pressure around it as an outer layer |
a multiple compressed layer can also have | 2 layers adjacent to eachother |
Repeat action tablets | initially release one dose of the drug and then release a second dose some time later |
types of tablets | sugar coated, film coated, multiple compressed, repeat action, chewable, and effervescent |
Capsules contain | the drug and other ingredients are packaged in a gelatin shell. |
what is the capsule size based on? | the amount of material to be placed in the capsule |
what does the capsule do once taken | the gelatin shell dissolves in the stomach and the medicine is released. then it undergoes disintegration and dissolution before the drug is dissolved into the circulatory system |
Soft or Soft gel capsules | contain liquid instead of powders in a gelatin shell. the active drug is already dissolved in liquid |
Bulk powders | contain the active drug in a small paper or foil envelope. The patient empties the contents of paper or envelope into water or juice and drinks the contents. Most of the drug and ingredients dissolve before the patients drinks it |
Modified release drug products | several oral formulations that release a drug so that a longer duration of action is achieved compared to conventional tablets |
what is the goal of modified release drugs? | to reduce the number of doses a patient needs to take during the day |
SR | sustained release |
SA | sustained action |
ER or XR | Extended release |
PA | prolonged action |
CR | controlled release |
TR | time release |
LA | long acting |
Solution | A clear liquid (not ness. colorless) made up of one or more ingredients dissolved in a solvent |
solvent | a liquid that can dissolve another substance to form a solution |
Aqueous solution | most common oral solution. means water was used as the solvent |
types of solvents | water, alcohol, glycerin, propylene glycol or any combo of these |
Syrups | Concentrated or nearly saturated solutions of sucrose in water. more viscous than water, contains less than 10% alcohol |
flavoring syrups | syrups containing flavoring agents |
medicinal syrups | contain drugs ie. guaifenesin syrup |
Nonaqueous solutions | solutions which predominantly contain solvents other than water either alone or in addition to water |
Nonaqueous solvents | alcohol, glycerin, and propylene glycol |
Elixirs | clear, sweetened, hydroalcoholic liquids intended for oral use. can either contain alcohol soluble or water soluble drugs. |
Elixirs are usually | less viscous and less sweet than syrups |
alcoholic content of elixirs is | between 5%-40% alcohol or 10-80 proof |
Spirits or essence | are alcoholic or hydroalcoholic solutions of volatile substances, |
alcoholic content of Spirits or essence | between 62%-85% or 124-170 proof |
Sprits or essences are mainly used | as flavoring agents, some spirits ae used for medicinal effect |
Tinctures | are alcoholic or hydroalcoholic solutions of nonvolatile substances. |
Tinctures of potent drugs have how many grams of the drug per 100ml? | 10g they are called 10% tinctures |
Tincture of nonpotent tinctures generally have how many grams per 100ml of tincture? | 20g |
Suspensions | formulations in which the drug does not completely dissolve in the solvent. the drug particles are suspended in the formula. sweetened and flavored |
primary concern in formulating suspensions | they tend to settle over time leading to a lack of dose uniformity. a well formulated suspension will remain suspended or settle very slowly and can easily be redispersed with shaking |
Some commercial suspensions are packaged as | lyophilized powder. |
Reconstitution | when water is added to lyophilized powder in a container and a suspension is made |
Advantages of solutions | -completely homogenous doses, immediately available for absorption, for patients who cant swallow pills, doses can be easily adjusted |
Disadvantages of solutions | drugs and chemicals are less stable in solution than dry dose, some drugs are not soluble in solvents that are acceptable for therapeutic use, may require special additives or techniques to mask objectionable taste, difficult to handle, transport + store |
Advantages of suspension | Can orally administer drugs that are insoluble in acceptable solvents, can be taken or administered when cant swallow,masks objectionable taste, drug are chemically more stable than in solution |
Disadvantages of Suspension | tend to settle over time leading to lack of dose uniformity, unpleasant oral texture |
emulsions | some formulations contain both aqueous and oleaginous components. These two can be formulated into n homogenous mixture when and emulsifying agent is used |
oleaginous | oil based |
Emulsifier | enable one of the components to be dispensed in the other in the form of little tiny globules or droplets |
If the oleaginous component is present as droplets | the emulsion is called an oil in water (o/w) emulsion |
if the aqueous component is present as droplets | the emulsion is called water in oil (w/o) emulsion |
Emulsions are used in many routes of administration. which route do patients complain about the oily feel? | Oral |
Why would an emulsion be the formula of choice? | To mask the taste of a very bitter drug, or when the oral solubility or bioavailability of a drug is to be dramatically inceased |
How can you find an emulsion in the topical form? | As a cream, lotion, or ointment base |
Emulsions used for oral administration are: | physically unstable and tend to separate into two distinct phases over time. |
When does creaming with an emulsion occur? | when dispersed droplets merge and rise to the top or fall to the bottom of the emulsion. |
A creamed emulsion can easily be redispersed by | shaking. Coalescence is the irreversible separation of the dispersed phase. |
Coalescence | Breaking or cracking |
What substances are Gels made from | Gelling agents that the increase viscosity (thickness)of the liquid in which they are placed |
Gelling agents form | an interlacing three dimensional network of particles that restricts the movement of the solvent |
Common known gelling agents | Acacia, Alginic acid, Carbopols (carbomers), gelatin, methylcellulose, tragacanth, xanthan gum |
Even though each gelling agent has some unique properties, there are some generalizations that can be made. | Most GA require 12-24 hrs to reach max viscosity and clarity, GA are used in concentrations of .5% up to 10% depending on the agent, its easier to add the active drug before the gel has formed, only some are recommended for oral administrtion |
The only gels recommended for oral administration | Carbopol 934P, methycellulose, hydroxypropylmethylcellulose, and sodium caboxymethylcellulose |
An emulsion is | a mixture of two liquids that do not mix with eachother in which one liquid is dispersed through the other by using a stabilizer called an emulsifier |
When rapid action is desired what route of administration is preferred? | The mouth- Buccal or Sublingual |
formulations used in the mouth are usually: | Fast dissolving, uncoated tablets which contain highly water soluble drugs |
When a tablet is placed under the tongue, what kind of administration is that? | Sublingual |
When a tablet is placed into the cheek to dissolve, what kind of administration is that? | Buccal |
In a SL administration, when the drug is released from the tablet, it is quickly absorbed into what system? | the circulatory system, since the membranes lining the mouth are very thin and there is rich a blood supply to the mouth |
What medication is the best example of a sublingual administrated tablet formation? | Nitroglycerin |
Where is Nitroglycerin degraded in the body after being taken SL? | degraded in the stomach and intestines |
Another type of administration for Nitroglycerin is | a translingual aerosol that permits a patient to spray droplets under the tongue |
Because of the bitter taste of holding tblets under the tongue, what other SL form of administrion can be used? | Lozenges, which are generally formed with sweetening agents |
Why is the buccal cavity used? | It allows for rapid absorption of drugs and bypasses first pass metabolism in the liver |
Sub, Trans, and lingua are Latin words meaning | Under, across or over and tongue. |
Water soluble | the property of a substance being able to dissolve in water |
Steps in using a SL tablet | 1. Take a sip of water 2. pleace tab under tongue 3. mouth must remain closed until the tab is dissolved and absorbed. |
why would drugs be administered rectally? | For a local effect or to avoid degradation after oral administration |
Local effects from a rectal administration | Soothing inflamed hemmorhoids or promoting laxation |
Rectal administration is preferred when | the drug is degraded by stomach acid or intestinal enzymes, or if oral administration is unavailable. |
Systemic effects of rectal administration | Asthma control, antinausea, motion sicknes and anti infective therpy |
Most common rectal forms of administration | Suppositories, solutions, and ointments |
Suppositories are | a semisolid dosage form that dissolves or melts when inserted |
Suppositories are manufactured in many shapes, and are used in other routes of administration like | vaginal or urethral |
Rectal ointments are intended to be | spread round the anal opening and are most often used to treat inflamed hemorrhoidal tissue |
Disadvantages of rectal doses | Not preferred by patients, inconvenient, rectal absorption of most drugs is frequently erratic and unpredictable |
Enemas | can create an urge to deficate due to the placement of fluid into the rectum. |
types of enemas | cleansing enema uses water or cleaning solution, retention enema uses an oil |
hemorrhoid | painful swollen veins in the anal rectal area, generally caused by strained bowel movements from hard stools |
Parenteral routes of administration that are injection independent | ophthalmic, intranasal, inhalation, dermal, vaginal, otic |
Parenteral routes of administration that are injection dependent | intravenous, intramuscular, intradermal, subcutaneous, epidural, intrathecal |
A parenteral route may be indicated when | an orally administered drug is poorly absorbed or is degraded by stomach acid or intestinal enzymes |
A parenteral route of administration comes in handy when | When a patient is uncooperative or unconscious or otherwise unable to take a drug. |
Disadvantages to parenteral routes of administration | Many are more expensive than enteral route formulations, many require skilled personnel to administer them, once a parenteral drug is administered, it is difficult to remove the dosage if there is an adverse or toxic reaction |
name 2 types of risks associated with parenteral administration of dosages with a needle | infection, thrombus |
What is a requirement for some types of parenteral administration? | a needle and some type of propelling device such as a syringe or pump to administer the drug |
Several characteristics that injectable routes have in common | formulations limited to solutions,suspensions and emulsions. Formulation must be sterile. Formula PH must also be carefully maintained, limited volumes of the formula can be injected |
Sterile | Bacteria free |
How is the PH of formulas carefully maintained? | Commonly done by adding ingredients to the formulation called buffer system. |
What happens if too much volume of the formulation is injected | pain and increased cell death |
necrosis | increased cell death |
Where are intravenous injections located? | directly into the veins and therefor into the circulating blood |
Types of IV injections | large volume, slow infusions with aqueous solutions such as D5W, or NS, small volume single injections, fat emulsions, blood tranfusions and patient controlled analgesia solutions |
NS | 0.9% sodium chloride in water |
PCA | Patient controlled analgesia |
1st layer of IV injection | epidermis |
2nd layer of IV injection | dermis |
3rd layer of IV injection | Subcutaneous |
4th layer of IV injection | vein |
5th layer of IV injection | Muscle |
Intramuscular injections are administered into | the muscle tisue |
IM injections generally result in | slower onset but longer duration of action compared to IV admin. |
Subcutaneous injections are administered where | the subcutaneous tissue |
SC administration provides | slower absorption than IM admin. and faster absorption than oral |
Intradermal injections are administered where | the top layer of skin, at a slight angle using short needles |
Most intradermal injection are used for what reason | mostly diagnostic determinations, desensitization or immunization |
buffer system | ingredients in a formulation designed to help control the PH |
How long does it take an IV administered drug to circulate throughout the body | 20 seconds |
What is the most common IV administration? | Solution. |
What types of solutions are there | most are aqueous, but they may have glycols, alcohols or other non aqueous solvents in them |
Why are injectable suspensions difficult to formulate? | They must possess suitable syringeability and injectability |
Syringeability | Refers to the ease with which the suspension can be drawn from a container into a syringe |
injectability | refers to the properties of the suspension while being injected, such as flow evenness, freedom from clogging, etc. |
What are fat emulsions for | Formulations used in TPN solutions to provide triglycerides, fatty acids and calories for patients who cannon absorb them from the gastrointestinal tract |
Dry powder formulations are manufactured for IV use, but what has to be done to them | they must be reconstituted with a suitable dilutent to make a liquid formulation |
what can be done to drugs that are not stable in liquid form? | lyophilized into a powder |
lyophilized | freeze dried |
What is a lyophilized powder reconstituted with | a solvent called a dilutent |
Common dilutents for IV formulas | Sterile water + bacteriostatic water |
IV site arm veins | 1. Basilic, 2. cephalic, 3. median cubital, 4. median ante- brachial |
IV site hand veins | 1. Cephalic 2. Dorsal venous arc 3. metacapal |
IV site Foot veins | Dorsalis pedis |
3 parts of a syringe | syringe plunger, syringe barrel, needle |
IV administration complications | Thrombus, phlebitis, air emboli, particulate material |
Why would blood clot be a problem with an IV injection site? | extreme in solution PH, particulate material, irritant properties,needle or catheter trauma, to small a vein for volume of solution |
Air Emboli occurs when | air is introduced into the vein |
particulate material can include | small glass chips from product vial or rubber pieces from vial closure, |
simple syringe and needle setups can be used to | inject formulations of a short period of time (generally up to 2 min.) |
What is syringe size based on | The volume of the formulation to inject |
What is the needle size based on | the route of administration being used (IV,IM,SC,ID) |
Infusion | the gradual process of IV injection of a volume of fluid into a patient |
What volume would a infusion generally be | a large volume - 500ml-1000ml |
Infusion solutions are generally an electrolyte solution such as | D5W or 1/2 NS |
1/2 NS | one half normal saline, .45% sodium chloride in water |
what is the rate of normal infusion? | 2ml-3ml per min |
What are the 2 ports on an infusion bag for? | An administration set port, a medication port |
What is the administration set port on an infusion bag for? | Provides the connection between the solution bag and the needle in the patient. May also be connected to an infusion pump to control the flow rate. |
What is the medication port on an infusion bag for? | where a simple syringe and needle may be used to inject a drug through the medication port into the solution bag |
What is a minibag? | A second small bag containing the drug that an be piggybacked onto the administration set through an infusion pump |
Infusion pump | an administration device to deliver medication through IV |
Why are infusion pumps dependent on gravity flow stopped being used? | They have variable delivery rate |
What are elastomeric pumps useful for | Very slow or continuous infusions |
What are elastomeric pumps? | Balloon like reservoirs filled with medication that is forced out of the reservoir through a flow restrictor |
IM injections are made are preformed where | into the muscle fibers that are under the subcutaneous layer of skin |
IM injection needles are generally how long | 1"- 1.5" |
What gauge needles are generally used for IM injections? | 19-22 gauge |
What are the principal injection sites of an IM injection? | Gluteus Maximus (butt), Deltoid (Upper Arm), and Vastus Lateralis muscles (thigh) |
When giving an IM injection into the gluteus maximus what is one thing to consider | The thickness of gluteal fat, particularly in female patients. |
If an appropriate sized needle isn't used when giving an IM injection into the gluteal fat of the gluteus maximus, what will happen? | The injection will not reach the muscle |
What should you know about the injection site for an IM injection | It should be as far away as possible from major nerves and blood vessels to avoid nerve damage and accidental intravenous administration |
Vastus Lateralis muscle | thigh muscle |
Injuries that could occur rom IM injections are | abscesses, cysts, embolism, hematoma. skin sloughing and scar formation |
To void injury when giving IM injections, what is recommended? | to rotate or change the injection site |
How many ML can be injected intramuscularly in deltoid and thigh? | 2ml |
how many ML can be injected intramuscularly in the gluteus maximus? | 5ml |
Does IM injection or IV administration usually result in lower but longer lasting blood concentrations? | IM injections |
What does the absorption step do for an IM injection? | Delays the time to peak concentration |
When a formulation is injected, what happens? | A depot is formed inside the muscle tissue where the drug is injected |
What factors into absorption from the depot | Muscle exercise,particle size of the drug, and the salt form of the drug used in the formulation |
Formulations for IM injections include | Solutions, suspensions, colloids, oil in water or water in oil emulsions |
what two formulations contain insoluble particles | Colloids and suspensions |
Which formulation has smaller particles, colloids or suspensions? | the particles in colloids are 100 times smaller |
Why are different salt forms of some drugs used? | to take advantage of a slower dissolution rate or a slower solubility. |
Why would you want to vary the amounts of particle size, the type of emulsion, and the salt form? | to achieve the desired absorption rate |
Which has a faster absorption rate, aqueous solutions or oleaginous solution? | Aqueous. both are faster than colloids or suspension. |
depot | area in the muscle where the formulation is injected during an IM injection |
Colloids | Particles of up to a hundred times smaller than those in suspensions that are, however, likewise suspended in a solution. |
What is a Z tract injection and why is it used? | A technique used for medications that stain the skin or irritate tissues. |
How is a Z tract injection performed? | The skin is pulled to one side prior to injection. Then the needle is inserted and the injection is performed. Once the needle is removed the skin is released so that the injection points in the skin and muscle are no longer aligned |
In a z tract injection why do you not want the skin and injection site to line up after the injection is made? | This keeps the drug from entering the subcutaneous tissue and staining or irritating the skin. |
How deep is z tract injection usually? | 2-3" deep |
Why choose the subcuteous route of administration? | Versatile and can be used for both short and long term therapies. |
Subcutaneous injection sites | Lower abdomen, front of thigh, upper back, back of upper arm, |
The injection of a drug or implantation of a device beneath the surface of the skin is made | in the loose tissues of the upper arm, the front of the thigh, and the lower portion of the abdomen. As well as the upper back. |
The maximum amount of subcutaneous injection is | 2ml |
needles are generally | 3/8 - 1" in length and 24-27 gauge |
What influences the absorption of drugs in the subcutaneous tissue? | muscle exercise, salt form used, size of particles |
Fewer blood vessels in SC or in IM? | SC |
Subcutaneous administration is | generally more rapid and predictable than with oral administration |
Using heat or massaging the injection site do what? | they have ben found to increase the absorption rate |
which is the most common drug administered SC? | insulin |
What kind of precautions should be observed when giving someone a SC inj? | drugs which are irritating or very viscous may produce serious adverse effects and be painful to the patient. |
Implant | One of the most popular ways to achieve very long term drug release is to place the drug in a delivery system or device that is implanted into the body tissue |
where is the implant preferred? | into the SC layer of skin |
Implantation generally requires | a surgical procedure or a specialized injection syringe |
implants are required to be | biocompatible |
an advantage to using the subcutaneous implantation? | it can be easily removed if nessescary |
what type of SC implants can be used? | Birth control, prostate cancer treatment, degradable microspheres, vapor pressure devices for morphine delivery, osmotic pressure devices for insulin and magnetically activated pellets |
biocompatibility | not irritating; does not promote infection or abscess |
wheal | a raised blister like area on the skin caused by an ID injection |
Intradermal injections involve | small volumes that are injected into the top layer of skin |
An ID injection does what once the formula is injected? | forms a wheal or blister like area from which the drug will slowly be absorbed into the dermis. |
the dermis is | the layer of skin below the epidermis, containing more blood vessels than the epidermis but fewer than most other injection sites |
what is the rate of absorption in an ID injection | absorption is gradual |
Where would you give an ID injection? | The anterior surface of the forearm. |
When giving an ID injection how long are the needles? | generally 3/8" long |
what gauge are the needles for an ID injection? | 25 to 26 gauge |
How is the ID injection made? | the needle is inserted horizontally into the skin with the bevel facing up. The injection is mde when the bevel disappears under the skin |
max. volume administered by ID injection | 0.1 ml |
Ophthalmic drugs used for things like | various eye conditions and for anesthesia |
ophthalmic formulations are | aqueous solutions, aqueous suspensions, ointments, and implants |
every ophthalmic product must be | sterile in its final container |
because of the sensitivity of eyes, what must be closely monitored? | PH and viscosity |
normal volume of tears in the eye | 7 microliters |
if blinking occurs | the eye an hold 10 mcl |
normal commercial eye droppers hold | 50 mcl |
what would the dose lost from overflow percentage? | 80% |
the ideal volume of a drug solution to administer would be | 5-10 mcl |
Some disadvantages to ophthalmic administration | lacrimal drainage and very rapid absorption by the eyelid lining |
where do the tears that wash the eyeball flow from? | the lacrimal gland across the eye and rain into the lacrimal canalicula. |
tear production for the average man is | 2mcl per minute |
the entire ear volume in the eye turns over every | 2-3 minutes |
systemic absorption is caused by | rapid washing of the eye by tears |
the drug is rapidly carried away from the eye | after being absorbed by the eyelid and enters the circulatory system |
ophthalmic ointment tubes are typically small, holding and fitted with | approx. 3.5g with a narrow gauge tip which permit the extrusion of a ribbon or ointment |
Lacrimal gland | the gland that produces tears for the eye |
lacrimal canicula | the tear ducts |
conjunctiva | the eyelid lining |
transcorneal transport | drug transport into the eye |
the capacity of the Intranasal cavity is | approx. 20 ml |
benefits from Intranasal administration | large surface area for absorption and a very rich blood supply |
what are the most common intranasal drugs used for? | used for decongestant activity on nasal mucosa |
other popular intranasal drugs | antihistamines and corticosteroids |
the intranasal absorption of some drugs produces what | blood concentrations similar to when the drug is IV administered |
Intranasal administration serves as a possible route of administration for drugs that are | seriously degraded or poorly absorbed after oral administration. |
IN formulations include | solutions, suspensions, ointments and gels |
IN solutions or suspnsions are generally administered as | drops or a fine mist from nasal spray or aerosol container |
why are nasal sprays preferred to drops | drops are more likely to drain into the back of the mouth and throat and be swallowed. |
what have plastic bottles been replaced by | glass containers with a metered dose inhaler actutor |
MDI actuator | metered dose inhaler actuator |
3 types of IN Devices for administration | Nasal spray with MDI actuator, nasal aerosol, nasal inhaler |
Nasal inhaler | a device which contains a drug that is vaporized by inhalation |
a nasal inhaler includes | a cylindrical tube with a cap, that contains fiberous material impregnated with a volatile drug |
how does a nasal inhaler work? | the cap is removed, the inhaler is tip is placed inside the nostril, as the paient inhales air is pulled through the tube and the vaporized drug is pulled into the nasal cavity |
nasal mucosa | the cellular lining of the nose |
nasal cavity | the cavity behind the nose and above the roof of the mouth that filters air and moves mucous and inhaled contaminants outward and away from the lungs |
3 ways an IN dosage can be lost | the nasal linings enzymes can degrade and metabolize some drugs, normal mucous flow will carry the drug with it, some amounts of IN administered drugs are swallowed |
if IN dosages are used for long periods of time, | may lead to chronic swelling of the nasal mucosa |
how long should you use IN doses? | 3-5 days |
edema | chronic swelling |
what are inhalation dosage forms for | intended on delivering drugs to the pulmonary system |
why use an inhalation dosage? | the lungs have a large surface area for absorption and a rich blood supply. also, avoids problems of degradation and poor absorption |
Inhalation is not considered n alternative route of administration to IV because | inconsistency in the absorption of drugs from the lungs |
The most important drugs administered by the inhalation route | Gaseous or volatile anesthetics |
other drugs administered by the inhalation route affect | lung function, act as bronchodilators and antiallergic |
Most inhalation dosages are | MDI aerosols that depend on the power of compressed or liquefied gas to expel the drug from the container |
aerosols are easy to use and have no danger of contamination, but | are not very effective in delivering a drug to the respritory tract |
aerosols are not effective in delivering the drug to the respiratory tract not due to the poor design of aerosol design, but | to the physical bariers of the airway and lungs that any inhalation dosage form must overcome to be effective |
What is a critical factor with an inhalation dose? | particle size. |
Large particles (20 microns)hit | the back of the throat and mouth and are eventually swallowed rather than inhaled |
Particles from 1-10 microns | reach the bronchioles |
smaller particls (.6 microns) | penetrate the alveolar sacs of the lung where absorption is rapid but retention is limited sine a fraction of the dose is inhaled |
breathing patterns and the depth of breathing also play important roles in the delivery of what | the delivery of drugs into the lung by inhalation aerosols |
Alveolar sacs | (alveoli) the small sac of specialized tissue that transfer oxygen out of inspired air into the blood and carbon dioxide out of the blood and into the air for exhlation |
inspiration | breathing |
places an inhalation dose is absorbed in the lungs | alveoli and bronchioles |
inhalation administering devices | an atomizer, diskus, nebulizer, MDI aerosol, MDI aerosol with spacer |
MDI aerosols for inhalation admin. | Used to administer drugs by inhalation and have special metered doses when the aerosol is activated. The amount of medicine released is regulated by a valve that has a fixed capacity or fixed dimensions |
Adapters and spacers | Developed to assist patients who cannot coordinate the breathing in and atuation of the aerosol |
Dry powder inhalers | Administered in powder form using a special inhalation device. The device automatically releases the drug when the user inhales. The powdered drug is supplied in hard gelatin caps, cartridges, or disks |
Atomizers and nebulizers | Devices which break up liquid into a spray. As the liquid vaporizes the air stream created carries the spray out of the vessel and into the mouth |
what is the largest, heaviest organ | skin, accounts for 17% of a persons weight. |
what does skin do | preforms a barrier that protects the underlying organ systems from trauma, temp, humidity, harmful penetrations, moisture, radiation and micro organisms |
What do you call dosage forms that are applied to the skin? | Dermal dosage formulations |
What are most dermal dosage forms used for? | local effects on or within the skin |
what are dermal formulations used for | protectants, lubricants, emollients, or drying agents, or as a delivery vehicle for a drug |
what do some dermal formulations promote? | Percutaneous Absorption |
Percutaneous Absorption | Absorption through the skin |
Advantages to dermal administration | ease of administration, usage by patients is generally good, can provide continuous drug delivery, dermal administration an be easily removed |
major disadvantages of dermal administration | amount of drug that can be absorbed is limited to about 2/mg per hr. |
skin is generally how thick | 3-5 mm |
where is skin thicker | palms and soles of feet |
where is skin thinner | eyelids and genitals |
other structures with the skin | hair follicles, sebaceous glands, sweat glands and nails |
what is the outer layer of epidermis called | Stratum corneum |
How is the stratum corneum continually replaced | by skin cells underneath |
what is the turnover time of skin cell from cell development to shedding of the dead cells? | 21 days |
Sloughing | Shedding of dead cells |
The stratum corneum is the primary barrier to | drug penetration |
How thick is the stratum corneum? | 10 micrometers thick but can swell up to approx. 3x that by absorbing as much as 5x its weight in the water. |
What happens when the stratum corneum hydrates, or absorbs water? | it becomes easier for drugs to penetrate |
percutaneous absorption | the absorption of drugs through the skin, often a systemic effect |
Dermal formulations are | Solutions, tinctures, collodions, liniments, ointments, creams, gels and lotions, pastes, powders and plasters, transdermal patches, tape and gauzes |
Dermal solutions and tinctures are generally used as | antiinfective agents, generally dispensed in small volumes |
collodions are liquid preperations of | pyroxylin dissolved in a solvent mixture of alcohol and ether |
Liniments are | alcoholic or oleaginous solutions generally applied by rubbing |
What are the most popular dermal formulations? | Ointments, creams, gels and lotions |
Advantages to vaginal administration | Avoids degradation of dosage,doses can be retrieved, has the potential of providing long term drug absorption |
disadvantages to vaginal administration | leads to vaiable absorption rates, administration of formula during menstruation could predispose patient to TSS. Also a tendency or some dosages to be expelled after insertion into the vagina |
Vaginal formulations include | solutions, powders for solutions, ointments, creams, aerosol foams, suppositories, tablets and IUDs |
IUD | intrauterine device |
contraceptive | device or formulation designed to prevent pregnancy |
TSS | Toxic shock syndrome, rare and potentially fatal that results from a severe bacterial infection of the blood, caused when bacteria natural to the vagina enters the blood stream |
Systemic | something that is wide spread throughout, system wide, affecting the whole boy |