Forms, Routes and Special Administration

Introduction

A medicine name tells you which drug is involved. It does not tell you what the product is, where it goes in the body, how much drug each unit contains, or how fast the drug is released. Those four facts decide how the product must be handled. A pharmacy technician needs to keep them separate, because a product can match on one and differ on another.

This lesson teaches you to read those four facts, to treat crushing or opening a product as a label question, and to notice when an order is missing information you need before preparing something.

What you will be able to do

• Name a product's dosage form, route, strength and release design separately, and explain why matching one does not mean matching the others.
• Explain why you check the exact product label before anyone crushes, splits, chews or opens a tablet or capsule.
• Identify missing instructions before reconstituting or preparing a product, and pass the question to the pharmacist instead of guessing.

Before you start: You need everyday reading and arithmetic. It also helps to know how to separate a drug's ingredient from its product details, which is covered in Read a medicine identity before learning a name. The arithmetic here stays simple. Concentrations, ratios and dilutions covers it in more depth.

The PTCE content outline lists strengths, dosage forms, routes, special handling and administration instructions, and duration of therapy as one area of medication knowledge. It also lists wrong route among the types of prescription errors.

Four questions to ask about every product

Picture one active ingredient that is sold in several products. To know which product you are holding, answer four questions. Each answers something different.

• Dosage form: What physical thing is it?
• Route: Where does it enter or touch the body?
• Strength: How much drug is in each unit, or in each measured amount of liquid?
• Release design: When and how fast does the drug come out after it is taken?

We will take them one at a time.

Dosage form: what the product physically is

Dosage form means the physical form of the product: a tablet, a capsule, a liquid, a cream, an inhaler, a powder for injection. The FDA keeps an official list of dosage form terms, such as "TABLET," "CAPSULE, EXTENDED RELEASE" and "INJECTION, POWDER, FOR SOLUTION."

Two liquid forms are easy to confuse:

• A solution is a liquid in which the drug is fully dissolved, like sugar stirred into water until it disappears.
• A suspension is a liquid in which solid drug particles are spread through the liquid but not dissolved. Given time, the particles can settle.

That difference explains a handling rule. Amoxicillin oral suspension labeling says to shake it well before each use. If the particles have settled, a dose drawn from the top could hold less drug than intended. Shaking spreads the particles evenly again.

Some forms are made in the pharmacy. A powder for oral suspension is a dry powder that becomes a suspension only after a measured amount of water is added. Adding liquid to a powder to make the usable product is called reconstitution.

Here is one ingredient in several forms. MedlinePlus lists amoxicillin as a capsule, a tablet, a chewable tablet and a suspension. Chewable tablets must be chewed completely before swallowing. That instruction belongs to the chewable form, not to amoxicillin in general.

Forms can also differ in what else they contain. On one amoxicillin label, the chewable tablets contain aspartame, a source of phenylalanine, but the oral suspension does not. The active ingredient is the same, and the formulation is not.

Question 1

A bottle reads "for oral suspension" and contains a dry powder. A coworker says, "It's a suspension, so just shake it and hand it out." What is wrong with that reasoning?

Route: where the drug enters or touches the body

Route of administration means the path the drug takes into or onto the body. The FDA's route standard defines common routes this way:

• Oral: to or by way of the mouth.
• Respiratory (inhalation): into the respiratory tract by breathing in through the mouth or nose.
• Intravenous (IV): into a vein.
• Intramuscular (IM): into a muscle.
• Subcutaneous: beneath the skin.
• Topical: to a particular spot on the outer surface of the body.
• Ophthalmic: to the external eye.
• Otic (auricular): to or by way of the ear.

Albuterol shows why you must read the route carefully. MedlinePlus calls the product "albuterol oral inhalation." The word "oral" there describes the mouth as the entry point for breathing in. The drug is meant to reach the airways. It is not meant to be swallowed. Albuterol comes in three inhaled forms:

• An inhalation aerosol, used with an inhaler.
• A powder for oral inhalation, used with a different inhaler.
• A solution, turned into an inhalable mist by a jet nebulizer.

All three share the inhalation route, but the devices are not interchangeable. MedlinePlus says the aerosol's inhaler is designed for use only with an albuterol canister. It also says the powder inhaler it describes should not be used with a spacer. Each device follows its own product's instructions. Matching devices to products is covered further in Product-specific respiratory and injection equipment.

Route can also depend on how a product will be used. Omeprazole granules for oral suspension can be taken by mouth or given through a feeding tube. MedlinePlus tells feeding-tube users to ask their doctor how to take the medication. A different route calls for its own directions.

Question 2

An injectable powder's carton reads "For Intravenous or Intramuscular use." An order names the drug and the dose but no route. Can the technician choose one, since both are on the carton?

Strength: how much drug per unit or per volume

Strength is the amount of drug in the product. The FDA describes it two ways:

• Amount per unit: for example, mg per tablet or mg per vial.
• Concentration: the amount per measured volume, for example, mg per 5 mL of liquid.

One amoxicillin label lists tablets at 500 mg and 875 mg, chewable tablets at 125 mg, 200 mg, 250 mg and 400 mg, and suspension at 200 mg/5 mL and 400 mg/5 mL. Same ingredient, many strengths.

For liquids, strength decides the volume. Take a fictional case. The dose is 300 mg, and two fictional suspensions are on the shelf.

• Stock A is 150 mg/5 mL. 300 mg ÷ 150 mg = 2, so you need 2 × 5 mL = 10 mL.
• Stock B is 300 mg/5 mL. 300 mg ÷ 300 mg = 1, so you need 1 × 5 mL = 5 mL.

To check: 10 mL of Stock A contains (10 ÷ 5) × 150 mg = 300 mg. The dose stays the same, while the volume changes with concentration. If you calculate with one concentration and pick up the other bottle, the patient gets double or half the dose, even though the arithmetic was done "correctly."

Strength is not the same as release design. A long-acting tablet is not "stronger" because it lasts longer. A 50 mg extended-release tablet and a 50 mg immediate-release tablet hold the same amount of drug. They differ in how the drug comes out.

Question 3

A fictional dose is 200 mg. The bottle you picked up is 400 mg/5 mL. A coworker calculated 5 mL using a 200 mg/5 mL bottle. Which volume matches your bottle, and what went wrong?

Release design: when and how fast the drug comes out

Release design describes the timing of drug release after the product is taken.

• Immediate release (also called standard or regular): the drug is released promptly after it is taken. Products that carry no release label usually work this way.
• Extended release (ER): the drug is released slowly over a longer time at a controlled rate. In plain terms, the dose is spread out.
• Delayed release (DR): the drug is released later than right away, not slowly. Enteric-coated products are delayed release. In plain terms, the dose waits, then is released.

Omeprazole shows why delayed release exists. MedlinePlus explains that its delayed-release forms release the drug in the intestine to prevent the drug from being broken down by stomach acid. The design protects the drug on its way past the stomach.

Metoprolol shows how release design can change directions. MedlinePlus lists a regular tablet, taken once or twice a day with or right after meals, and extended-release tablets and capsules, taken once a day. The ingredient is the same, but the schedule differs because the release design differs.

Extended and delayed are easy to mix up. Extended answers "How long does release last?" Delayed answers "When does release begin?" Both modify release. They are different designs, and they are not more powerful versions of the regular product.

Question 4

A product label reads "TABLET, DELAYED RELEASE." A coworker says, "Delayed release means it lasts all day, so it's like the extended-release version." Correct the statement.

Same ingredient does not mean same product

Now put the four questions together. The FDA's Orange Book uses precise terms for comparing products:

• Pharmaceutical equivalents have the same active ingredient in the same amount, the same dosage form and the same route.
• Pharmaceutical alternatives have the same therapeutic ingredient but may differ in amount, dosage form, or salt form. The Orange Book specifically lists extended-release products compared with immediate-release products of the same ingredient as pharmaceutical alternatives, not equivalents.
• Therapeutic equivalents are pharmaceutical equivalents that have also been shown to perform the same in the body (bioequivalent). They can be expected to have the same clinical effect and safety when used as their labeling directs.

Take a worked comparison. An order is for metoprolol extended-release tablets. The shelf holds metoprolol regular tablets of the same strength in milligrams. The ingredient and strength match, but the release design does not, so the products are pharmaceutical alternatives. The regular tablet also has a different dosing schedule. It is a different product, and the technician cannot treat it as a substitute.

Now change one fact. The order is for regular metoprolol tablets, and both shelf products are regular tablets of the same strength made by different manufacturers. The form, route, strength and release design now all match. Whether they may be swapped depends on how the FDA rates them and on your pharmacy's procedures, not on how similar they look.

A shared use does not make two drugs interchangeable either. The Orange Book says therapeutic equivalence applies only to products with the same active ingredient. It does not cover different drugs used for the same condition. Replacing a drug with a different drug for the same purpose is called therapeutic substitution. The PTCE content outline lists it among issues that require pharmacist intervention.

FDA equivalence terms describe products. They are not your pharmacy's whole substitution rulebook. Who may substitute, and how, also depends on state rules and pharmacy policy, which this lesson does not cover.

Question 5

A prescription is for an immediate-release tablet. The pharmacy is out of it but has an extended-release tablet of the same ingredient and the same mg strength. Another drug used for the same condition is also in stock. What is your role?

Crushing, splitting or opening: check the exact label

Patients and caregivers often ask whether a tablet can be split or crushed, or whether a capsule can be opened, usually because swallowing is hard. You might expect one rule for each type: never crush ER, always open capsules. The labels show there is no such shortcut.

Worked example 1: Metoprolol, two extended-release products. MedlinePlus says:

• The extended-release tablet may be split. Whole or half tablets are swallowed without chewing or crushing.
• The extended-release capsule must not be split, chewed or crushed. A patient who cannot swallow it may open it and sprinkle the contents onto a spoonful of soft food such as applesauce, pudding or yogurt. The mixture is swallowed right away and not used more than 60 minutes after it is made.

Both products are extended release, yet splitting is allowed for one and not the other. Opening is allowed for one, and only in a specific way, with soft food and a time limit.

Worked example 2: Omeprazole, two delayed-release products. MedlinePlus says:

• The delayed-release tablet must be swallowed whole. It must not be split, chewed or crushed, or crushed and mixed into food.
• The delayed-release capsule is normally swallowed whole. A patient who has trouble swallowing can open it, empty all the granules onto a tablespoon of soft, cool applesauce, and swallow the mixture right away. The granules must not be chewed or crushed, and the mixture must not be saved.

What the contrast shows. Metoprolol's ER tablet may be split, but omeprazole's DR tablet may not. Both are modified-release tablets with opposite splitting rules. The opening methods that are allowed keep the release-controlling contents whole: the granules are swallowed uncrushed, not ground up. Even so, an allowed opening method for one capsule tells you nothing about crushing a different product.

Why the exact label decides. The release design is built into each specific product. Omeprazole's delayed release exists to protect the drug from stomach acid. Breaking the product in a way its label forbids works against the design the label depends on. The reasoning helps you take the warning seriously, but the label is what settles the question. Two products in the same category can have different instructions, and a product's directions apply only to that product.

Your role. Recognizing the issue is your job. Deciding what happens clinically is not. If a patient cannot swallow a product as labeled, the next step is the pharmacist. A technician does not suggest crushing, does not propose a different product, and does not borrow another product's opening method.

Question 6

A caregiver says their parent cannot swallow omeprazole delayed-release capsules. They ask whether to crush the granules into applesauce so they mix in better. What is the issue, and what do you do?

Before you prepare: look for missing instructions

Some products are finished in the pharmacy: an oral powder reconstituted with water, or an injectable powder reconstituted and sometimes further diluted. Before you begin, confirm that you have every instruction the preparation requires. Correct arithmetic does not replace a missing instruction.

Worked example: an oral suspension made from powder

One amoxicillin for oral suspension label gives directions for mixing at the time of dispensing:

• Tap the bottle until the powder flows freely.
• Measure the total water from the label's table.
• Add about one third of the water, cap the bottle, and shake vigorously to wet the powder.
• Add the remaining water and shake vigorously again.

After mixing, the label says to shake well before each use, keep the bottle tightly closed, and discard unused suspension after 14 days. Refrigeration is preferred but not required.

The label's water table gives a different amount for each combination of strength (200 mg/5 mL or 400 mg/5 mL) and bottle size. Before you can mix, you therefore need to know:

• Which strength: the water amount depends on it.
• Which bottle size: the water amount depends on it too.
• Which product's label: the Orange Book notes that equivalent powders may differ in expiration time and storage after reconstitution, and that equivalence holds only when each is reconstituted, stored and used as its own labeling directs. Another manufacturer's 14-day limit or water amount may not match yours.

Change one fact. Suppose the prescription specifies a total dose in milligrams but not which concentration to use. You could calculate a volume for 200 mg/5 mL and a different volume for 400 mg/5 mL. Both calculations would be correct, but you would still not know which product is intended. That is a missing instruction, and it goes to the pharmacist.

Bottle length is not treatment length. MedlinePlus says amoxicillin is taken every 8 or 12 hours. It also says the length of treatment depends on the type of infection. How often a dose is taken is a different fact from how many days treatment lasts. Dividing bottle volume by daily volume tells you how long the bottle lasts, not how long the prescriber wants treatment to continue. If the prescription leaves the duration unclear, ask. Days-supply arithmetic is taught in Calculate days supply. Storage after mixing is taught in Stability, storage and temperature excursions.

Worked example: an injectable powder, reconstituted versus further diluted

Injectable powder labels often separate two steps:

• Reconstitution: adding a specified liquid to dissolve the powder.
• Further dilution: adding more of a specified liquid to the reconstituted solution, which some uses require.

One cefazolin label, for a powder labeled for IV or IM use, does exactly this. It names the liquid used for reconstitution. It then calls for further dilution for some IV methods and names which IV solutions may be used. The steps depend on the route, which is why a missing route blocks preparation. The label also says to inspect the product for particles and discard it if any are present, and it gives storage time limits after reconstitution or dilution. Those directions belong to that product. They are not a general recipe.

Why further dilution lowers concentration. Concentration is the amount of drug divided by the volume. Adding drug-free liquid increases the volume without adding drug.

Take a fictional vial with every assumption supplied. It contains 1,000 mg of drug, and its fictional label says reconstitution yields 4 mL of solution.

• After reconstitution: 1,000 mg ÷ 4 mL = 250 mg/mL.
• Suppose all of it is further diluted to a fictional total of 50 mL: 1,000 mg ÷ 50 mL = 20 mg/mL.
• To check: 20 mg/mL × 50 mL = 1,000 mg. The amount of drug never changed. Only the volume did.

If you do not know whether a further dilution applies, which liquid to use, or what final volume is intended, you cannot know the final concentration. Each of those is a missing instruction.

Question 7

A technician is asked to reconstitute an oral antibiotic powder. They have the drug name, the dose in mg, and "take twice daily." The shelf holds two strengths of the powder, each from a different manufacturer. What instructions or information is still missing?

A process you can use every time

1. Name the four attributes of the ordered product and of the product in your hand: dosage form, route, strength, release design. Any mismatch, even with the same ingredient, means stop and ask the pharmacist.
2. Read the exact product label for handling words such as "do not crush," "may be split," "may be opened," "shake well," and "for oral suspension." Apply only the instructions for that product.
3. Check the order for missing pieces: route, strength or concentration, dose, frequency, duration, and any preparation details the label needs, such as which liquid, how much, and whether further dilution applies.
4. Calculate only from the product you hold, then check by reversing the calculation.
5. Route clinical questions to the pharmacist: swallowing trouble, swaps, therapeutic substitution, unclear routes. Spotting these is your job. Deciding them is the pharmacist's job.

For more on step 5, see Recognize when the pharmacist must intervene.

Independent practice

Question 8

A fictional label reads: "Drug X 25 mg extended-release capsules. Take by mouth once daily." Identify the dosage form, route, strength and release design.

Question 9

A patient's metoprolol extended-release tablets are prescribed. The patient's family says that a relative opened metoprolol extended-release capsules onto applesauce. They ask whether the tablets can be crushed into applesauce the same way. What do you recognize, and what do you do?

Question 10

A fictional oral suspension is 125 mg/5 mL. The dose is 250 mg twice daily, and the bottle holds 100 mL. Calculate the dose volume and how many days the bottle lasts. Then say what this does not tell you.

Question 11

A fictional injectable powder vial holds 500 mg. Its fictional label says reconstitution yields 2 mL. An order says to "give IV after further dilution" but gives no final volume or diluent. What is the concentration after reconstitution, and can you finish the preparation?

Question 12

Two products have the same active ingredient, the same strength and the same route. One is "tablet," and the other is "tablet, delayed release." A coworker says, "They're the same drug for the same problem, so they're interchangeable." Explain the error.

What to remember

• Every product has four separate attributes: dosage form (what it is), route (where it goes), strength (how much drug per unit or per volume), and release design (when and how fast the drug comes out). Matching on one does not mean matching on the others.
• The same ingredient can come in different products. Immediate-release and extended-release versions of one ingredient are pharmaceutical alternatives, not equivalents. A shared use never makes two different drugs interchangeable.
• Splitting, crushing, chewing and opening rules are product-specific. Two extended-release products, or two delayed-release products, can have opposite rules. Read the exact label, and route swallowing problems to the pharmacist.
• Before preparing a product, confirm route, strength, dose, frequency, duration, and the label's preparation details. Reconstitution and further dilution are separate steps, and adding liquid lowers concentration without changing the amount of drug.
• Correct arithmetic shows how much. It does not authorize dispensing when an instruction is missing.