Drug formulation and pH
This page has four parts, in the order you use them. Part 1 is what you need to know. Part 2 says what to do, in plain English. Part 3 shows the work done once on a case that is not yours. Part 4 is your own work and where to turn it in.
Open your materials, follow the steps, then turn in your work.
Separate a drug's active from its inactive ingredients and explain why a pill must survive the stomach and open in the small intestine.
Optional: listen or watch a unit review▸
Part 1 of 4 · Background and definitions▸
💡 Big idea: A pill has to survive one organ to reach another, so the coating is solving a transport problem, not a chemistry-class problem.
- • The active ingredient is the part of a pill that acts on the body; the inactive ingredients (binder, filler, coating, coloring) hold it together and carry it to where it works.
- • Most drugs taken by mouth are absorbed in the small intestine, not the stomach, because its folded lining has a huge surface area.
- • Stomach fluid sits near pH 2; the small intestine runs from about pH 6 in the duodenum to about pH 7.4 in the ileum. A lower pH number means more acid.
- • An enteric coating holds in stomach acid and gives way in the less acidic small intestine. Alginate forms a gel when calcium ions cross-link its chains; shellac stays solid in acid and dissolves as the pH rises.
A design is defensible only when each feature traces to user evidence, so a CER forces justification because it makes you link every choice to a real need and a usability principle.
A pill has to survive one organ to reach another, so the coating is solving a transport problem, not a chemistry-class problem.
Driving question: An uncoated tablet is about to go into simulated stomach fluid. What do you predict happens to it, and which organ was that drug actually meant to reach?
What you already know: A design is defensible only when each feature traces to user evidence, so a CER forces justification because it makes you link every choice to a real need and a usability principle.
New idea: A pill has to survive one organ to reach another, so the coating is solving a transport problem, not a chemistry-class problem.
Visual or model: No figure is attached to this lesson. The readings, the worked example and E1 to E3 carry the evidence.
- Observe or measure the relevant feature in today's lesson.
- Organize the observation with a stable evidence ID.
- Apply this rule: Keep observations separate from explanations, then collect the evidence that can distinguish the options.
- Choose the option the evidence supports and state the limit of the conclusion.
Real biomedical example: An uncoated tablet is about to go into simulated stomach fluid. What do you predict happens to it, and which organ was that drug actually meant to reach?
What the evidence supports: E1 to E3 support the daily take-home when the response meets the stated success criteria.
What it cannot prove: The package does not support claims beyond this lesson's or any real patient diagnosis.
- • : The movement of digested nutrients, water, drugs, or other substances from the gut or another surface into the bloodstream so the body can use them.
- • hypothesis: A testable, falsifiable prediction about how variables relate, written so an experiment can support it or prove it wrong.
- • observation: Information gathered directly through the senses or instruments, recording what actually happens without yet interpreting it.
- • : The one factor a researcher deliberately changes in an experiment to test its effect on the measured outcome.
- • : The outcome a researcher measures in an experiment, which may change in response to the variable being tested.
- • : A factor kept the same across every group in an experiment so it cannot secretly affect the results.
Use it now: Choose one decision option. Cite E1 and E3, then explain how the rule connects the evidence to your choice. This is thinking practice for the one turn-in named under Turn in, not a second submission.
Go further, optional: The source links below are optional enrichment. Every fact required for today's local evidence decision appears in this lesson package.
Digestion uses coordinated mechanical and chemical processes to break down food, absorb nutrients, and move material, with each organ contributing a distinct part of the system.
Limit: A classroom model simplifies regulation, individual variation, microbial interactions, and disease.
Keep observations separate from explanations, then collect the evidence that can distinguish the options.
Limit: Biomedical investigations use controlled procedures and validated measurements, not intuition alone.
State why , not digestion, is the target and which organ does it.
Limit: E3 defines the classroom product or success criterion. It is not independent scientific evidence and cannot justify a clinical or causal claim.
Today's decision · Simulated classroom evidence scenario
Your role: biomedical team member
Decision: Your team must decide what the evidence from today's lesson supports before submitting the exit response named on today's page.
- • Run the uncoated tablet demonstration first, because your written prediction has not yet been checked against what the acid actually did.
- • Choose the coating by the organ that absorbs the drug, because stomach acid and the small intestine sit at different points on the pH scale.
- • Treat digestion as the target and pick the coating that breaks down fastest in stomach acid, since a faster release reaches the patient sooner.
Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Use it inside the one turn-in named under Turn in; it is not a separate submission.
Claim ceiling: Today's evidence supports a classroom claim about today's lesson. It cannot prove causation, diagnose a real patient, or justify action outside this room.
Students often think a pill's ingredient list and assume everything that is not the drug is filler, added to make the tablet bigger or cheaper. The trap: The inactive ingredients are the delivery system. The coating is what decides whether the active ingredient survives the stomach and arrives at the small intestine, where happens. An active ingredient destroyed on the way is not a weaker dose, it is no dose at all.
- CER:
- Claim, Evidence, Reasoning: make a claim, back it with evidence, explain your reasoning.
- SOP:
- Standard Operating Procedure, the exact steps to follow (especially in a lab).
- Tracker:
- Your PLTW progress log where you record completed evidence.
- myPLTW:
- The PLTW course site where you do the online activities. Find it in Clever with your Microsoft sign-in, right next to Schoology.
Tap the speaker to hear a term. Add two of these to your notebook glossary with a definition and an example in your own words.
Pick just 2 or 3 words from today and make them yours: write what each one means in your own words, name the context clue or evidence that helped, then give one example from what you actually did in Drug formulation and pH. Try your own words first; the glossary is there if you get stuck. This is voluntary and counts as extra credit, so keep it short.
Saved on this device. Show Mr. Mendoza or add these to your notebook glossary to claim the extra credit.
Part 2 of 4 · Directions in plain English▸
2.1 Open your materials
2.2 Start the work
Map the GI tract and name four accessory organs and what each contributes.
Show all 5 required steps
- Map the GI tract and name four accessory organs and what each contributes.
- Place stomach and small intestine on the pH scale and state which is acidic.
- Predict, in writing, what an uncoated tablet does in stomach acid before you watch the demonstration.
- Compare your prediction against the demonstration and record what differed.
- Name the two coating polymers and what cross-linking does to each.
Lost your place? Find the prediction you wrote in step 3. If it is on the page, go straight to step 4 and compare it against what the demonstration actually did. If it is not on the page, write what you expected now and mark it as written after the fact, because a prediction you backfilled is still usable as long as it is labelled.
- 0-8 minDo Now: which is more acidic, pH 2 or pH 7, and what in a pill is not the drug?
- 8-25 minMap the GI tract; name four accessory organs and what each contributes.
- 25-38 minPlace the stomach and small intestine on the pH scale; name the acidic one.
- 38-50 minWrite your prediction for an uncoated tablet in simulated stomach fluid, then watch the demonstration.
- 50-62 minCompare your prediction with the demonstration and record what differed.
- 62-72 minNotes: the two coating polymers and what cross-linking does to each.
- 72-80 minExit ticket: your prediction, what happened, and the organ the coating has to reach.
- • Today starts Unit 4 with a transport problem: a swallowed drug meets the acidic stomach first and the absorbing small intestine second.
- • Write your prediction for the uncoated tablet before the demonstration, because a prediction written after watching is not a prediction.
- • Read the pH scale in the right direction all day: a lower number means more acid.
- • The two polymers you name today, alginate and shellac, are the ones you coat pills with next class.
PLTW connection and today's work
Open myPLTW and locate Lesson 4.1 Designing the Future, Activity 4.1.5 Drug Design Lab. Read the digestive-tract and pH sections before the demonstration.
Today's stopping point: You finished Unit 3. Today starts Unit 4 with Lesson 4.1 Designing the Future: the tablet prediction, the demonstration and the pH scale. The myPLTW prompt, if it opens, belongs in the first 18 minutes.
PLTW activity titles identify the course connection. If your account will not open, use the posted materials for today and tell Mr. Mendoza. Do not mark an online activity complete unless you completed it.
Use the turn-in directions in Part 4 of this page. Do not create a second submission unless your teacher asks for one.
Show another explanation or a smaller first step
Need help? Choose a starting point
Part 3 of 4 · Worked example▸
This is a parallel case, not your own. Read it for the order of the work, then do your own in Part 4.
1. Decision or claim I am testing: ____
2. Evidence ID and exact observation: ____
3. Second evidence ID and exact observation: ____
4. Rule that connects the evidence to my claim: ____
5. Strongest alternative or tradeoff: ____
6. Limitation or missing evidence that controls my confidence: ____
7. Revision I would make if the missing evidence changed: ____
This model shows the level of evidence and organization needed to complete: A blank structure for organizing the assigned response. It contains no claim, ranking, calculation, data interpretation, or recommendation from today's task.
- Name the prompt or task.
- Answer it directly with the key evidence.
- Check that the response matches the requested format.
Keep the structure. Replace the question, facts, measurements, and evidence. Then recheck units, vocabulary, and whether the conclusion goes beyond the evidence.
Also due today: Submit as one PDF in Schoology.
A detective board holds observations, possible explanations, and one next question.
- Which notes are direct observations?
- Which notes are explanations?
- What new evidence would separate the explanations?
Keep observations separate from explanations, then collect the evidence that can distinguish the options.
Biomedical investigations use controlled procedures and validated measurements, not intuition alone.
- • Board notes map to the signs, results and measurements you recorded.
- • Possible explanations map to the competing biological causes.
- • The next question maps to the test or observation that would separate them.
Part 4 of 4 · Your work▸
Check your work before submitting
- State why absorption, not digestion, is the target and which organ does it.
- Read the pH scale in the correct direction: a lower number means more acid.
4.1 Turn in your work
DueCheck the Schoology assignment for this day- Hand in
- Exit ticket: your written prediction for an uncoated tablet in stomach acid, what the demonstration showed, and the organ the coating has to get the drug to, with the pH of the stomach and the small intestine.
How to submit and name your file
Submit as one PDF in Schoology.
In Schoology, open your course and the assignment for this lesson. Attach your file, select Submit, and check that it appears in the submission.
PDF upload helpYou get two school days for every day you were absent, so this deadline moves with you.
Today's lesson is in Schoology
Each school day has one lesson page in Schoology that holds everything for the day: the goal, the story so far, every table and data value, the numbered steps, and what to turn in. Open it first and work from it. The other rows for this day, if any, are the score line for a paper quiz or test and the John Carroll debate item; they do not add work. Check Schoology for each deadline.
- Today's Lesson · Fri 12/11 · Wk16 · Anaphylaxis: the medicine and the route, then the dose and osmosis(today's lesson page: the goal, the data, the steps, and what to turn in are all on it)
Link will not open? Open Schoology, choose your course and section, and find the title shown above.
- CompleteEvery required part of the artifact is present, nothing left blank.
- AccurateThe science and the data are correct and match the evidence.
- Scientific reasoningYou explain your claim with evidence and reasoning (CER), not just an answer.
- Professional communicationClear, organized, labeled, and written the way a clinician or scientist would.
- SubmittedGo to Schoology to turn this in. Submit one PDF. Schoology attaches your name to your upload; on the page itself, write your period and code. Name the file: FirstName LastName - Assignment Title - YYYY-MM-DD.pdf. If you cannot get in, see Mr. Mendoza. Do not skip the work.
How this lesson connects
Keep using what you learned last class: A design is defensible only when each feature traces to user evidence, so a CER forces justification because it makes you link every choice to a real need and a usability principle. Today: A pill has to survive one organ to reach another, so the coating is solving a transport problem, not a chemistry-class problem.
Practice: try a question, then check your answer▸
Claim ceiling for this check: Today's evidence supports a classroom claim about today's lesson. It cannot prove causation, diagnose a real patient, or justify action outside this room.
A tablet is built so its coating holds at pH 2 and gives way near pH 7. Commit to an answer before you read on: which organ does the coating hold through, which organ is the drug meant to reach, and what does the coating protect?
Write an answer and pick a confidence to unlock the key.
Missed class or ready for more?▸
Optional practice for this unit's lab skills. Nothing in it is due today.
Next class you coat practice pills and test them in simulated stomach and intestinal fluid. Before then: (1) name the two coating polymers and what cross-linking does to each; (2) define independent, dependent and for a coating test; (3) write why an observation every 30 seconds cannot be skipped; (4) remember the shellac solution is alcohol based and flammable, so no flame or heat source goes near it.
What today's skills lead to. These are real health-science careers this course builds toward. Tap one to see, on the US Department of Labor's O*NET site, what the job actually involves, what it pays, and how fast it is growing.
At home: map the digestive tract with four accessory organs, place the stomach and the small intestine on the pH scale, write what you predict an uncoated tablet does in stomach acid, and name the organ the drug has to reach.
NIDDK: Your digestive system and how it worksSubmit as one PDF in Schoology.
Class still runs. Complete today's work as this page describes (it is self-guided). Need the concept taught without a teacher? Use this authoritative explainer:
NIDDK: Your digestive system and how it worksThe optional extra-credit track is open. Complete reserved-unit work from home, including virtual labs, for extra credit. Each item shows its correct submission route.
Open the extra-credit trackSources: slides, readings, and resources▸
The deck carries the prior idea forward, lets you inspect an analogy, maps the rule to biology, and ends with the same evidence decision and exit ticket used on this page.
Play the cold open at the start of the unit to set the scene. Each recording is AI-generated and simulated (fictional callers, no real people or student data).
Hand-picked readings and interactives for this lesson, from authoritative open organizations and PLTW's own public course outline.
This week
My Progress dashboard