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Design a Delayed-Release Tablet

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Grade Range
Group Size
4 students
Active Time
2 hours 45 minutes
Total Time
2 hours 45 minutes
Area of Science
Materials Science
Key Concepts
Medicine, materials science
Svenja Lohner, PhD, Science Buddies
Bath tablets, built example tablets and a stopwatch next to a cup of water that has a dissolving example tablet in it.


In this lesson, students are challenged to design and build a controlled-release tablet, which will be made from different colored bath tablets and a variety of water-soluble plastics. First, they will have to test the properties of each of the different plastic materials. Then their task will be to create a tablet that releases three different colors, each at a pre-determined time after the tablet has been submerged in water. As students design and build their controlled-release tablets, they will realize how the properties of each material affect their results. At the same time, students will get insight and exposure to drug formulation and development procedures.

Learning Objectives

NGSS Alignment

This lesson helps students prepare for these Next Generation Science Standards Performance Expectations:
This lesson focuses on these aspects of NGSS Three Dimensional Learning:

Science & Engineering Practices Disciplinary Core Ideas Crosscutting Concepts
Science & Engineering Practices Planning and Carrying Out Investigations. Conduct an investigation and/or evaluate and/or revise the experimental design to produce data to serve as the basis for evidence that meet the goals of the investigation.

Collect data about the performance of a proposed object, tool, process, or system under a range of conditions.

Constructing Explanations and Designing Solutions. Apply scientific ideas or principles to design, construct, and/or test a design of an object, tool, process or system.

Undertake a design project, engaging in the design cycle, to construct and/or implement a solution that meets specific design criteria and constraints.

Optimize performance of a design by prioritizing criteria, making tradeoffs, testing, revising, and retesting.
Disciplinary Core Ideas PS1.A: Structure and Properties of Matter. Each pure substance has characteristic physical and chemical properties (for any bulk quantity under given conditions) that can be used to identify it.

ETS1.C: Optimizing the Design Solution. Although one design may not perform the best across all tests, identifying the characteristics of the design that performed the best in each test can provide useful information for the redesign process—that is, some of the characteristics may be incorporated into the new design.

The iterative process of testing the most promising solutions and modifying what is proposed on the basis of the test results leads to greater refinement and ultimately to an optimal solution.
Crosscutting Concepts Structure and Function. Structures can be designed to serve particular functions by taking into account properties of different materials, and how materials can be shaped and used.


Materials needed for the delayed release tablet lesson.

For each student group:

For groups to share:

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Background Information for Teachers

This section contains a quick review for teachers of the science and concepts covered in this lesson.

Medication comes in many forms such as liquids, capsules, tablets, creams, drops, sprays, or injections (Figure 1). The main purpose of medication is to treat, cure, or prevent a disease in an individual. This is achieved by a chemical inside the drug, called the active ingredient, which interacts with the drug's target inside the body and thus has a certain effect on a person. For a drug to be effective, it has to be inside the body at the site of action for the correct time and duration. For example, a drug that is injected goes directly into the bloodstream whereas oral tablets pass through the digestive system and the active ingredient is then absorbed into the bloodstream. The active ingredient not only has to be at the right place at the right time, but it also has to have the right dosage. If the dosage of the drug is too low, it won't have the desired effect. If the dosage is too high, it could have harmful consequences and even be fatal!

Different forms of mediations such as vials with liquid, pills, and tablets.
Figure 1. Medicine can take the form of capsules, tablets, or injections.

This is where drug delivery systems come in. A drug delivery system is a specific form of medication or a medical device that is able to control the rate, time, and place at which a certain drug is introduced into the body. A drug delivery system allows to specifically target where and when a drug is released inside the body. Many different drug delivery techniques have been developed. Among these are controlled-release drugs. These types of drugs release their active ingredient at a prespecified time.

One specific type of controlled-release drug is a delayed-release drug. Delayed-release drugs are medications, such as capsules or tablets, which do not immediately disintegrate when taken. Because of this, the active ingredient is released slowly in smaller portions, rather than immediately after being administered. This includes, for example, enteric-coated drugs that are designed to delay the release of the medication until the tablet has passed through the stomach. This prevents the active ingredient from being destroyed or inactivated by stomach fluids. The delayed release of the active ingredient is often achieved by coating or encapsulating the active ingredient in a polymer film that gradually dissolves over time, as shown in Figure 2.

Schematic of the dissolving mechanism of delayed release tablet. The encapsulating layer slowly dissolves until it releases the active ingredient.
Figure 2. Delayed-release drugs are often encapsulated in polymers that dissolve over time.

Choosing the right encapsulation polymers with the right physical and chemical properties is crucial for designing delayed-release drugs. Polymers, which are large chains of many repeating subunits, can have very different properties depending on their molecular composition. This is why their properties have to be carefully tested. This includes testing not only the way in which the polymers dissolve in different solutions but also their toxicity in the human body as well as their interaction with the active drug ingredient.

In this lesson, students are challenged to design and build a delayed-release tablet, which will be made from different colored bath tablets and a variety of water-soluble plastics. Their task will be to create a tablet that releases each color from the bath tablets at a pre-determined time after it has been submerged in water. Before students start making their tablets, they will have to test the properties of each of the different materials they have been given, such as their dissolution behavior in water as well as other characteristics. As students design and build their delayed-release tablets, they will realize how the structure and properties of each of their materials influence their results. At the same time, students will get insight and exposure to drug formulation and development procedures.

Prep Work (30 minutes)

Engage (20 minutes)




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