The basic steps: powder, binding, pressing, and coating
A tablet starts as a powder mixture of the active drug and several inactive ingredients called excipients. The manufacturer weighs and blends these powders together, then feeds them into a machine that compresses the mixture under high pressure into a solid form. After pressing, the tablet may be coated with a thin layer of material that controls how fast it dissolves in your stomach or makes it easier to swallow. The whole process, from raw powder to finished tablet, takes place in a climate-controlled facility where the air, water, and equipment are monitored constantly to keep the product safe.
The reason tablets are made this way instead of as liquids or capsules comes down to stability, cost, and how your body absorbs the drug. A solid tablet stays potent longer on a shelf, costs less to manufacture and ship than a liquid, and the compression itself can be tuned so the drug releases slowly or all at once depending on what the medicine needs to do.
Key Takeaways
- Tablets are made by mixing a drug powder with inactive ingredients, compressing the mixture under pressure, and sometimes coating the outside.
- The inactive ingredients—binders, fillers, disintegrants, and lubricants—make up most of the tablet's weight and control how it breaks down in your body.
- Tablet presses can produce thousands of tablets per hour, and each one is checked for weight, hardness, and appearance before it leaves the factory.
- The coating on a tablet can be designed to protect the drug from stomach acid, make the tablet easier to swallow, or slow down how fast the medicine is absorbed.
What goes into a tablet besides the active drug
The active ingredient—the chemical that actually treats your condition—is usually only 5 to 10 percent of a tablet's weight. The rest is made up of four main types of inactive ingredients, each with a specific job.
Binders hold the powder together so it doesn't crumble. Common binders are microcrystalline cellulose (a plant fiber), maltodextrin (a starch), and povidone (a synthetic polymer). Fillers add bulk so the tablet is large enough to handle and press. Lactose (milk sugar) and dicalcium phosphate are typical fillers. Disintegrants absorb water and swell when the tablet reaches your stomach, causing it to break apart so your body can absorb the drug. Croscarmellose sodium and sodium starch glycolate are common choices. Lubricants like magnesium stearate or silica are dusted onto the powder before pressing so the tablet doesn't stick to the machine dies.
The manufacturer chooses these ingredients based on the drug's chemical properties, how fast it needs to dissolve, and whether the tablet will be swallowed whole or chewed. A tablet meant to dissolve quickly in your mouth uses different excipients than one designed to release the drug slowly over eight hours.
How the powder becomes a solid tablet
Once the powder blend is ready, it goes into a tablet press—a machine with two metal dies (a top punch and a bottom punch) that squeeze the powder between them. Modern tablet presses are automated and can produce anywhere from a few hundred to over 10,000 tablets per hour depending on the machine's size and the tablet's shape. The operator sets the compression force, which is measured in kilonewtons (kN). Too little force and the tablet crumbles; too much and it becomes so hard that it won't dissolve in your stomach.
As each tablet is pressed, it's ejected onto a conveyor belt where it moves to the next stage. The tablet is still warm from the compression, and it hardens as it cools. Before the tablets are packaged, they pass through quality-control machines that check the weight (usually within 5 percent of the target), the hardness (how much force it takes to break), the thickness, and the appearance. Any tablet that falls outside these ranges is removed and destroyed.
Coating: why some tablets have a shell
Many tablets receive a coating after they're pressed. The coating is sprayed on in a large rotating drum, and the tablets tumble as the liquid coating dries on their surface. The coating can serve several purposes.
Enteric coating is designed to protect the drug from stomach acid. It dissolves only in the small intestine, where the environment is less acidic. This is used for drugs that would be destroyed by stomach acid or that irritate the stomach lining. Film coating is a thin, smooth layer that makes the tablet easier to swallow, improves its appearance, and can mask a bitter taste. Sustained-release coating contains tiny pores or is made from a material that dissolves slowly, so the drug is released gradually over several hours instead of all at once.
The coating material is usually a polymer like hydroxypropyl methylcellulose (HPMC) or polyethylene glycol (PEG), mixed with plasticizers and pigments. The coating adds 2 to 5 percent to the tablet's weight and takes several hours to dry completely.
Quality control and testing throughout manufacturing
Tablet manufacturing is one of the most regulated processes in the pharmaceutical industry. Before a single tablet is made, the manufacturer must validate every step—the blending, the pressing, the coating—to prove it produces the same result every time. This validation is documented and submitted to the FDA or the regulatory body in the country where the drug will be sold.
During production, samples are pulled from the line at regular intervals and tested for content uniformity (does each tablet contain the right amount of drug?), dissolution (does it break down at the right speed?), and hardness. The facility itself is inspected regularly, and records of every batch are kept for years in case a problem is discovered later and the batch needs to be traced.
Once manufacturing is complete, the tablets are packaged in bottles, blister packs, or other containers, labeled with the drug name, strength, expiration date, and storage instructions, and shipped to pharmacies and hospitals.
Why tablets are pressed instead of made other ways
Tablets are the most common form of oral medication because they're stable, portable, and cheap to make compared to capsules or liquids. A tablet can sit on a shelf for years without losing potency if stored in a cool, dry place. A liquid suspension—where the drug is mixed into a syrup—separates over time and requires shaking before each dose. A capsule costs more to manufacture because each one has to be filled individually, whereas a tablet press can stamp out thousands per hour.
Tablets also allow for precise dosing. Every tablet from the same batch contains nearly the same amount of drug, so you know exactly how much you're taking. With a liquid, it's straightforward to measure wrong, especially for children or elderly people with shaky hands.
The main drawback is that some people have trouble swallowing tablets, which is why chewable tablets, dissolving tablets, and capsules exist as alternatives. But for most medications, a pressed tablet is the standard.
Frequently Asked Questions
Why do some tablets have a line down the middle?
The line, called a score, is there so you can break the tablet in half if your dose is half a tablet. The score is pressed into the tablet during manufacturing. Not all tablets are scored—only those where splitting is safe and the two halves will contain equal amounts of drug. Never split a tablet unless your doctor or pharmacist says it's okay, because some tablets are designed to release the drug slowly and splitting them can change how fast the drug enters your body.
What's the difference between a tablet and a caplet?
A caplet is a tablet shaped like a capsule—oblong and smooth—but it's still made by pressing powder, not by filling a capsule shell. Caplets are easier to swallow than round or oval tablets because the shape slides down your throat more smoothly. The manufacturing process is the same; only the shape of the dies in the tablet press is different.
Can you tell what's in a tablet just by looking at it?
Not really. The color, size, and shape don't tell you what drug it is or how much is inside. That's why tablets are imprinted with a code—usually numbers or letters stamped into the surface during pressing. You can look up the code on a pill identifier website or ask your pharmacist to confirm what you're taking. The imprint is required by law so tablets can be identified if they're mixed up or if someone takes the wrong one by mistake.
Why do some tablets taste bitter even though they're coated?
A film coating makes the tablet easier to swallow and can mask some bitterness, but it doesn't seal the tablet completely. If you chew a coated tablet, you break through the coating and taste the drug inside. Some drugs are naturally very bitter, and no coating can hide that taste if the tablet is chewed. If you're supposed to swallow a tablet whole, do that instead of chewing it—the coating will protect your taste buds and the drug will work as intended.
How long does it take to make a tablet from start to finish?
The actual pressing takes seconds per tablet, but the whole process from raw materials to packaged product takes days or weeks. Blending the powder takes hours, pressing and coating take hours, quality testing takes hours, and then the tablets must dry completely before packaging. A single batch might contain millions of tablets, so even though each individual tablet is made in seconds, moving that many through each stage takes time.