Size matters with capsules. It relates closely to dosage, swallowability, formulation, manufacturing, and packaging. Pharmaceutical manufacturers must know about capsule sizes.
Among capsule sizes available, sizes 00 and 0 are the most commonly used options. Which size is bigger, 00 or 0? This post will reveal nuances of the differences between them.
What Are Capsule Sizes?
Capsule sizes refer to the dimensions and volumes of empty capsules. In simple terms, they tell how big an empty capsule is and how much content it can accommodate. Though capsules have different sizes, they have been standardized.
Today, standard capsule sizes are #000, #00, #0, #1, #2, #3, #4, and #5. What do these numbers mean? The smallest numbers are the largest sizes of capsules, and vice versa. For example, size 000 stands for the biggest capsule, and size 5 is the smallest one. Simply memorize in reverse.
Why Are Capsules Available in Different Sizes?
Here are some of the reasons.
- Dosage Flexibility: Different sizes allow for precise control over the amount of medication. This ensures patients get the correct dose.
- Patient Comfort: Not everyone can swallow large capsules. Smaller capsules are easier to swallow, especially for children and elderly patients.
- Medication Type: Some medications need larger capsules to fit the required amount. Others, like highly potent drugs, need only a small capsule.
- Combination Pills: Sometimes, capsules need to hold a combination of different medications. Larger sizes can accommodate these combinations.
- Manufacturing Needs: Different ingredients might take up more or less space. Capsule size helps manage the volume of different components.
- Release Control: Some capsules are designed for extended or delayed release. The size can influence how the medication is released in the body.
Standard Capsule Size Chart
Knowing the capsule size chart helps in getting an idea about sizes. This includes size specifications, volume capacities, and formulation density of each option.
| Capsule Size | 000 | 00 | 0 | 1 | 2 | 3 | 4 | 5 |
| Volume (ml)* | 1.27 | 0.9 | 0.68 | 0.48 | 0.36 | 0.27 | 0.2 | 0.13 |
| Overall Length (mm)* | 26.1 | 23.4 | 21.6 | 19.4 | 17.6 | 15.7 | 14.3 | 11.1 |
| Formulation Density (mg)* | ||||||||
| 0.6 g/ml | 822 | 540 | 408 | 288 | 216 | 162 | 120 | 78 |
| 0.8 g/ml | 1096 | 720 | 544 | 384 | 288 | 216 | 160 | 104 |
| 1.0 g/ml | 1370 | 900 | 680 | 480 | 360 | 270 | 200 | 130 |
| 1.2 g/ml | 1644 | 1080 | 816 | 576 | 432 | 324 | 240 | 156 |
*Volume (ml): This refers to how much space is inside a capsule, measured in milliliters (1 ml = 1 g). Think of it like the amount of ingredients the capsule could hold.
*Overall Length (mm): This is the full length of a capsule when it's completely closed and locked, measured in millimeters.
*Formulation Density (mg): This is about how much a capsule can hold based on the weight of your specific formulation. It's measured in milligrams and depends on how dense your formulation is.
Which Capsules Are Bigger, 0 or 00?
So, if you want to know which capsule is bigger, #0 or #00, the answer is given in the chart above.
- Size and Volume
As shown in the chart, Size 00 capsules are bigger. They can hold about 0.90 ml of content inside, while Size 0 capsules can hold around 0.68 ml. So, if you need more room, Size 00 is your go-to.
- Weight Capacity by Formulation Density
Because they're larger, Size 00 capsules can also carry more weight. For example, if your formulation has a density of 1.0 g/ml, Size 00 can hold up to 900 mg. Size 0 will only handle 680 mg.
- Length
When it comes to length, Size 00 capsules are a bit longer. They are generally at 23.4 mm, while Size 0 is 21.6 mm. Not a huge difference, though.
- Diameter
Size 00 capsules are a little wider, too. The cap has a diameter of 8.56 mm, and the body is 8.23 mm. Size 0's cap is 7.64 mm wide, with the body at 7.35 mm.
- Quantity Per Case
For packaging, each box can come with 75,000 capsules for Size 00 and 100,000 capsules for Size 0. So, you get more capsules in a box if you go with Size 0.
In summary, Size 00 capsules are larger and can hold more, making them perfect for bigger doses. On the other hand, Size 0 capsules are smaller, which might be easier to swallow, and are packaged in greater quantities.
Types of Capsules Available in Sizes 0 and 00
#00 and #0 are the most popular capsule sizing options. Many different types of capsules are available in these two sizes. You can typically find gelatin, vegetarian, pullulan, and enteric capsules.
- Gelatin Capsules
These capsules are made from animals like pigs, cows, and fish. They are easy to swallow and break down very quickly in your stomach.
- Vegetarian Capsules (HPMC)
These are made with Hydroxypropyl Methylcellulose. This plant-based substance is stable over a pH range of 2-12. If you're vegetarian or vegan, HPMC capsules are an excellent choice.
- Pullulan Capsules
These capsules come from pullulan, a natural polysaccharide fermented from tapioca. They help protect oxygen-sensitive ingredients. Plus, pullulan capsules are vegan-friendly and free from gluten, preservatives, and starch.
- Enteric Capsules
These have an enteric coating. The coating is a special polymer that ensures the ingredients inside the capsules survive in the stomach acid but dissolve in the intestines. They are ideal for probiotics, enzymes, and certain medications.
Which to Choose: Capsule Size 0 vs 00
So, which one should we pick between sizes 0 and 00? Here are a few questions you can ask yourself first.
Q: How Much Do You Want to Fill?
Estimate the amount of ingredients you have to fill in the capsule. Size 0 capsules typically contain between 408 mg and 816 mg of powders. The amount you can get into a Size 00 pill is around 540 mg to 1080 mg.
Q: Who's Taking the Capsule?
Who will be taking these pills? This is super important. Most people do just fine with Size 0 capsules, as they are smaller and usually easier to swallow. If you are aiming for children or the elderly, Size 00 capsules can be a bit large and harder to swallow for them.
Q: What's the Serving Size of Your Capsule Product?
Lastly, we come to the dosage, aka the serving size, of APIs in one capsule. If you need a larger dose, Size 00 capsules will likely be your best bet since they can hold more volume. The best-suited size for lower or moderate serving sizes is #0. If the required dose of APIs is too large for the size you're considering, go for a larger size or distribute the dose over the capsules with a smaller size.
The Bottom Line
Comprehending the differences between capsule size 0 vs 00 matters. Even though the distinction is very subtle, it's still essential for pharmaceutical and nutraceutical manufacturers to keep in mind. Choosing the smaller Size 0 or the larger Size 00 depends on your product, consumers, and regulatory compliance.