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Effective Antacids Made With Specialty Minerals Precipitated Calcium Carbonates (PCCs)

Today’s pharmaceutical industry has developed fast acting, safe, and low-cost antacids, many of which  contain calcium carbonate as the active ingredient.


Why calcium carbonate in antacids?
Calcium carbonate is an efficient acid neutralizer that goes to work rapidly. Neutralizing the excess acid in the stomach raises the pH so these liquids are less irritating if they rise back up into the esophagus.

A second benefit is the elemental calcium brought into the body, which contributes to healthy bones and helps prevent osteoporosis. Calcium carbonate has the highest level of elemental calcium at 40 percent, so each antacid dose helps to meet the daily calcium requirement.

Finally, calcium carbonate is one of the least expensive antacid actives.


Antacid Limits and Guidelines
In the United States, antacids are normally OTC (Over The Counter) pharmaceuticals. Calcium carbonate is approved as an active ingredient in antacids, in section 21 CFR 331.10 of the Code of Federal Regulations. Each suggested single dosage unit must contain at least 5 mEq (milliequivalents) of acid neutralizing capacity. The maximum daily dosage under this regulation is 160 mEq of calcium ion, which in the case of pure calcium carbonate, corresponds to 8 grams per day. Calcium carbonate antacid tablets must disintegrate within 10 minutes and show complete dissolution within 30.

Calcium carbonate can also be used with other antacid actives in combination as long as it contributes at least 25 percent of the total acid neutralizing capacity of the product. Other countries will have similar approvals and limitations, which should be checked before formulating your antacid product.

Also in the United States, calcium-based antacids are subject to the requirements of California Proposition 65, which limits the amount of lead that can be ingested daily. One of the Learn More links below will take you to an information sheet that outlines this regulation, and how it can be met using Specialty Minerals precipitated calcium carbonates.


Antacid Dosage Forms
Consumers have a variety of forms to choose from when picking a calcium antacid. These include chewable, swallowable and effervescent tablets, liquids, soft chews, soft gels  and antacid chewing gums.

Each dosage form has different formulating parameters, which can often be difficult to meet just one simple ground calcium carbonate raw material. Specialty Minerals Inc. (SMI) has 20 pharmaceutical grade precipitated calcium carbonates, of different sizes, shapes, surface areas, and oil absorptions. With this variety, the formulator can choose the particle that gives the drug performance needed, while providing the excellent product taste consumers demand. Click on one of these links for information on the use of SMI PCCs in antacids:

  • Antacid Tablets: Chewable, Swallowable, Effervescent

  • Antacid Liquids

  • Antacid Soft Chews and Soft Gels

  • SMI Precipitated Calcium Carbonates for Antacid

     

Swallowable, Chewable and Effervescent Calcium-Based Antacid Tablets Made With Specialty Minerals Calcium Carbonates

While a number of inorganic salts—calcium, magnesium and aluminum compounds—have been used to formulate antacid tablets, calcium-based antacid tablets have become the norm. In addition to being effective acid neutralizers, calcium antacids also serve as a source of calcium, giving them a dual purpose. They are most commonly made in the form of chewable tablets, but swallowable or effervescent types can also be found. Tableted antacids are popular for occasional heartburn; they are handy to carry around, easy to take, and moderate in cost.

 

Calcium carbonate is the usual form of calcium used in these antacid tablets, and for a variety of good reasons: calcium carbonate is an effective neutralizing alkali, has a low purchase price making it economical, and provides a highly concentrated, highly bioavailable source of elemental calcium to help prevent osteoporosis.

 


Formulating Swallowable Antacid Tablets
For ease of swallowing, the tablets should be made as small as possible. To help accomplish this, Specialty Minerals Inc. (SMI) offers several types of dense and very dense precipitated calcium carbonates (PCCs). Their high densities allow the maximum antacid active to be made into a small tablet. These products, which are made in the U.S., are:

 

  • CalEssence® 450 and 1500 PCC, with particle sizes of 4.5 and 12 microns. All CalEssence® PCC products have ultra-low levels of lead, less than 125 ppb, to make compliance with California Proposition 65 easy.
  • ViCALity®  Extra Heavy and Ultra Heavy PCCs, also 4.5 and 12 microns, with less than 500 ppb, lead, which allows Proposition 65 compliance in many cases.

The best product made in the SMI’s U.K. plant for swallowable tablets is:

  • SturcalTM L PCC—a 6 micron PCC.


Formulating Chewable Antacid Tablets
When tablets are to be chewed, packing the most calcium into the smallest space is not as great a concern, so the choice of calcium carbonate type to use is broader. When the desire is to still keep tablets to a reasonably small size, the denser grades listed above are still recommended. To that list of denser grades can be added CalEssence® 300 PCC and ViCALity® Heavy PCC, both of which are 3 microns.

Others may prefer a larger tablet, so the use of a small particled PCC like CalEssence® 70 or ViCALity Albafil® PCC, each 0.7 microns, can be recommended. 

In chewable tablets, PCCs can improve the mouth texture of the product, giving the tablet a smoother feel than the gritty taste than can be encountered when some ground calcium carbonates (GCCs) are used. 


Formulating Effervescent Calcium Supplement Tablets
An effervescent tablet is an excellent option for people who don’t like to chew tablets and can’t swallow them. Calcium carbonate is an alkali, which will react with an acid which is also included in the tablet. When the tablet is dropped into water, carbon dioxide gas is formed, making the liquid bubble or effervesce. Besides being a pleasant way to take the antacid, the calcium arrives in the stomach already in a disintegrated or dissolved form for quicker relief. 

Effervescents usually contain some kind of mild organic acid, such as citric, ascorbic or malic acid. There is some technology needed to manufacture and package an effervescent that will remain stable on the shelf, and if you do not have in-house expertise, you may wish to work with a custom effervescent packager.

Many grades of SMI calcium carbonates can be used in effervescents. A smaller particle, such as the 0.7 micron CalEssence® 70 PCC or ViCALity Albafil® PCC solid particles or a slightly larger, about 2-3 micron, CalEssence® 160 PCC, ViCALity® Extra Light PCC or Calopake® Extra Light PCC needle shaped particle would be best. These PCCs have large surface areas available to react quickly with the acid, speeding up the preparation of the antacid drink, and the small particle sizes help avoid any gritty mouth feel that could result from using an overly large particle that wouldn’t fully dissolve before ingestion.

 

   ViCALity® Extra Light high surface area PCC

Granulating Calcium Carbonates For Tableting
All calcium carbonates must be granulated before converting to tablets. They have inherently poor compressibility, so are not directly compressible. This is a fundamental property of calcium carbonate, no matter the type. Granulation involves mixing the calcium carbonate with some binder such as maltodextrin, starch or acacia gum, usually at a 5 to 10 percent binder level, and then agglomerating to a larger, easier to handle particle, much like sand. 

Proper granulation is critical to producing tablets with adequate strength for handling and shipping, while also being able to disintegrate and dissolve quickly in the stomach. USP requirements for calcium carbonate antacid tablets require disintegration within 10 minutes and dissolution within 30 minutes.

SMI’s laboratory carried out a granulation study, looking at the effect of calcium carbonate particle size and particle size distribution on the granulation process and the properties of the tablets made from the granulations.

The Effect of Calcium Carbonate Particle Size and Shape on the Properties and Performance of Calcium Carbonate Granulations

Calcium carbonate is used as an active ingredient in dietary supplements and antacids, as well as an excipient in prescription and OTC (over-the-counter) drugs. Calcium carbonate has inherently poor compressibility. As a result, it is commonly combined with organic binders such as maltodextrin, starch, or acacia gum to attain adequate compressibility for inclusion in tablets. A calcium carbonate granulation is the controlled agglomeration of calcium carbonate with these binders.

Wet Granulation Study of Precipitated and Ground Calcium Carbonates
The Specialty Minerals Inc. (SMI) Consumer Products Laboratory studied the effect of calcium carbonate particle size, particle size distribution, and particle shape on the processing behavior and tableting performance of calcium carbonate granulations with maltodextrin. Using a high-shear wet granulation process, SMI tested precipitated calcium carbonates (PCCs) having four different shapes and ranging in particle size from 0.8 to 12 microns, as well as a ground calcium carbonate (GCC), 3.5 microns in size.

The study concluded that:

  • The granulation process and granulation physical properties are most affected by calcium carbonate particle size and particle size distribution.

  • Calcium carbonate morphology has the greatest impact on granulation tableting properties and tablet performance.

  • PCC provides granulations with greater porosity.

  • PCC imparts faster disintegration than GCC, as well as superior dissolution at the 10 percent binder concentration commonly used in commercial granulations.

  • Lower-bulk density, higher-surface area PCCs (scalenohedrals) produce the most porous and smooth textured granulations.

  • Granulation properties and performance of granulations made with scalenohedral PCCs can be improved with the addition of a higher density rhombohedral-shaped particle.

  • The rapid disintegration achieved with PCC would be advantageous for effervescent and quick-dissolve tablets.

  • Smooth granulation texture achieved with smaller-size PCC, even at low binder levels, is advantageous for tablet applications where palatability or mouth feel is important.  Suggested applications are chewable and quick-dissolve tablets.

  • PCC, with its different particle morphologies and broad choice in particle sizes, provides the greatest flexibility in creating granulations with specific, targeted tableting performance properties.

Specialty Minerals Precipitated Calcium Carbonates for Granulations

  • Rhombohedral: ViCALity® Heavy, CalEssence® 450 and ViCALity® Ultra Heavy PCCs.  These are 3.0, 4.5 and 12.0 microns in size. The ViCALity® PCC grades have low levels of lead, less than 500 ppb (parts per billion), while the CalEssence® PCC grades have ultra-low levels of lead, less than 125 ppb. Each of these families have products that are 3.0, 4.5 and 12.0 microns. The ViCALity® PCC equivalent to CalEssence® 450 PCC is ViCALity® Extra Heavy PCC. The CalEssence® PCC equivalent to ViCALity® Heavy PCC is CalEssence® 300 PCC, and to ViCALity® Ultra Heavy PCC is CalEssence® 1500 PCC. Larger-sized SMI PCC particles are also produced in Europe under the Sturcal™ PCC trademark.

  • Scalenohedral: ViCALity® Extra Light PCC has an open structure formed from calcite needles, with high surface area and high oil absorption. The CalEssence® PCC family equivalent is CalEssence® 160 PCC. This type of product is also made by SMI in Europe: Calopake® Extra Light PCC.

  • Smaller-sized PCC: ViCALity Albafil® PCC, a 0.7 micron prismatic particle, and ViCALity Albaglos® PCC, an 0.8 micron product that is ViCALity Albafil® PCChas 15 percent of ViCALity® Heavy PCC added to improve powder flow and water slurry viscosity. Both can be used in tableting. The CalEssence® PCC family equivalents are CalEssence® 70 PCC and CalEssence® 80 PCC.

The ViCALity® and CalEssence® PCCs are manufactured in SMI’s plant in Adams, Massachusetts, and the Calopake® PCC is manufactured in SMI’s plant in Birmingham, U.K. All meet the local Pharmacopeia and food additive requirements and are certified Kosher.

Additional information on the use of these PCCs in nutritional supplement, antacid, and pharmaceutical applications can be found by clicking on one of these links:

  • PCCs for nutritional supplement tablets

  • PCCs for antacid and other pharmaceutical tablets

  • Granulating calcium carbonates

Swallowable, Chewable and Effervescent Calcium Nutritional Supplement Tablets Made With Specialty Minerals Calcium Carbonates

Tablets, whether swallowable, chewable or effervescent, are among the most common types of calcium supplements. These supplements are easy to take, moderate in cost, and can readily be included in a daily vitamin/mineral supplement regimen.

Calcium carbonate is the usual form of calcium used in these dietary supplement tablets for a variety of reasons: calcium carbonate has the highest concentration of elemental calcium, 40 percent is significantly less expensive than other calcium salts, which makes it most economical in use; and calcium carbonate is highly bioavailable.

 

Formulating Swallowable Calcium Supplement Tablets
The RDI (Recommended Daily Intake) of elemental calcium by adults in most countries is 1,000 milligrams of calcium per day. For optimal calcium absorption health experts recommend that the daily intake be divided into two or three smaller doses throughout the day.

The tablets should be made as small as possible for ease of swallowing. Calcium carbonate facilitates production of the smaller tablets. With its 40 percent level of elemental calcium, 2,500 milligrams of calcium carbonate will provide the needed 1,000 milligrams of calcium. In contrast, when calcium citrate is used, which is only 21 percent elemental calcium, 1.9 times as much—4,800 mg—is required to provide the same 1,000 mg of calcium.

To aid in making the smallest possible tablets, Specialty Minerals offers several types of dense and very dense precipitated calcium carbonates (PCCs), which allow maximum calcium loading in a small tablet. These products, which are made in the U.S. are:

  • CalEssence® 450 and 1500 precipitated calcium carbonate, with particle sizes of 4.5 and 12 microns. All CalEssence PCC products have ultra-low levels of lead, less than 125 ppb, to make compliance with California Proposition 65 easy.

  • ViCALity® Extra Heavy and Ultra Heavy PCCs, also 4.5 and 12 microns, with less than 500 ppb of lead, which allows Proposition 65 compliance in most cases.

The best product for swallowable tablets, which is made in the Specialty Minerals plant in the United Kingdom, is:

  • Sturcal® L PCC – a 6 micron PCC.

Formulating Chewable Calcium Supplement Tablets
When tablets are to be chewed, packing the most calcium into the smallest space is not as great a concern, so the choice of the type of calcium carbonate is broader. When the desire is to still keep tablets to a reasonably small size, the denser grades listed above are still recommended. To that list of denser grades recommended for swallowable tablets, CalEssence 300 PCC and ViCALity Heavy PCC, both of which are 3 microns, can be added to the recommendations for chewables.

Others may prefer a larger tablet, so the use of a small particled PCC like CalEssence 70 or ViCALity Albafil® PCC, each 0.7 microns, can be recommended. As when preparing swallowable tablets, any calcium carbonate chosen must be granulated before compression into a tablet.

Formulating Effervescent Calcium Supplement Tablets
An effervescent tablet is an excellent option for consumers who don’t like to chew tablets and can’t swallow them. An effervescent tablet can be prepared with a variety of liquids—water, juice, soft carbonated beverages. Calcium carbonate is an alkali that will react with an acid, which is also included in the tablet.  When the tablet is dropped into the liquid, carbon dioxide gas is formed, making the liquid bubble or effervesce. Besides being a pleasant way to take the supplement, the calcium enters the stomach dissolved so it can be more quickly absorbed. The reaction also reduces and buffers the pH of the liquid, making it more tolerable on the stomach.

Effervescents usually contain some kind of mild organic acid, such as citric, ascorbic or malic acid. Some technology is needed to manufacture and package an effervescent so it will remain stable on the shelf and may require the formulation expertise of a custom effervescent packager.

Many grades of SMI calcium carbonates can be used in effervescents. A smaller particle, such as the 0.7 micron CalEssence 70 PCC or ViCALity Albafil PCC solid particles or a slightly larger, about 2-3 micron, CalEssence 160, ViCALity Extra Light or Calopake™ Extra Light PCC needle shaped particle would be best.  These PCCs have large surface areas available to react quickly with the acid, speeding up the preparation of the drink. And the small particle sizes help avoid any gritty mouth feel that could result from using a overly large particle that wouldn’t fully dissolve before ingestion.

Granulating Calcium Carbonates For Tableting
All calcium carbonates must be granulated before converting to tablets, as they have inherently poor compressibility, so are not directly compressible. This is a fundamental property of calcium carbonate, no matter the type. Granulation involves mixing the calcium carbonate with some binder such as maltodextrin, starch or acacia gum, usually at a 5 to 10 percent binder level, and then agglomerating to a larger, easier to handle particle, much like sand. 

Proper granulation is critical to producing tablets with adequate strength for handling and shipping, while also being able to disintegrate and dissolve quickly in the stomach. USP requirements for calcium carbonate supplement tablets require disintegration and dissolution within 30 minutes.

Specialty Minerals’ laboratory carried out a granulation study, looking at the effect of calcium carbonate particle size and particle size distribution on the granulation process and the properties of the tablets made from the granulations. Study on talc lubricity shown below.

Specialty Minerals Precipitated Calcium Carbonates For Nutritional Supplement Tablets

All Specialty Minerals precipitated calcium carbonates are manufactured in plants registered with the U.S. Food and Drug Administration (FDA) as Drug Manufacturing Establishments, and follow Good Manufacturing Practices (GMP). These plants are also ISO 9000 quality certified.

The CalEssence and ViCALity PCC products are made in Adams, Massachusetts and are certified to meet USP and FCC requirements. The Sturcal™,  Calopake™, Multifex-MM® USP, and Calofort® U PCCs are manufactured in the United Kingdom. They are certified to meet EP, USP and E170i requirements, and can be certified to meet USP / FCC, as well.  All are certified Kosher, and are available world-wide.


Specialty Minerals Talcs As Tablet Glidants and Lubricants
SMI also manufactures USP talcs which are used in tableting as glidants and lubricants. Small particle sized talcs, 2 to 3 microns, are normally used. When one of these small talcs replaces a portion of the magnesium stearate that is used for lubrication, the disintegration and dissolution times impaired by the addition of magnesium stearate can be restored. 

The two Specialty Minerals talcs recommended for use in tableting are MicroTalc® MP 15-38 USP talc and  UltraTalc® 5000 USP talc.

Specialty Minerals Precipitated Calcium Carbonates (PCCs) For Antacid Tablets
Use the product-application selector chart above to guide your selection of a Specialty Minerals PCC for your antacid tablet.

All SMI’s precipitated calcium carbonates are manufactured in plants that are registered with the U.S. Food and Drug Administration (FDA) as Drug Manufacturing Establishments, and follow Good Manufacturing Practices (GMP). These plants are also ISO 9000 quality certified.

The CalEssence® and ViCALity® PCC products are made in Adams, Massachusetts and are certified to meet USP and FCC requirements. The Sturcal™, Calopake®, Multifex-MM®, and Calofort® U PCCs are manufactured in Birmingham, U.K. They are certified to meet EP, BP and E170i requirements, and can be certified to meet USP / FCC, as well. All are certified Kosher, and are available world-wide.

Specialty Minerals Talcs As Tablet Glidants and Lubricants
SMI also manufactures USP talcs which are used in tableting as glidants and lubricants. When the proper particle size talc is chosen in relation to the sizes of the other ingredients, disintegration and dissolution times impaired by magnesium stearate lubricant can be improved.

Particle Size Effect On Talc Lubricity

Specialty Minerals Inc. (SMI) manufactures USP talcs for pharmaceutical and nutritional supplement tablet production. The platy nature of talc, the slipperiness that results from its crystalline structure, its softness and hydrophobicity all contribute to its performance as a glidant and lubricant in tableting.

Talc as a Tablet Glidant and Lubricant
The SMI Healthcare Laboratory carried out a study of the performance of different SMI talcs as glidants (to help powder flow to the tablet die) and lubricants (to ease the ejection of the tablet from the die). Talcs of different particle sizes, made from two types of talcs, were added at a 5 percent level to a spray-dried lactose monohydrate, and the flow properties of the blends were then measured. Next, they were blended into a compression tablet mixture based on dibasic calcium phosphate dihydrate and the lactose, and then tableted. The results were presented at a Poster Session at the 2004 American Association of Pharmaceutical Scientists Annual Meeting.

The conclusions of the study were:

  • The effectiveness of talc glidant activity is dependent upon particle size compatibility between the talc and the other powders in the formulation.

  • Talc lubricant efficiency in plastic deforming binders/fillers increases with decreasing talc particle size and increasing talc surface area.

  • Very large talcs that greatly improve powder flow may not allow the formation of tablets at all.

  • Talc improves direct-compression tablet-formulation disintegration behavior, which is independent of particle size.

  • Talc can be used effectively in combination with magnesium stearate to restore disintegration and dissolution properties impaired by magnesium stearate.

  • Talcs around 2.5 microns in size gave the best overall performance in tableting.

     

Click here to download a set of PowerPoint slides with the details of materials, methods, and tableting results, including compression and ejection profiles.

Specialty Minerals Talcs For Tablet Glidants and Lubricants
Talcs typically used as both lubricant and glidant are 2 to 3 micron fine talcs. SMI has two such talc products, Microtalc® MP 15-38 USP talc, which is 2.0 microns, and UltraTalc® 5000 USP talc, which is 2.5 microns in size.