Statement on Additives (Excipients)
HPDI allows our manufacturers to use certain excipients in the preparation of our nutritional supplements. This statement refers to the primary excipients we allow, all of which derive from natural ingredients, are known for their safety, and are GRAS listed.
HPDI Rationale For Excipients
In any nutritional product we sell, we permit a minimum amount of necessary additives/excipients that may include fillers, flow agents/glidants, lubricants, coloring agents, binders, or disintegrants. This policy applies to products in the HPDI label, the Hank & Brian’s label, and the Pathway label. We require our manufacturers to minimize or eliminate the use of excipients. We also continue seeking manufacturers with equipment, knowledge, and willingness to support our longstanding policy of minimizing excipients.
We specifically do not allow the use of the following excipients in the manufacture of our products:
- dicalcium phosphate
- white rice powder
When Excipients Are Necessary
The correct amount and kind of additives/excipients are often essential for product effectiveness. Some of the reasons for including excipients include:
When additives/excipients are an integral part of a product delivery system.
Controlling release of active ingredients at proper sites in the body for optimal assimilation.
Providing for disintegration of a product into small particles for proper absorption.
Protecting the stability of a product so that it is effective at the time it is used.
Filling excess space in a capsule or die.
Supporting uniform mixtures and proper dosages for capsules, tablets, softgels, or powders.
Allowing for release of a product from manufacturing equipment.
Excipients Allowed by HPDI
There are several excipients that we generally allow our manufacturers to use in our capsule and tablet products. These include:
1) Microcrystalline Cellulose (GRAS listed) - Microcrystalline Cellulose is a naturally occurring substance proven to be stable, safe and physiologically inert. Microcrystalline Cellulose is cellulose derived from high-quality wood pulp. While cellulose is the most abundant organic material in the pulp, microcrystalline cellulose can only be derived from alpha cellulose.
Microcrystalline cellulose revolutionized tabletting because of its unique characteristics. It exhibits excellent properties as an excipient for solid dosage forms. It compacts well under minimum compression pressures and offers high binding capacity. It enables production of tablets that are extremely hard and stable, and yet which can disintegrate rapidly when consumed. Other advantages include low friability, inherent lubricity, and the highest dilution potential of all binders. These properties make microcrystalline cellulose particularly valuable as a filler and binder for formulations prepared by direct compression, although it also is used in wet or dry granulation.
2) Silica / Silicon Dioxide (GRAS listed) - Silicon Dioxide is widely used in pharmaceutical formulations, cosmetics, and food products. It is also widely used in orally-dosed nutritional products and regarded as an essentially nontoxic, nonirritant excipient. Silicon dioxide readily absorbs large quantities of water from its surroundings, and does this without itself liquefying. The major application of silica in solid-dosage forms is as a glidant and anti-static agent to improve the flow properties of granulations in high-speed tablet and capsule machines. Particulate flow has a direct effect on weight uniformity and plays an important role in solid-solid blending and powder homogeneity.
Glidants reduce friction between particles and function to improve the flow of granulations in the manufacturing process. Silica also fills surface irregularities in granules, reducing inter-particulate friction and improving flow. Glidants also prevent the segregation and separation of granules caused by excessive vibration in a tablet press or capsule press. The presence of silica in a tablet granulation prevents cavitation or surging of the powder blend that often occurs in direct compression formulations. Uniformity in tablet hardness and tablet weight results from formulations flowing evenly into the die cavity during tabletting operations. Silica is generally used as a glidant at a concentration range of 0.1%–0.75%, and is typically used at the 0.5% level.
3) Magnesium Silicate (GRAS listed) – Magnesium silicate is used in oral nutritional formulations and food products as a glidant, and is generally regarded as an essentially nontoxic and nonirritant material. The US Pharmacopeia (USP) describes Magnesium silicate as a compound of magnesium oxide and silicon dioxide with varying proportions of water. It contains not less than 20% of magnesium oxide and not less than 45% of silicon dioxide. Magnesium silicate occurs as an odorless and tasteless, fine, white-colored powder that is free from grittiness, and is practically insoluble in water. When administered orally, magnesium silicate is neutralized in the stomach to form magnesium chloride and silicon dioxide; some magnesium may be absorbed. Whenever possible we use magnesium silicate in combination with silica as a replacement for magnesium stearate. Magnesium silicate is generally used as a glidant in a concentration range of 0.1%–0.75%, and is typically used at the 0.5% level.
4) Magnesium Stearate/Stearic Acid (GRAS listed) – Magnesium stearate (also known as octadecanoic acid) is a white magnesium salt that is solid at room temperature. It has the chemical formula C36H70MgO4. It is a salt containing two equivalents of stearate (the anion of stearic acid) and one magnesium cation (Mg2+). Stearic acid is a saturated 18 carbon chain fatty acid that is frequently found in meats as well as plant foods. The highest-quality vegetable based magnesium stearate we use in some of our formulations contains 92%–97% stearate with trace amounts of palmitate, a saturated 16-carbon chain fatty acid frequently found in foods. Due to its high stability it is unlikely that the body absorbs any of the magnesium stearate in a supplement formulation. Stearic acid itself, In supplement dosage forms, is used as an emulsifying agent, solubilizing agent, tablet and capsule lubricant.
Magnesium stearate melts at about 88°C, is not soluble in water, and is generally considered safe for human consumption (GRAS). Because it is widely regarded as harmless, it is often used as a filling agent in the manufacture of nutritional and pharmaceutical formulations. Magnesium Stearate serves as an efficient lubricant for mold release purposes during tabletting processes. Its hydrophobic (i.e., water-repelling) properties prevent finished products from absorbing water and improve flowability during capsule filling.
Magnesium stearate is typically used in a concentration range of 0.25%–2%. Higher values can result in decreased absorption of the product. We consequently limit magnesium stearate concentrations in our formulations to 1% or less. Whenever possible, we encourage our manufacturers instead to utilize silica and magnesium trisilicate at slightly higher levels in order to obtain the necessary lubricating/glidant effects. In most capsule formulations this works well. However, in tablet manufacture it is generally necessary to use magnesium stearate at the 1% concentration in order to enable tablet release from molds. In a few cases where an encapsulated product is greatly hydroscopic (i.e., water-absorbing) (such as l-carnosine and acetyl-l-carnitine), it is necessary to utilize up to 1% magnesium stearate in order to block excess moisture uptake leading to poor or uneven capsule filling.
5) Ascorbyl Palmitate (GRAS listed) - Ascorbyl palmitate is used primarily as a lubricant; it improves the flow of tableting powders in the presses during manufacture and facilitates ejection of tablets from the equipment following compression. Ascorbyl palmitate is generally used at the level of 0.05%. While more costly than standard lubricants, ascorbyl palmitate (a fat-soluble form of vitamin C) also provides some additional vitamin C activity. It is often used to replace the excipient magnesium stearate.