Weighing the Choices in Encapsulation

by Heather Granato

Nutraceutical ingredients can be delivered in myriad forms.There are powders, liquids, tablets, capsules, bars, beverages and much more.The functional food category holds the promise of opening up nutrientenhancement to a wider array of consumers. However, there are certainlimitations to every delivery system, as well as special benefits a manufacturergains from each process.

Hard-shell capsules are a popular delivery system for manybotanicals, while softgels have an increasing market in the area of oilyproducts such as vitamin E and essential fatty acids (EFAs). Capsules are notlimited to only a gelatin exterior, as innovations in production are yieldingvegetarian alternatives to the primarily bovine encapsulation source.

Currently, many more manufacturers offer hard-shellencapsulation, and a majority of capsule products are delivered in this moretraditional form. "The market for nutritional products in hard-shellcapsules is obviously much larger than that of soft-shell capsules, bothdomestically and overseas, as there are more manufacturers in the hard-shellbusiness," said Rezaur R. Yousuf, director of business operations for KabcoInc., Amityville, N.Y. "Of course, many soft shell encapsulators are doingOTC [over the counter] products, which is perhaps more profitable than mostnutritional products."

Softgel encapsulation produces a smooth--often clear--exteriorengulfing the ingredients within. "Soft capsules are generally consideredto be a premium dosage form," said Robin Koon, vice president ofsales/marketing for Best Formulations, City of Industry, Calif. "They areeasier to swallow and offer a point of differentiation. They also don't have thetaste issues that can occur with hard capsules."

Softgels are generally best for oil-based or liquid products, asmentioned previously. In particular, because of total encapsulation, softgelsoffer more protection to oxygen-susceptible ingredients. Oxidized ingredients,as well as some more pungent natural compounds, carry strong scents that gelatincoating can also quash. For example, fish oil encapsulated in gelatin tends tohave less of an odor than a dried fish oil powder in a hard capsule.

Another benefit to softgels is enhanced bioavailability of someproducts, according to Nehru Gaddipati, Ph.D., president of Somerset, N.J.-basedStrides Inc. "A classic example is the solubilized formulation of coenzymeQ10 (CoQ10), which has been shown to have better bioavailability than thehard-shell capsules," he said.

However, softgel encapsulation is not without its difficulties.Koon said some of the difficulties include developing innovative products,maintaining high quality standards and providing competitive pricing. Otherindustry members add because softgel encapsulation is a semi-automatic processthat requires oversight, it often means running a multi-shift operation with theadded costs that entails. "Soft-shell encapsulation is, perhaps, moresophisticated than hard-shell encapsulation, with very little room forerror," Yousuf said.

Hard-shell encapsulation, on the other hand, has been in uselonger, and can be run automatically and at greater rates of speed. Mostcontract manufacturers offer hard-shell encapsulation services, though some aremore concentrated than others in that area. NHK Laboratories, for example,specializes in filling two-piece hard-shell capsules. "We recently added anew high-speed Bosch encapsulation line to better accommodate large runs,"said M. Amirul Karim, president of the Santa Fe Springs, Calif.-based company.It has also developed technology to enteric coat two-piece capsules for atime-release effect.

Generally, hard-shell encapsulation permits a wider range ofingredients to be used. Most botanicals, vitamins and minerals can be used inthe process. "If we can ensure stability of a formula in a two-piececapsule, and we deem it feasible to manufacture using dry powders, we advise ourclients that the two-piece capsule is an appropriate dosage form," Karimsaid. "It boils down to the stability and feasibility of the product."

Hard-shell encapsulation does pose its own set of challenges.Because of the set capsule size, adding too much or too little of an ingredientor formula is a challenge to be addressed at the beginning of a process."If we have to encapsulate a multi-ingredient product that contains somehygroscopic material, it can become a nightmare," Yousuf said. "Or acustomer will want a single ingredient in a capsule that does not have therequired density to meet the fill weight."

The density issue is particularly difficult with botanicals."Herbal extracts have lower densities than other ingredients, such as coralminerals or MSM," Karim said. "Due to the lower density, it becomesdifficult to fill several hundred milligrams of any given herbal extract into atwo-piece capsule. Along with density is the flowability factor. Herbal extractsby nature are 'sticky' and do not have good flow characteristics. This makesproducing the product very time consuming and difficult."

In fact, many herbs have long been available as herbaltinctures. Extraction in water or alcohol, depending on the botanical, maximizesdelivery of active components. However, the taste aspect has kept many consumersaway from liquid extracts, driving demand for encapsulated products.

Some manufacturers are finding ways to merge consumers' desirefor a liquid product with the manufacturing capabilities of hard-shell capsules.Capsugel and LiquidCeuticals both offer HPMC two-piece hard-shell capsules thatare band-sealed. "Band sealing of capsules minimizes leakage issues andincreases the tamper resistance of all two-piece capsules," said FredMiller, marketing director for LiquidCeuticals in Clearwater, Fla.

"Natural vitamin E or any natural oil combination in anHPMC capsule can be all-natural because the delivery form does not require anybinders, fillers, excipients or plasticizers that are common with many soft geldelivery forms. Liquid filled capsules are a very visually appealing productbecause consumers can easily see the material they are ingesting."

Before it launched its Licaps product in 2001, Greenwood,S.C.-based Capsugel conducted a nationwide product concept test toquantitatively measure consumer interest in a two-piece liquid-filled capsule.Their findings confirmed that consumers connected their perceived benefits ofliquids with the Licaps supplements. Of those surveyed, 74 percent ofparticipants who chose Licaps said they would purchase their supplements in thatdosage form, if it was available.

In addition, HPMC capsules used in these systems are vegetarian,meeting a rising consumer trend. Many contract manufacturers report increasedinterest in vegetarian formulas and delivery systems. "We have noticed atremendous growth in vegetarian capsules," confirmed Jay Kaufman, presidentof Torrance, Calif.-based Paragon Laboratories. "More customers arerequesting capsules from a vegetable source."

Whether vegetarian or gelatin, marketers are turning to expertsin the field when deciding what system to use for encapsulation. "Certainmolecules are more appropriate for hard versus soft encapsulation due to severalfactors related to the internal formulation's reaction to the shell," saidRobert Whitelaw, director of sales/marketing for Capsugel. "There is adifference in the oxygen permeability of hard gelatin capsules as compared tosoft gelatin capsules. Some formulations are more odorous or have a strongtaste. Those formulations, when compatible for use with hard gelatin capsules,are usually best encapsulated in hard gelatin capsules because the smallermatrix of the HGC shell provides greater masking of odor and taste. Otherfactors, including the ratio of water and/or alcohol, also affect the decision.These factors are precisely why it is important to partner with a capsulesupplier who can provide formulation information and support as part of thepartnership."

After considering the issues, many marketers are choosing tooutsource capsule production. "It comes down to cost, volume andknowledge," Koon said. "The cost of installing and running a softgelfacility is high. Since these machines run much slower than tablets or two-piecehard-shell capsules, attention must be made toward efficiencies."

Even marketers who have the capability for producing hard-shellcapsules may look for an expert in the softgel field, Gaddipati said."Manufacturing of softgels is still considered an art because the productquality is dependent on a skilled operator that can understand the viscoelasticproperties and sealing characteristics of gelatin," he added."Contract manufacturing facilities usually have the knowledge andunderstand the intricacies of formulation to troubleshoot any manufacturingissues in a timely manner."

The efficiencies come down to savings of dollars, which can thenbe put toward marketing instead of product development. "A customer who issuccessfully marketing a product, be it hard-shell or soft-shell capsules, neednot go into the manufacturing process," Yousuf said. "It is not onlytoo expensive but may also be a difficult proposition to manage, especially whenhis products are already being marketed well."