Novel stable beadlets of lipophilic nutrients

Abstract

The invention disclosed in this application relates to novel stable beadlets of lipophilic nutrients comprising an inert core having a coating of stabilizing antioxidants, lipophilic nutrients, or mixtures thereof. The beadlets may be coated with one or more coatings to protect the lipophilic ingredients from the atmosphere, specifically the coatings can be used to protect against moisture and / or oxygen. The invention also relates to a process for the preparation of the stable beadlets. The beadlets can be used in medicines and dietary supplements intended to facilitate the reduced risk of macular degeneration, cataract, and several forms of cancer.

Description

[0001]This application is a Division of application Ser. No. 10 / 901,748, filed Jul. 29, 2004, which application is incorporated herein by reference.[0002]The present invention relates to novel beadlets of lipophilic nutrients and a process for their preparation. The present invention, particularly relates to novel and stable beadlets of lipophilic nutrients, materials, or substances, particularly nutrients like carotenoids, tocopherols, tocotrienols, plant sterols and stanols, and lecithins, select omega-3 fatty acids and poly-unsaturated fatty acids, more particularly novel beadlets of lutein, lutein esters, zeaxanthin, zeaxanthin esters, and a process for their preparation.BACKGROUND OF THE INVENTION[0003]The role of nutrients and phytochemicals in the promotion of good health through nutrition has now been extended to the likely benefits such as prevention of cancer, and protection against many other chronic diseases like arthritis, coronary heart disease, osteoporosis, and possi...

AI Technical Summary

Benefits of technology

[0038]The spherical nature of the beadlets has several advantages such as, free flowing property which is required during tablet compression, enables compression of tablets using a compression force as high as 10 kg / cm2, superior release property, possibility of site specific controlled release of carotenoids and lipids, and consequently, higher bioavailability. The major advantage of using such technology is that it avoids the use of high temperature (above 50 degree C.) during preparation of beadlets and thus prevents degradation of heat-sensitive bioactive compounds. Another advantage of using spherical cores is the broader range of beadlet size which can range between about 250 microns to about 3.50 mm. The beadlet size can also be from about 250 microns to about 2.0 mm. Another advantage of the present invention is that the invention can be practiced using existing fluid-bed technology and equipment.

[0039]Accordingly, the present invention provides novel stable beadlets of lipophilic nutrients, which comprise an inert core having a coating of a mixture of stabilizing antioxidants and a lipophilic nutrient or mixtures thereof.

[0040]The novel beadlets of the present invention are obtained by coating one lipophilic nutrient, or a mixture of such nutrients on a central inert core to obtain uniform, generally spherical beadlets. The uniform, generally spherical, appearance of these beadlet provides excellent free flowing characteristics, which are very desirable for manufacturing and formulating operations. These novel beadlets are convenient to use, and have a stronger visual appeal. The novel beadlets of the present invention also may be stabilized synergistically with the use of anti-oxidants and with the application of layers of polymeric materials as coatings, preferably gelatin free, on the beadlets as barriers to prevent penetration of light, moisture and / or air. The beadlets of the present invention are well suited for use as directly compressible ingredients in tablets, or in two-piece capsules.

[0041]In one embodiment of the present invention the inert core may be comprised of any material that does not react with the lipophilic nutrient or carotenoid employed for coating. It can be selected from non-pareil seeds made of carbohydrates such as sugar, mannitol, starch, sago, or microcrystalline cellulose. More preferably, the core used may be seeds such as sugar spheres, mannitol spheres, or the like. The inert core can generally be in the form of a sphere, and can have a diameter from about 200 microns to about 3 mm and still yield a stable beadlet. The inert core can also have a diameter of about 200 microns to about 1.5 mm.

[0042]One embodiment of the current invention includes lipophilic nutrients in the coating. Lipophilic nutrients refers to a class of compounds that show an affinity towards oily or fatty solvents or carriers, such as hexane, or otherwise have a higher solubility in hydrocarbons than water, and may be used in the current invention. The beadlets can comprise from about 1 wt. % to about 50 wt. % lipophilic nutrient.

[0043]In one embodiment of the present invention the lipophilic nutrients used in the coating are carotenoids, tocopherols, tocotrienols, plant sterols and stanols, and lecithins, select omega-3 fatty acids, and poly-unsaturated fatty acids, or mixtures thereof. The lipophilic nutrients may comprise carotenoids such as lutein, lutein esters, zeaxanthin, alpha-carotene, beta-carotene, natural lutein or zeaxanthin esters, astaxanthin, or lycopene. The beadlets can contain a mixture of these substances as well. For instance, the stable beadlets can comprise xanthophyll esters containing lutein and zeaxanthin fatty acid esters in which about 90 wt. % to about 95 wt. % is trans-lutein esters, 0 wt. % to about 5 wt. % is cis-lutein esters and about 3.5 wt. % to about 6 wt. % is zeaxanthin esters. The beadlets can also comprise xanthophyll crystals that comprise at least about 85 wt. % total xanthophylls in which at least about 90 wt. % is trans-lutein and / or zeaxanthin.

Problems solved by technology

Lipophilic substances have a higher solubility in hydrocarbon solvents, such as hexane, and have poor water solubility.

It is a major problem for formulators and manufacturers of such supplements to incorporate lipophilic nutrients such as carotenoids, vitamin E sources like tocopherols and tocotrienols, concentrated forms of PC-rich lecithins, phytosterols and plant stanols, various PUFA rich oils and omega-3 fatty acids singly or in combination with other nutrients into dry forms due to the oily, waxy or viscous nature of these products.

Some options like spray dried powders, granules or gelatin beadlets work only with select products, and do not necessarily function well under tabletting systems.

Some of the challenges in using lipophilic nutrients are explained below:a. Carotenoids tend to be unstable at room temperature, and prone to degradation on exposure to light, heat, air and acidic environment.

Dry delivery forms are considered more difficult to stabilize.c. Tocopherols and tocotrienols are typically found in an oily medium in the presence of vegetable oils.

Such oily products are difficult to use except in the smallest of doses in dry delivery forms such as tablets without the use of specialized technologies to convert them to powders, granules or beadlets.d.

Conventional dry delivery conversion technologies do not provide good solutions for free flowing, directly compressible beadlets.

By nature, carotenoids are unstable at room temperature.

The beadlets obtained by the above known processes do not ensure stability to the active material either in the beadlet form itself, or when formulated into tablets.

In addition, none of the hitherto known methods of making beadlets provide desirable physical characteristics, such as spherical, free flowing beadlets suitable for tabletting or capsule filling.

Further, the beadlets produced by hitherto known methods do not prevent leaching of the active nutrients contained in such beadlets when subjected to compression to form tablets.

In recent times, use of excipients of animal origin in herb-based nutraceuticals is considered undesirable by a large section of users.

Due to poor digestibility, use of gelatin based formulations have a limitation for use among the geriatric population.

Sometimes, lactose is used as an excipient in the main beadlet matrix due to its compressible nature, but its dairy product (animal) origin makes it unacceptable to many, and is therefore considered to be undesirable.

Thus, the formulation of oral delivery systems for lipophilic nutrients, particularly carotenoids such as lutein, lycopene, beta carotene, present a challenge to the pharmaceutical and food industries, due to the oily nature and instability of the carotenoids / lipids.

By nature, carotenoids and lipophilic nutrients are unstable in presence of oxygen and light.

Such processes suffer from drawbacks such as use of high temperature (180.deg.

), which are not suitable for many heat sensitive products such as carotenoids.

Unfortunately, this method using organic solvent medium is not applicable directly for the formation of beadlets of lipophilic nutrients, such as carotenoids, in spite of the above said advantages, due to their oily / waxy nature.

Further these nutrients, when subjected to fluidization, form a cohesive mass, which adversely affects the fluidization.

Therefore a process employing fluid-bed system using a non-aqueous coating medium has hitherto not been considered possible or demonstrated, for the preparation of beadlets of lipophilic nutrients such as carotenoids.