Food Supplement Formulations. Peter Berry Ottaway

Transcription

1 Food Supplement Formulations Peter Berry Ottaway

2 Food Supplements Food supplements now exist in a large number of physical forms. Now many variants of both tablets and capsules each with a specific chemical composition. Tablets need a compressible carrier and compression aids. Soft-gel capsules have an oil-based fill and need to keep non-oil soluble substances in suspension (beeswax and silicon dioxide).

3 Tablets Family Tree Compressed Tablets (Granulation / Direct Compression) Coated Uncoated Swallowable Swallowable Chewable Effervescent Fast melt Sugar coated Film coated Enteric coated Sustained release

4 Capsules Family Tree Capsules Soft-gel Hard-gel (two piece) Non-gelatin Gelatin Gelatin Non-gelatin Oil only Oil and solids Oil only Oil and solids Starch Cellulose

5 Physical Forms of Supplements Tablets. Main criterion is a compressible base such as dicalcium phosphate, dextrose etc. Some major ingredients are processed with starch or cellulose to make compressible granulations. Flow agents and mould ejection aids such as silicon dioxide, talc and stearates are essential in most products. Most tablets are film (mainly cellulose ethers) or sugar coated. Vitamins and minerals may also be coated for stability.

6 Physical forms of Supplements Soft-Gel Capsules. Shells can be from various sources of gelatin or from starch or cellulose complexes. Main criterion is that the contents are oil based with no aqueous component. For non-oil soluble components a suspending matrix has to be formed. Some nutrients can be found on inner surface of shell. This does not affect nutritional properties but can affect analysis.

7 Physical Forms of Supplements Hard-Gel capsules. These are two-piece shells composed of either gelatin, starch or cellulose. The fill comprises the active substances on a (normally) carbohydrate carrier. Flow agents are common.

8 Physical Forms of Supplements Liquids Liquid supplements are normally water based (syrups), requiring chemical preservation. The selection of compatible ingredients is essential. For example, the presence of copper or iron results in the rapid loss of vitamin C. Powders One of the simplest forms of supplements but can have stability issues due to oxygen and moisture in intersticial spaces

9 Vitamins Vitamins are a heterogeneous collection of substances grouped together by an impure definition. 13 vitamins are officially recognised, but some have a number of chemical forms. Of the 13, four are oil soluble and 9 are water soluble.

10 Vitamins The chemical forms of a vitamin can significantly affect their biological activity as a vitamin: e.g. Tocopherol (vitamin E) D or DL, alcohol or ester Thiamin hydrochloride or mononitrate These differences can lead to errors in formulation and in calculations from assays.

11 Analysis of Vitamins The analysis of vitamins in food supplements has been a problem for decades. Some of the reasons are: Supplements tend to be multi-component. Some can contain over 40 ingredients and additives. The wide variability in the physical and chemical forms (e.g. tablets, capsules). The wide variability in carriers and product matrices. The need for stability overages. The individual chemistry of the vitamins.

12 Vitamin Overages Need to maintain label claim levels during declared shelf-life of the product. None of the vitamins are stable. None of the vitamins degrade at the same rate. Degradation is affected by a number of factors including the chemical composition of the product. Manufacturer adds overages of vitamins calculated to compensate for loss during shelf-life.

13 Effect of Storage on Vitamin C Content of Potatoes Source : Berry Ottaway, 1992

14 Comparison of patterns of vitamin loss in vitamin A and C (in accelerated storage conditions) Multivitamins film coated tablets in glass bottles, Vit. A 40 C/75% r.h. (HPLC method) Value % months 1 month 3 months 6 months

15 Vitamin Overages Overages are normally calculated and quoted as a percentage of the label claim. Vitamin C Label claim 60mg 20% overage 12mg Total input at production 72mg The assay of a vitamin in a product is unlikely to equate to the label claim. it should be greater than label claim.

16 GROUPS OF VITAMINS AND MINERALS ACCORDING TO OVERAGES Vitamin Group 1. not exceeding 25% Beta Carotene Vitamin E Niacin Biotin Vitamin B6 Vitamin B2 Vitamin K Vitamin C Group 2. not exceeding 40% Typical Overages % Folic acid Vitamin B12 Vitamin D Group 3. not exceeding 50% Vitamin B1 Pantothenic acid Vitamin A EHPM/ERNA/AESGP

17 Vitamin Overages The addition of overages means that in different batches of the same product formulation the levels of the vitamins will vary depending on the time after manufacture that the product is sampled. e.g: Vitamin C label claim Stability overage 20% 60mg 72mg (total) Initial assay 72.1mg 6 months 68.4mg 12 months 65.8mg 24 months (expiry) 61.2mg

18 Past Problems with Analysis Varying extraction methodologies. Lack of awareness of confounding ingredients / additives. Errors in calculations, particularly vitamin E. Nutrients on soft-gelatin shell walls

19 Comparison of Analytical Results Obtained from Different Laboratories for Vitamin levels in a Multi-vitamin and Multi-mineral Tablet Product Vitamin Input / Tablet Laboratory A - 1 Laboratory A - 2 Laboratory B Laboratory C Laboratory D Laboratory E Thiamin mg/tablet Riboflavin mg/tablet method method Niacin mg/tablet method method Pantothenic acid mg/tablet _ Vitamin B 6 mg/tablet Vitamin B 12 µg/tablet _ 1.4 _ Vitamin C mg/tablet Folic acid µg/tablet Vitamin A µgre/tablet Vitamin E mgte/tablet _

20 Tolerance Ranges Adopted in EU Member States To allow for the various variances Manufacturing variances Vitamin overages Analytical variances Member State authorities have adopted acceptable ranges for levels of nutrients in fortified foods. Similar ranges are not yet adopted for supplements in many member states. A pragmatic approach is needed in enforcement. The European Commission is intending to include such ranges in its revision of the Nutrition Labelling Directive 90/496/EEC.

21 Summary Vitamins The analysis of vitamins in supplements is not straightforward for a number of reasons. Vitamin stability is a significant problem in all foods. Overages are added to supplements and fortified foods to allow label claims to be met. Most products should assay above label claim. Over the years there have been a number of problems with the extraction of vitamins from supplements. Appropriate tolerances need to be applied by enforcement authorities.

22 Minerals The minerals/trace elements can only be added in the chemical forms permitted in the law. There is some confusion amongst regulators and formulators on the factors used to derive the elemental content of the nutrient from the salt or ester. The chemical structure of the mineral source determines the amount of the source that needs to be added to make a label claim.

23 Minerals The RDA for calcium for labelling purposes is 800mg/day. The permitted Ca salt with the highest Ca content is the carbonate (CaCO 3 ) at 40.1%. Allowing for moisture and assay variations the level for formulation becomes 38.65%. Thus to meet the RDA the amount of CaCO 3 required becomes 2070mg (2.07g). This is too large for a single tablet or capsule so most units can only contain a proportion of the RDA.

24 Minerals Calcium gluconate, another permitted source, only contains 8.81% calcium. Thus, to meet the RDA in one unit 9080mg (9.08g) would be required.

25 Other Substances There is often confusion over the labelling and claims for other active substances found in supplements. A currently popular supplement is glucosamine. For stability purposes this has to be supplied as a protected salt as glucosamine sulphate.2kcl. Labelling can be: Glucosamine sulphate.2kcl (Approx 95% input) Glucosamine sulphate (Approx 75% input) Glucosamine (Approx 59% input)

26 Summary Food supplements come in a number of diverse forms with totally different matrices. Vitamins are inherently unstable and overages are normally needed to achieve realistic commercial shelf-lives. The addition of minerals/trace elements is often dictated by the chemical composition of the source. Care has to be taken with the numerical claims for many of the active substances.

27 Contact Details Peter Berry Ottaway 1A Fields Yard Plough Lane Hereford HR4 0EL United Kingdom Tel: Fax: Web: