The challenges for manufacturers lie in the multi-component formulation of these ingredients.
Botanical ingredients must undergo certain treatments such as extraction, distillation, purification, concentration or fermentation in order to extract maximum herbal efficacy.
Plant extracts can also contain a range of water-soluble and oil-soluble compounds providing an additional formulation challenge. These compounds may also have hygroscopic properties.
These all add to the products’ tendency to deterioration, resulting in a short shelf-life and loss of ingredient potency.
“The harvest and extraction of the botanicals preparations means the active components are exposed to oxidation, hydrolysis, microbial attack and other environmental degradation,” said Joris Geelen, partner at Food Compliance International.
During storage this can lead to loss of active component, production of metabolites with no activity and, in some extreme cases, production of toxic metabolites.
The minerals and inorganic compounds contained in minute traces could also affect the final formulation and the bioactive’s therapeutic properties.
Some herbals do contain a higher content of minerals or inorganic compounds. Herbs which fall into that category include alfalfa (Medicago sativa), oats (Avena sativa), fenugreek (Trigonellae foenugraeci semen) and cichorium/chicory root (Cichorii radix).
These botanicals were the focus of a Hungarian study that found these herbs to be a rich source of calcium, chromium, manganese and molybdenum, adding to the herb’s beneficial therapeutic effect.
In addition, fenugreek and chicory root along with dandelion root (Radix Taraxaci) exhibited a positive calcium to magnesium ratio (1-1.5) as well as other elements (manganese, iron, copper, zinc) which could play a beneficial role in the immune system health.
Dr Jérôme Le Bloch, Health Claim & Food Safety Department at Nutraveris said that the use of natural extracts as source of minerals and inorganic compounds made the manufacturing of food supplements more complex.
“Pure minerals are stable and without any impurities,” he explained. “Moreover, it’s easy to control the exact amounts of mineral with chemicals.
“For instance, magnesium oxide provides 60.3% of magnesium, whereas magnesium acetate provides 17.1% and magnesium chloride 12%.
Despite a harder use of natural extract as source of vitamin, mineral or other compounds, Dr Le Bloch highlighted this was something that was becoming more frequent on the market.
Consumers are sensitive to this natural aspect of product, he said citing French phytotherapy speciaists Arkopharma and their range of multivitamins that contained 9 vitamins and 5 minerals sourced entirely from plants.
The inconsistencies encountered during manufacturing and formulation brings into question the source of the botanical.
Many factors, like genetic differences, intra- and interspecific variations, soil conditions, climate, growth conditions of plant crops and conservation method influence the composition of plants and therefore their preparations.
“Standardisation, quality and process control are key to keep up the variability to a strict minimum in these natural products,” said Geelen. “This is important in order to set up reliable trials to test the physiological effects of the preparations in a consistent way.”
More purified is not a synonym of ‘safer’ Geelen stated. “The botanical matrix often contains protecting substances and this reduces possible toxicity of certain compounds naturally present.”
“To ensure quality of botanicals, parameters such as the harvesting and collection of plants using Good Agricultural and Collection Practice (GACP) should be followed,” according to Dr. Heike Stier, senior consultant at analyze & realize, a consultancy for natural health products.
Other parameters include tests for contaminants (pesticide, herbicide residues, heavy metals, microbiology contamination as well as an extraction methodology as a means of quality assurance.
Bedding in innovation
As is the nature of innovative products such as botanicals, its production is a learning process that requires refining and tweaking in order to improve its formulation.
Several progress highlighted by Dr LeBloch include encapsulation to ensure the stability of the natural compound.
“This method is really interesting. As well as improving stability extract, it could avoid side effects (seen in capsaicin) and a burning sensation in the mouth.”
“Encapsulation can be used for compounds with bad or strong taste (such as essential oils) or to enable two incompatible ingredients or compounds to be combined. It can also control the release of the active.”
The bioavailability too of a compound has been subject to fine-tuning with the development of liposome, phytosome and cyclodextrin complexes such as cyclic glucose polymers.
“Some of these formulations increase the bioavailability,” explained Geelen. “Therefore, the traditional dosage should be examined and possibly changed in view of safety and efficacy.”
The advent of nanotechnology has frequently been mentioned in the same vein with its strengths in enhancing stability, bioavailability and efficacy of a herbal product.
“Nanocoating of the active components of extracts is effective in protecting the active molecules from oxidation, hydrolysis etc,” said Dr Stier.
“The use of Supercritical Fluid Extraction (SFE) can be applied to obtain extracts in microparticles as dry powders in which stability and activity is enhanced in contrast to classic methods.”
A fine balancing act
The last word, of course is with the consumer. With the demand for all-natural products, without additives or similar on the increase, the use of chemicals is clearly negative for some.
For botanicals in particular, it is difficult to work without preservatives, especially for liquid doses.
"Manufacturers are trying to limit the use of additives with innovative preparations since consumers are more and more aware of these aspects,” said Geelen.
“It is also dependent on the specific consumer target group,” added Dr Stier. “Someone who is interested in products based on natural ingredients may be keener to have it ‘all natural’ than others who seek the proven but mild efficacy from a plant-derived medicine.”
“In most-plant derived products non-natural excipients used are not a hurdle for most consumers. At the end of the day, efficacy, convenience and the overall experience will be the most important decision basis for the educated consumer.”