Abstract
Ndinteh, Derek T., Dr.
The renewed significant interest in medicinal plants which hold an extensive therapeutic history has resulted in the need for the assessment of their quality using modern and sophisticated methods of their processing and usage. Herbal preparations are commonly comprised of variable and complex components of different species or one and the same species, the composition and number of chemical compounds vary significantly. Quality assurance and control is of high priority to warrant the efficacy and consistency of herbal products.
There are many factors that affect the quality of herbal preparations; and various parameters should be met when assessing the quality of these products. Through the use of chromatographic techniques such gas chromatography (GC) and ultra violet (UV) spectrometry, one is able to obtain a characteristic fingerprint of a specific plant that represents the presence of a particular quality defining chemical constituents. This assists in determining whether the active ingredients are present in each product.
Samples of herbal capsules and tablets containing Withania somnifera as a single or polyherbal formulation from seven different companies, were sourced off the shelves from pharmacies. The purchased formulations active ingredients were emptied into vials and grouped according to the batches of the same supplier and labeled accordingly by the laboratory assistant to ensure blinding. Methanol, chloroform and hexane solvents were used as reagents to extract all active ingredients contained within the samples. For ultra violet analysis a double beam spectrophotometer was used for absorbance measurements. A gas chromatograph hyphenated to a mass spectrometer was also used for analysis of formulations containing Withania somnifera. The results were plotted on graphs. The consistency of the products and presence of active ingredients were identified, and the quality of each herbal formulation was deduced.
To determine the quality of the selected products, mass specification and colour analysis were compared and the following results were obtained. Masses of each supplier ranged between meeting the specifications limit for variance (group 1, 3, 5, 7 and 9) and some