Challenges with Dissolution Testing and Quality Assessment for Commercial Feverfew Products

The purpose of this study was to develop a suitable dissolution test for feverfew products and to investigate the parthenolide content, disintegration, and dissolution performance of several marketed feverfew products. Parthenolide content was determined by a validated HPLC method. Disintegration was tested according to the USP requirements for botanical dosage forms. A suitable dissolution test method was developed to study the dissolution performance of feverfew products. Parthenolide content varied from 0 to 0.23% among the feverfew products tested. The average disintegration times of these products were significantly different (p < 0.005) and varied from 5 to 11 min. All products containing measurable parthenolide exhibited more than 85% dissolution of parthenolide content in 1 h; however, these products exhibited substantially different dissolution profiles. In the first 10 min, one product released more than 80%, but dissolution from the two other products could not be detected at all during that time. Although not currently required by USP, dissolution testing of formulated products can be a useful tool to evaluate the quality of feverfew finished products. Patients should be cautious when changing from one brand to another because of such differences in actual parthenolide content and release performance. Manufacturers should commit to proper quality control procedures to ensure that label claims for content and dose are accurate and realistic. may also affect the efficacy of the product. So far, even for some of the most popular botanicals, little is known about their pharmacological or toxicological profiles. All of these limitations cause great difficulty in identifying the individual components that can represent the pharmacological activity and be used for the evaluation of release properties of botanical products. Different countries have different regulatory guidelines for dissolution testing of botanical products. Since 2000, the European Pharmacopoeia has introduced three classes of plant extracts based on knowledge of the composition of the herbal medicinal products and how well the relationship of composition to activity is known. These are “standardized” extracts, “quantified” extracts, and “other” extracts (3). Standardized extracts are herbal preparations whose active moiety has been definitely identified and adjusted to a given content; examples include Senna and Belladonna extracts. Quantified extracts refer to those products in which there is a defined, realistic range of constituent(s) that are accepted to contribute to activity; examples include Ginkgo and St. John’s wort extracts. Other extracts are products for which no individual active component has been identified, for example, Extr. Valerianae and Extr. Echinaceae. Generally, botanical products made from quantified extracts and other extracts need not undergo dissolution testing as long as they are formulated as immediate-release products. For diss-14-03-10.indd 14 8/29/2007 9:06:56 AM dx.doi.org/10.14227/DT140307P14