Quality Criteria and Standardization of Phytopharmaceuticals: Can Acceptable Drug Standards Be Achieved?
Phytopharmaceuticals are composed of many constituents and are therefore very capable of variation. The variability of the plant material is due to different growth, harvest, drying, and storage conditions. Therefore, cultivation of the plants under standardized conditions is desirable. The polarity of the solvent, the mode of extraction, and the instability of constituents may also influence the composition and quality of the extracts and must therefore be kept constant. The quality criteria for herbal drugs are based on a clear scientific definition of the raw material. Depending on the type of preparation, sensoric features, moisture, ash, physical constants, solvent residues, and adulterations have to be checked to prove identity and purity. Microbiological contamination and foreign materials, such as heavy metals, pesticide residues, aflatoxins, and radioactivity are further criteria to be tested.
To prove the constant composition of herbal preparations, adequate analytical methods have to be applied (eg, photometric analysis, thin layer chromatography [TLC], high performance liquid chromatography [HPLC], and gas chromatography [GC]). Depending upon whether the active principle of the plant is known or not, different concepts (“normalization” vs. “standardization”) have to be applied in order to establish relevant criteria for uniformity.
Key WordsPhytopharmaceuticals Quality Standardization
Unable to display preview. Download preview PDF.
- 1.Bauer R, Czygan F-C, Franz G, Ihrig M, Nahrstedt A, Sprecher E. Demands on the quality of rationally applicable phytopharmaceuticals (in German). Dtsch Apoth Ztg. 1993;133:4105–1108.Google Scholar
- 2.Bauer R, Czygan F-C, Franz G, Ihrig M, Nahrstedt A, Sprecher E. Pharmaceutical quality, standardization and normalization of phytopharmaceuticals (in German). Z Phytother. 1994;15:82–91.Google Scholar
- 4.WHO. Research guidelines for evaluating the safety and efficacy of herbal medicines. World Health Organization, Regional Office for the Western Pacific, Manila; 1993.Google Scholar
- 5.Gaedcke F. Phytopharmaceuticals—Definition and explanation of important terms used in the judgement of their manufacturing process and quality (in German). Dtsch Apoth Ztg. 1991;131:2551–2555.Google Scholar
- 6.Carle R, Fleischhauer I, Fehr D. Judgement of quality of chamomile oils (in German). Dtsch Apoth Ztg. 1987;127(47):2451–2457.Google Scholar
- 8.Bauer R, Mayrbäurl I, Stuppner H. Comparative studies on the polar constituents of chamomile preparations (in German). Sci Pharm. 1981;59:2.Google Scholar
- 9.Schmidt, PC. Standardization (in German). Dtsch Apoth Ztg. 1997;137(5):315–322.Google Scholar
- 12.Bauer R. Standardization of Echinacea purpurea expressed juice on cichoric acid and alkamides (in German). Z Phytother. 1997;18:270–276.Google Scholar
- 13.Uehleke B, Frank B, Reinhard E. Valuation and comparability of phytopharmaceuticals (in German). Dtsch Apoth Ztg. 1993;13:4105–4108.Google Scholar
- 14.Kooperation Phytopharmaka. Therapeutic equivalence (in German). Dtsch Apoth Ztg. 1995;135:321–322.Google Scholar
- 15.Gaedcke F. Pharmaceutical equivalence (in German). Z Phytother. 1996;17:221–234.Google Scholar
- 16.Meier B, Linnenbrink N. Status and comparability of herbal drugs (in German). Dtsch Apoth Ztg. 1996; 136:4205–4220.Google Scholar
- 17.Feiden K ed. Arzneimittelprüfrichtlinien. Stuttgart: Wissenschaftliche Verlagsgesellschaft; 1997.Google Scholar
- 18.Harnischfeger G, Flämig H, Halbach G, Kopanski L, Nufer H, Poppe G, Stumpf H. Suggestions for frame requirements for testing and standardization of herbal raw materials and extracts in the industrial field (in German). Pharm Ind. 1983;45:793–795.Google Scholar
- 19.Schilcher H. Rating of phytotherapy within alternative and school medicine (in German). Ärztezeitschrf Naturheilverf. 1996;37:23–34.Google Scholar
- 20.Harnischfeger G ed. Qualitätskontrolle von Phyto-pharmaka. Stuttgart, New York: Georg Thieme Verlag; 1985.Google Scholar
- 22.Meier B. Pharmaceutical plant extracts. Encyclopedia of Analytical Science. 1995;3882–3892.Google Scholar
- 23.Stumpf H, Spieß E, Habs M. Herbal drugs: Solvent residues (in German). Dtsch Apoth Ztg. 1992; 132(11):508–513.Google Scholar
- 24.Steinhoff B. Quality control of herbs and herbal preparations in consideration of new legal regulations (in German). Z Arznei- & Gewürzpfl. 1997; 2(1):10–14.Google Scholar
- 26.EEC Notes for Guidance “Quality of Herbal Remedies” CD 75/318 EEC and CD 91/507 EEC.Google Scholar
- 28.Schulz H-U, Schürer M, Krumbiegel G, Wächter W, Weyenmeyer R, Seidel G. Investigations on liberation and bioequivalence of Silymarin preparations (in German). Arzneim-Forsch/Drug Res. 1995; 45(1):61–64.Google Scholar