Regulation and standardization of herbal drugs: Current status, limitation, challenge's and future prospective.

Herbal drugs (HD) or traditional drugs have been used worldwide for centuries, especially in the developing countries. Global market of HD reaches billion of USD annually and increases every year. For ensuring the safety and efficacy of HD, the Drug Agency/Authority issues regulations for the registration & application of new HD, their manufacturing processes, controlling and monitoring in the market. The efficacy and safety of HD depend on their whole chemical contents. Quality assessment of HD should be performed using standardization methods according to the current Pharmacopoeias or Materia Medica. Unfortunately, the official methods of the compendia cannot be applied for evaluation of mixed herbs and their preparations.; HD's producers should develop, validate, and standardize the method for the quality assessment of their own specific products. Therefore, assuring the safety and efficacy of HD remains a challenging task due to the complex nature of HD, that typically consist of many constituents of herbs/extracts whose quality may vary among different sources of materials. This present review will describe, compare, and discuss the regulations and standardization methods of HD from US, EU countries, Japan, Taiwan, Hong Kong and Indonesia. The official standardization methods of HD, their current criteria, limitations, challenge and future prospective will be described and discussed. Official methods for quality assessment of HD should be state of the art, fast, low-cost, accurate and precise, and could be used for evaluation of all kinds of HD.

Application of Chromatographic and Spectroscopic-Based Methods for Analysis of Omega-3 (ω-3 FAs) and Omega-6 (ω-6 FAs) Fatty Acids in Marine Natural Products.

Omega-3 fatty acids v(ω-3 FAs) such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) and omega-6 fatty acids (ω-6 FAs) such as linoleic acid and arachidonic acid are important fatty acids responsible for positive effects on human health. The main sources of ω-3 FAs and ω-6 FAs are marine-based products, especially fish oils. Some food, supplements, and pharmaceutical products would include fish oils as a source of ω-3 FAs and ω-6 FAs; therefore, the quality assurance of these products is highly required. Some analytical methods mainly based on spectroscopic and chromatographic techniques have been reported. Molecular spectroscopy such as Infrared and Raman parallel to chemometrics has been successfully applied for quantitative analysis of individual and total ω-3 FAs and ω-6 FAs. This spectroscopic technique is typically applied as the alternative method to official methods applying chromatographic methods. Due to the capability to provide the separation of ω-3 FAs and ω-6 FAs from other components in the products, gas and liquid chromatography along with sophisticated detectors such as mass spectrometers are ideal analytical methods offering sensitive and specific results that are suitable for routine quality control.

Partial Least Squares-Discriminant Analysis Classification for Patchouli Oil Adulteration Detection by Fourier Transform Infrared Spectroscopy in Combination with Chemometrics.

This study aims to test chemometrically partial least squares-discriminant analysis (PLS-DA) classification models to detect the adulteration of patchouli oil (PO) with gurjun balsam oil (GBO) by utilization of Fourier transform infrared spectroscopy. Unsupervised analysis was tested using the pattern recognition method using the principal component analysis model against the original spectrum at wavenumbers 4000-500 cm-1 and at the fingerprint area (1800-600 cm-1). Model testing was also carried out on the spectrum that had been pre-processed using the standard normal variate, second derivative Savitzky-Golay, and normalization approaches. Variable Y samples used were certified reference material (CRM), PO, GBO, and PO forged with GBO (PGBO) with a counterfeiting ratio of 0.5 (v/v) to 10% (v/v) with an interval of 0.5%. The same treatment was carried out on testing of the PLS-DA model. In pattern recognition tests, the best separation of the original spectrum was obtained at wavenumbers 1800-600 cm-1. The model was further tested on PLS-DA by making assumptions or codes for CRM, PO, GBO, and PGBO as +2, +1, 0, and -1, respectively. The results of the model analysis showed that even at the lowest counterfeiting ratio (0.5%), the presence of counterfeiting material was detected by the PLS-DA model. The RMSEC value is close to zero with a value of 0.22, and the R square is close to 1, which is 0.954. This very significant separation is clearly illustrated in the loading plot and bi-plot due to the contribution of chemical compounds in the GBO that undergo vibration at wavenumbers 603, 786, and 1386 cm-1. Validation of the PLS-DA model was carried out strongly using the PLS model, and it showed that the difference between the calibration concentration and the prediction was very low (average 0.45) with an accuracy percent above 99%. The efficacy of the model is further substantiated by the consistent and precise values of sensitivity and selectivity, obtained from both the training set and test set.

Advances in Fingerprint Analysis for Standardization and Quality Control of Herbal Medicines.

Herbal drugs or herbal medicines (HMs) have a long-standing history as natural remedies for preventing and curing diseases. HMs have garnered greater interest during the past decades due to their broad, synergistic actions on the physiological systems and relatively lower incidence of adverse events, compared to synthetic drugs. However, assuring reproducible quality, efficacy, and safety from herbal drugs remains a challenging task. HMs typically consist of many constituents whose presence and quantity may vary among different sources of materials. Fingerprint analysis has emerged as a very useful technique to assess the quality of herbal drug materials and formulations for establishing standardized herbal products. Rather than using a single or two marker(s), fingerprinting techniques take great consideration of the complexity of herbal drugs by evaluating the whole chemical profile and extracting a common pattern to be set as a criterion for assessing the individual material or formulation. In this review, we described and assessed various fingerprinting techniques reported to date, which are applicable to the standardization and quality control of HMs. We also evaluated the application of multivariate data analysis or chemometrics in assisting the analysis of the complex datasets from the determination of HMs. To ensure that these methods yield reliable results, we reviewed the validation status of the methods and provided perspectives on those. Finally, we concluded by highlighting major accomplishments and presenting a gap analysis between the existing techniques and what is needed to continue moving forward.

Application of chemometrics using direct spectroscopic methods as a QC tool in pharmaceutical industry and their validation.

This present review described the application of chemometrics using direct spectroscopic methods at the quality control (QC) laboratory of Pharmaceutical Industries. Using chemometrics methods, all QC assessments during the fabrication processes of the drug preparations can be well performed. Chemometrics methods have some advantages compared to the conventional methods, i.e., non-destructive, can be performed directly to intake samples without any extractions, unnecessary performing stability studies, and cost-effective. To achieve reliable results of analyses, all methods must be validated first prior to routine applications. According to the current Pharmacopeia, the validation parameters are specificity/selectivity, accuracy, repeatability, intermediate precision, range, detection limit, quantification limit and robustness. These validation data must meet the acceptance criteria, that have been described by the analytical target profile (ATP) of the drug preparations.

The importance of method validation in herbal drug research.

There are countless scientific publications on herbal drugs, but unfortunately many of them do not correctly report their chemical, biological and pharmacological aspects, including the composition and stability of the herbal/extract preparations, therefore their safety, efficacy and consistency could not be proven. For developing a modern drug from herbal drug(s), complete chemical and pharmacological characterizations of their bioactive metabolites need to be well established. Reproducible results require the development, assessment, and standardization of the chemical, biological and pharmacological methods based on the current state of the art. Therefore, all methods used in research must be properly validated before its routine applications. This present review will describe and discuss the important aspects of method validation (chemical, biological and pharmacological) in herbal drug research according to the newest current Pharmacopeia, official Guidelines and related recent publications.

Validation of in-vitro bioassay methods: Application in herbal drug research.

This present review described the validation method of in-vitro bioassay for its application in herbal drug research. Seven sequencing steps that can be taken for performing a valid bioassay include: literature survey, sample stability evaluation, Biosystem performance testing, Sample performance evaluation, determination of 50% effective concentration or cytotoxic concentrations, selective index evaluation, and determination of accurate relative potency of sample. Detailed methods and acceptance criteria for each step are described herein. Method calculations of the relative potency of sample using European Pharmacopeia 10.0, 5.3 (2020) were recommended instead of using United States Pharmacopeia 42 (2019). For having reliable data and conclusions, all methods (chemical and bioassay) need to be first validated before any data collection. Absence of any validation method may results in incorrect conclusions and bias.

Validation of Chromatographic Methods of Analysis: Application for Drugs That Derived From Herbs.

It is well known that the quality control (QC) of drugs derived from herbs (DDHs) has two main problems: first, DDHs are chemically complex mixtures, and second, the chemical contents of raw plant materials are affected by the site of cultivation, age of plants, methods of harvesting, and processing. QC is used by manufacturers to ensure the consistency, safety, and efficacy of the DDHs. QC of DDHs can be performed by two approaches, namely, marker-oriented and chemical pattern-oriented (metabolite profiling) using chromatographic methods. For having reliable results of any chemical analysis that will be performed in the QC laboratory, the method of analysis must be validated first before it can be routinely applied. Parameters of the validation method that should be evaluated for marker-oriented approach are stability, selectivity, linearity, trueness, precision, and robustness/ruggedness, while for metabolite profiling approach stability, intra- and interday precisions should be determined. Determination of instrumental and sample detection limit (DL), quantification limit (QL), and cutoff value is described in this review. Some relatively new validation methods that could correlate trueness and precision will be also discussed. The importance and application of metabolite profiling for a QC laboratory at pharmaceutical industry are discussed.

Metabolite Profiles in Various Plant Organs of Justicia gendarussa Burm.f. and Its in Vitro Cultures.

Metabolite profiles of plant organs and their in vitro cultures of Justicia gendarussa have been studied by using Ultra Performance Liquid Chromatography-Quadrupole Time-of-Flight-Mass Spectrometry (UPLC-Qtof-MS). Samples of leaves, stems, roots, and shoot cultures showed similar patterns of metabolites, while samples of root cultures gave very different profiles. Concentrations of secondary metabolites in shoot cultures were relatively low compared to those in the leaves and roots of the plants. The results suggested that secondary metabolites in J. gendarussa were biosynthetized in the leaves, then transported to the roots.

Valsartan.

Valsartan is an antihypertensive drug which selectively inhibits angiotensin receptor type II. Generally, valsartan is available as film-coated tablets. This review summarizes thermal analysis, spectroscopy characteristics (UV, IR, MS, and NMR), polymorphism forms, impurities, and related compounds of valsartan. The methods of analysis of valsartan in pharmaceutical dosage forms and in biological fluids using spectrophotometer, CE, TLC, and HPLC methods are discussed in details. Both official and nonofficial methods are described. It is recommended to use LC-MS method for analyzing valsartan in complex matrices such as biological fluids and herbal preparations; in this case, MRM is preferred than SIM method.

Metabolite Profiling of Justicia gendarussa Burm. f. Leaves Using UPLC-UHR-QTOF-MS.

An ultra-performance liquid chromatography ultra-high-resolution quadrupole-time-of-flight-mass spectrometry (UPLC-UHR-QTOF-MS) metabolite profiling ofxs Justicia gendarussa Burm. f. leaves was performed. PCA and HCA analyses were applied to observe the clustering patterns and inter-sample relationships. It seemed that the concentrations of Ca, P, and Cu in the soil could affect the metabolite profiles of Justicia gendarussa. Six significant metabolites were proposed.

Curcumin.

Curcumin and its two related compounds, that is, demethoxycurcumin and bis-demethoxycurcumin (curcuminoids) are the main secondary metabolites of Curcuma longa and other Curcuma spp. Curcumin is commonly used as coloring agent as well as food additive; curcumin has also shown some therapeutic activities. This review summarizes stability of curcumin in solutions, spectroscopy characteristics of curcumin (UV, IR, Raman, MS, and NMR), polymorphism forms, method of analysis in both of biological and nonbiological samples, and metabolite studies of curcumin. For analysis of curcumin and its related compounds in complex matrices, application of LC-MS/MS is recommended.

Aripiprazole.

Aripiprazole is an atypical antipsychotic drug which belongs to the benzisoxazole derivatives. Aripiprazole is available in many salts and polymorphs forms. X-ray diffraction, IR spectroscopy, and DSC could be used for differentiating the polymorphs of aripiprazole. Some instrumental methods of analysis such as UV spectrophotometer, HPTLC, HPLC, and CE can be applied for analyzing aripiprazole and its impurities. Chromatography methods that have an MS/MS detector is the method of choice for analyzing aripiprazole and its metabolites. Bioavailability studies of the polymorphs of aripiprazole and their pharmaceutical preparations are very important to optimize the formulations of the dosage forms.

Lecythomycin, a new macrolactone glycoside from the endophytic fungus Lecythophora sp.

A new macrolactone glycoside, lecythomycin (1), 23-methyl-3-(1-O-mannosyl)-oxacyclotetracosan-1-one, was isolated from the endophytic fungus Lecythophora sp. (code 30.1), an endopyte of the Indonesian plant Alyxia reinwardtii. The structure of 1 was elucidated on the basis of NMR spectroscopic and mass spectrometric data. The isolated compound displayed antifungal activity against strains of Aspergillus fumigatus and Candida kruzei at minimal inhibitory concentrations (MIC) of 62.5-125 microg/mL.

Ezetimibe.

Ezetimibe is a drug substance which can be used for lowering low-density lipoprotein cholesterol. Its crystal form and polymorphism have been determined using X-ray diffraction and thermal methods. Quantitative and qualitative analysis of Ezetimibe as well as study of its impurities and degradations were summarized in this chapter.

Glimepiride.

Glimepiride, which belongs to the sulfonylurea group, has been widely analyzed for its physical chemical properties including its crystallinity. Moreover, methods to quantify glimepiride and its impurities, either in pharmaceutical dosage form or in biological sample, have also been extensively developed and reported. This chapter extracts all information needed to give more perspective regarding to this substance.