Thai Herbal Product Stability Testing Service (Herbal Product Stability Hub): Covering 14 Herbal Product Dosage Forms

Thailand’s herbal product industry is growing steadily, both in the domestic market where consumers are turning to traditional health practices, and in export markets where importers in ASEAN, Japan, the European Union, and the United States place increasing value on natural products backed by scientific evidence. The shared requirement of both markets is proof of shelf life and stability of active compounds.

The challenge of Thai herbal products lies in their chemical complexity. Unlike modern pharmaceuticals based on a single purified substance, herbal products contain multiple compounds that vary with growing region, harvest season, extraction method, and packaging system. Conducting stability testing that meets international standards and the Thai Herbal Pharmacopoeia (THP 2021) is therefore a critical tool for building the scientific documentation needed to register with the Thai Food and Drug Administration (Thai FDA) and to negotiate with international importers.

TIBD’s service is designed specifically for Thai herbal products, covering stability testing protocols per ICH Q1A(R2), ASEAN Zone IVb conditions, and THP 2021 criteria, including Marker Compound analysis and Phytochemical Fingerprinting (TLC/HPTLC Fingerprinting), in partnership with VISBIO as an Independent Quality Assurance Verifier (IQAV) using Validated Methods per ICH Q2(R1). This page is the Hub guiding you to stability testing services for the 14 herbal product dosage forms that TIBD supports.

A herbal product under the Herbal Product Act B.E. 2562 (2019) refers to a product whose primary components come from plants, animals, microorganisms, or minerals, used for the purposes of health care, treatment, relief, prevention, or cure of disease. This covers traditional Thai medicine, alternative medicine, single herbs and herbal formulas, and herbal health products.

Thai herbs commonly used in commercial products include Turmeric (Curcuma longa) with Curcuminoids as the Marker Compound; Andrographis (Andrographis paniculata) with Andrographolide; Fingerroot (Kaempferia parviflora) with Methoxyflavones; Centella (Centella asiatica) with Asiaticoside; Moringa (Moringa oleifera) with Glucosinolates; and Amla (Phyllanthus emblica) with Tannins.

The Thai herbal product market has a structure that manufacturers must always consider. In the domestic market, consumers require products registered with the Thai FDA, with a clearly stated shelf life and scientific evidence. In export markets, foreign importers require product qualification documentation referenced to ASEAN and ICH standards, with Marker Compound data analyzed by High Performance Liquid Chromatography (HPLC) or an equivalent technique.

TIBD provides stability testing for herbal products covering 14 dosage forms. Each dosage form has specific protocols and testing parameters designed to address the physical, chemical, and microbiological characteristics of that form.

The solid oral dosage group covers Plain Herbal Tablets, Film-Coated Herbal Tablets, Chewable Herbal Tablets, Effervescent Herbal Tablets, Herbal Pills (Luk Glaun), Herbal Licap/Soft Capsules, Hard Capsules and Herbal Granules, Herbal Softgel and Lozenges, Herbal Sachets, and Herbal Powder.

The liquid dosage group covers Herbal Syrup, Herbal Oral Liquid, Herbal Ready-to-Drink Beverages (Herbal RTD), Herbal Gummy, Herbal Jelly, and Herbal Tea.

The topical dosage group covers Herbal Balm, Herbal Gel, Herbal Cream, Herbal Spray, Herbal Medicated Oil, and Herbal Inhaler.

Users interested in the details of each dosage form can access dedicated articles covering specific testing parameters, THP 2021 acceptance criteria, and packaging considerations for that form. Each dedicated article provides deeper technical detail and the specific challenges of that dosage form.

The key difference between stability testing for herbal products and modern pharmaceutical products is that herbs have complex chemical compositions. Measuring only a single Marker Compound may not be sufficient to demonstrate the overall stability of the product. Two techniques must therefore be used together.

Marker Compound analysis uses High Performance Liquid Chromatography (HPLC) or Ultra Performance Liquid Chromatography (UPLC) for non-volatile compounds, and Gas Chromatography-Mass Spectrometry (GC-MS) for volatile compounds in herbal oils. Examples of Marker selection: Turmeric uses Curcuminoids (Curcumin, Demethoxycurcumin, Bisdemethoxycurcumin); Andrographis uses Andrographolide; Fingerroot uses Methoxyflavones (5,7-Dimethoxyflavone).

Phytochemical Fingerprinting (TLC/HPTLC Fingerprinting) is a technique that captures the overall profile of multiple compound groups simultaneously, providing a Similarity Index for comparing between lots and between pull points in the stability study. A Similarity Index above 0.95 indicates that the chemical profile of the product remains close to the initial state.

Using both techniques together provides a complete picture. Marker Compound analysis answers whether the primary active compounds are still present in sufficient quantity, while TLC Fingerprinting answers whether the overall chemical profile remains consistent with the manufactured and registered form.

Thailand and the ASEAN region fall within ASEAN Zone IVb, a hot and humid climate zone. Testing conditions per international standards must therefore reflect the real environment of the target market.

Long-term Stability testing uses 30°C / 75% RH conditions for a minimum of 12 months, and may be extended to 24 to 36 months for products requiring full shelf-life determination. Accelerated Stability testing uses 40°C / 75% RH conditions for 6 months to support preliminary registration and shelf-life prediction. Intermediate Stability testing uses 30°C / 65% RH conditions for 12 months when accelerated testing results show significant change.

Standard pull points for long-term testing are at months 0, 3, 6, 9, 12, 18, 24, and 36. For accelerated testing, pull points are at months 0, 1, 2, 3, and 6. For herbal products containing volatile compounds, such as balms, herbal oils, and inhalers, TIBD adds monthly pull points in the first 6 months to capture volatile compound changes in detail.

The Thai Herbal Pharmacopoeia (THP 2021) specifies acceptance criteria for herbal products, used in conjunction with ICH Q1A(R2) standards.

For Marker Compound content, the value at the initial time point must be within the range specified in the product specification document (generally 90 to 110% of the stated quantity), and must not fall below 90% of the initial value throughout shelf life. For Fingerprinting, the Similarity Index between T0 and Tx must not fall below 0.95.

For dosage-form-specific criteria: Pills and dry products must have a Water Activity (aw) value not exceeding 0.60 to inhibit microbial growth. Balms and herbal oils must retain volatile compounds at not less than 85 to 90% and pass Odor Persistence testing. Herbal RTD beverages and syrups must pass Microbial Limit Testing at every pull point.

For contamination testing, the Thai Herbal Pharmacopoeia requires herbal products to pass Heavy Metal testing, Pesticide Residue testing, and Aflatoxin testing at the initial pull point. Although these parameters do not change over time, they are required documentation for registration.

The Herbal Product Act B.E. 2562 (2019) requires herbal products registered with the Thai Food and Drug Administration (Thai FDA) to have stability data from testing per ICH Q1A(R2) or an equivalent standard, and to state a shelf life on the label based on scientific data rather than estimation from other products.

The ASEAN Guideline on Stability Study of Drug Products (2013) additionally requires that testing conditions be appropriate for Zone IVb for products sold in ASEAN, that sampling frequency be consistent with ICH Q1A(R2), and that data presented cover at least 3 production lots.

For products registered under Traditional Thai Medicine per Ministry of Public Health notifications, the stability documentation requirements may differ in some details from those for herbal health products. TIBD designs protocols that meet the requirements of both categories according to the specific request of each client.

Exporting Thai herbal products to foreign markets involves opportunities and challenges in the dimension of quality documentation. Importers in ASEAN markets including Singapore, Malaysia, Vietnam, Indonesia, and the Philippines require stability data referenced to ICH Q1A(R2) and the ASEAN Stability Guideline, together with a Certificate of Analysis (COA) showing Marker Compound data and microbiological test results.

In Japan and European Union markets, importers place importance on TLC/HPTLC Fingerprinting and data covering 3-lot studies at 24 months long-term. For the United States market under DSHEA (Dietary Supplement Health and Education Act), herbal products classified as Dietary Supplements must have current Good Manufacturing Practice (cGMP) documentation and stability data to support the Best Before Date.

The advantage of manufacturers who test under ASEAN Zone IVb conditions is that this data covers a more demanding environment than many target markets, making products tested in Thailand highly credible in markets with a milder climate.

The credibility of a herbal product stability testing report depends on the independence of the analyst. VISBIO, acting as an Independent Quality Assurance Verifier (IQAV), performs Marker Compound analysis, TLC/HPTLC Fingerprinting, and microbiological testing on samples collected at TIBD’s pull points, using Validated Methods per ICH Q2(R1) with full traceability documentation at every step and operations conducted under ISO/IEC 17025 standards.

For Thai herbal products with high chemical complexity, having an independent third-party IQAV gives importers and regulatory authorities in ASEAN, Japan, and Europe confidence in the data presented, reducing questions and additional requirements during the registration process.

The Thai herbal product stability testing service is conducted in partnership with Dr. Wuttipong Panitsettakorn, Advisor and Co-Founder, who specializes in commercial technology management for the health and beauty industry, and Ms. Mandhamon Uttamo, Advanced Formulator, with experience in formula development and packaging system selection for Thai herbal products. Our team includes researchers specializing in Phytochemistry, Pharmacognosy, and Botanical Standardization, and a network of researchers covering Marker Compound analysis, HPTLC Fingerprinting, and microbiological assessment of herbal products.

Is your Thai herbal product ready for Thai FDA registration or for export? If you need stability data referenced to ICH Q1A(R2), the ASEAN Stability Guideline, and the Thai Herbal Pharmacopoeia (THP 2021) for a herbal product in any dosage form, contact TIBD for a customized protocol designed for your product. Related articles for each dosage form are available in the TIBD Thai Herbal Product Stability Testing Hub.