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In vitro cytotoxicity tests: Following international norms such as ISO 10993-5:2009, in vitro
cytotoxicity studies are widely used in the toxicity evaluation of a wide range of medicines.
Test samples and cultivated mammalian cells are incubated together in these experiments,
and the reactions of the mammalian cells are assessed using appropriate biological parame-
ters. These assays may offer quick information on the safe use of phytopharmaceuticals in
clinical practice, but they are not complete safety evidence. Cell death, cell growth, cell pro-
liferation, and colony formation inhibition are essential factors to consider when evaluating
cytotoxic endpoints. Cytotoxicity can be measured by counting the number of cells, the
amount of protein, the release of specific enzymes, the release of vital dye, the reduction of
the vital dye, or any other measurable metric [26].
Ames test (Gene mutation test in bacteria): The most typically used microorganisms for
this test are Salmonella typhimurium (TA1537, TA1535, TA97, TA97a, TA98, TA100, TA 102
strains) and Escherichia coli (WP2 uvrA strain). This is a reverse mutation assay in which
mutant bacteria (histidine dependent) in the culture medium are exposed to chemicals having
mutagenic potential and then return to the wild-type strain (histidine independent). In the
presence and absence of a suitable metabolic activation system, bacteria should be exposed
to the test sample (i.e., S9 fraction of rat liver) [27].
Genotoxicity tests: Regulatory authorities require genotoxicity studies for any new drug
candidate. When a new drug candidate molecule or a substance/extract is mutagenic and
genotoxic, it is no longer considered a medicinal product, and other toxicity tests are ignored.
The OECD, ICH, and European Medicine Agency (EMEA) committees offer genotoxicity test
guidelines for drugs. Tests for the presence of DNA adducts and other primary DNA damage
(e.g., with strand break assays) in the target organs, or markers of genetic damage, such as
micronucleated erythrocytes in the test animals after the subchronic period, are examples
of toxicity testing. For risk assessment, molecular approaches to uncover pathways of geno-
toxicity in typical battery systems could be relevant. Transgenic animals and genomics tech-
nologies, among other recent methods, may be helpful in this area [28].
2.2.3 In vivo test for chromosomal damage using rodent hematopoietic cells
2.2.3.1 Mammalian bone marrow chromosome aberration test
This test is used to determine whether the test sample causes structural chromosomal ab-
errations in the bone marrow cells of rodents. Bone marrow is the target tissue in this test
because of its high vascularization and large population of quickly renewing cells. Animals
are given a particular route to be exposed to the test material before being sacrificed after
a set amount of time has passed. A metaphase-arresting drug (such as colchicine or Colce-
mid) is given to the animals before sacrifice. The bone marrow cells’ chromosome prepara-
tions are then stained, and metaphase cells are examined for chromosome aberrations [29].
2.2.3.1.1 Cytogenetic evaluation of chromosomal damage with mammalian cells
a) In vitro micronucleus test in mammalian cells: Micronuclei in the cytoplasm of inter-
phase cells are detected using an in vitro micronucleus assay in mammalian cells. This
test is approved for determining chromosome breakage or loss. This in vitro assay tech-
nique uses cultured mammalian cells from human peripheral blood lymphocytes or ro-
dent cells lines such as CHO, V79, CHL/IU, and L5178Y [30].
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b) In vitro mammalian cell gene mutation test: Mutant cells lacking Hprt enzyme activity
in the HPRT test or xprt enzyme activity in the XPRT test are resistant to the purine
analog 6-thioguanine’s cytostatic effects (TG). Hprt (in the HPRT test) or gpt (in the
XPRT test) proficient cells are sensitive to TG, which inhibits cellular metabolism and
causes cell division to cease. As a result, mutant cells can proliferate in the presence of
TG, whereas normal cells that contain the Hprt (in the HPRT test) or gpt (in the XPRT
test) enzyme cannot [31].
Reproductive and developmental toxicity tests: Potentially harmful effects of phytophar-
maceuticals on male and female reproductive function, embryo-fetal development, and pre-
natal and postnatal development should be investigated using internationally recognized test
procedures. These screening tests focus on male and female reproductive functions such as
gonadal, mating behavior, conception, conceptus development, and parturition. Screening
tests do not provide complete data on all aspects of reproduction and development [32].
Carcinogenicity tests: These are used to assess the tumorigenic potential of experimental
animals and extrapolate potential dangers to people. Carcinogenicity studies are advised if
there are any worries about the carcinogenic potential, such as the proximity of the test
extract or compound to those carcinogenic, or if suspicion develops from repeated dose
toxicity studies. Genotoxic substances, on the other hand, are thought to cause cancer. As
a result, if a genotoxic impact is determined during in vitro and in vivo experiments, it is
likely to be a carcinogen, and carcinogenicity tests are not required. Carcinogenicity tests
are not performed regularly [33].
Toxicokinetic studies: Pharmacokinetic and toxicokinetic data are crucial for establishing
a solid foundation for pharmacological efficacy and estimating potential toxicity concerns of
phytopharmaceuticals. Kinetic investigations include bioavailability studies to determine
how much and how quickly chemicals are absorbed following phytopharmaceutical
administration, clarification of putative metabolic pathways yielding potentially active novel
metabolites, and evaluation of elimination routes. These data are cru cial for determining
the phytopharmaceuticals’ pharmacological and toxicological effects. Despite the
availability of extensive pharmacokinetic and toxicokinetic information on active chemical-
pharmaceutical ingredients, phytopharmaceuticals and other herbal medications lack this
knowledge. These kinetic data are typically needed for an her bal ingredient with established
medicinal action or a defined constituent(s) with a predefined toxicological profile [34].
Additional toxicity tests: These studies are not necessary as part of standard toxicity
screening protocols, although they may be required based on the primary findings of the
toxicity studies outlined above or before clinical application. Furthermore, knowledge of the
biological effects of botanical species that are taxonomically linked to one other may reduce
the requirement for these tests. Additional investigations on immunotoxicity or neurotoxicity,
for example, maybe warranted if phytopharmaceuticals exhibit such biological actions. Organ
systems can be organized into a hierarchy based on their relevance in terms of life-sustaining
functions. In primary toxicity investigations, vital organs or systems such as the pulmonary,
cardiovascular, and central nervous systems are the most crucial to assess [16].
Immunotoxicity and antigenicity tests: Following standard toxicity studies and addi-
tional immunotoxicity tests, all novel pharmaceutical items for human use should be exa m-
ined for possible effects on immunological parameters (suppressive or stimulating).
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Immunotoxicity investigations may take precedence if there is any pharmacological data on
the usage of phytopharmaceuticals with antiinflammatory effects. Changes in serum globu-
lins, hematological changes such as leukopenia/lymphopenia, granulocytopenia/granulocy-
tosis, and lymphopenia/lymphocytosis, changes in organ weight and histology of immune
system organs (e.g., changes in the thymus, spleen, lymph nodes, and bone marrow), and
additional immunotoxicity tests may be needed based on reported traditional use [35].
Safety pharmacology studies: Preclinical safety pharmacology studies are currently being
used better to understand the impact of phytopharmaceuticals on essential organ func-
tioning. ICH recommendations recognize the safety pharmacology core battery test system
for medical goods. The effects of medical goods on the central neurological, cardiovascular,
and respiratory systems are determined using core battery tests. Phytopharmaceuticals are
covered under this guideline. This guideline determines follow-up studies for safety pharma-
cology core battery and extra safety pharmacology studies in addition to the core battery.
Other toxicity tests that can be performed under specified settings include immunotoxicity
and antigenicity, endocrine system toxicity testing, hepatic function tests as an indicator of
hepatotoxicity, and drug interaction investigations [36].
2.3 Issues involved in the delivery of natural products
In order to obtain uniform dosing, improved patient compatibility, stability, and optimal
therapeutic response, the herbal drug should be included in the appropriate formulation.
Since ancient times, the tradition of herbal medicinal formulation has been followed. Further-
more, a deeper understanding of multicomponent plant material and formulation methodol-
ogies and a wide range of standard and new formulation choices for the inclusion of
phytoconstituents were thoroughly investigated and established recently.
Herbal dosage forms refer to the physical form (liquid, solid, or semi-solid) of herbal med-
ications made from herbs in a specific formulation, with or without excipients (decoctions,
tablets, and ointments). Traditional formulations, conventional formulations, and unique for-
mulations are all options for preparing and delivering them. Plant-related issues, formulation
challenges, and regulatory challenges are all examples of challenges encountered while
formulating and delivering natural goods, as depicted in Fig. 9.2. Aside from better patient
compatibility, uniform dosing, and safe and convenient delivery, various formulation/
dosage forms are required to protect the herbal drug from the deteriorative effects of humid-
ity or atmospheric oxygen (e.g., coated tablets), to mask the bitter, salty, or offensive taste or
odor of a herbal drug (e.g., coated tablets, capsules, flavored syrups), to protect the herbal
drug from the deteriorative effects of humidity or atmospheric oxygen (e.g., coated multidrug
formulation), to improve the therapeutic efficacy of a poorly soluble or permeable herbal
drug by increasing their bioavailability (e.g., Novel drug delivery systems), to provide liquid
products of drug substances that are either unstable or instable at the administration site (e.g.,
various controlled-release nano formulations, capsules, tablets, and suspensions), to provide
liquid products of drug substances that are either unstable or instable at the administration
site (e.g., Novel drug delivery systems), to provide liquid products (e.g., transdermal patches,
creams, ointments, ophthalmic, ear, and nasal formulations), to provide for the insertion of
herbal drug substances into one of the body cavities for local effects (e.g., rectal or vaginal
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suppositories), to target a specific herbal drug to a specific site/organ of the body through
inhalation therapy (e.g., aerosols and inhalers), to provide for the insertion of herbal drug
substances into one of the body cavities for local effects (e.g., rectal or vaginal suppositories),
to (for example, targeted medicine delivery), and so forth [37].
• Medicinal plant-rel ated challenges: Authentication issues, complexity in phytochem-
istry, lack of scientific proof on safety, and standardized methodology, clinical trials of
poor quality and reporting of poor quality, good agriculture and collection procedures
(GACP) as well as good industrial techniques are lacking (GMP), adulteration or substi-
tution has resulted in a loss of quality. Variability in chemical ingredient type and pro-
portions; presence of pollutants, biopiracy, and Intellectual Property Rights (IPR); and
so on.
• Pharmaceutical challenges: Low aqueous solubility, lipid solubility, and bioavailability;
difficulty in formulation and development, difficulty conducting preformulation
research, difficulty determining the shelf life of a product, instability, pharmacokinetic
changes, and so on.
• Regulatory challenges: Regulatory variations, premarket and postmarket control regula-
tion variations, incorrect product categorization, and so on.
Pharmaceutical challenges usually begin with a preformulation study and end with a
dosage form review. The following are some examples of possible issues in this category.
• Preformulation study issues: The examination of physicochemical features of natural
products that can affect the performance and development of efficacious dosage forms
FIGURE 9.2 Some of the key aspects related to delivery of natural products.
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is the fo cus of a preformulation study. Stability analysis (solution stability, solid-state
stability, and drug excipient compatibility), solubility analysis (e.g., pKa determination,
pH solubility profile, partition coefficient, dissolution, etc.), bulk characterization, e.g.,
crystallinity and polymorphism, hygroscopicity, micromeritics properties are all part of
the preformulation study. Multicomponent herbal extract or enriched fractions are used
as API in herbal formulations. Preformulation studies on each component present in the
plant extract are challenging to do. On the other hand, the complete plant extract can be
chosen for preformulation research with as many parameters as possible evaluated [38].
• Poor aqueous or lipid solubility and bioavailability: Insufficient solubilization, dissolu-
tion, and inadequate absorption and bioavailability are caused by low aqueous solubil-
ity. Poor lipid solubility also reduces transmembrane permeability, resulting in
decreased absorption. Passive diffusion across the biomembrane, systemic absorption,
and eventually bioavailability are all hampered by the greater molecular size and
complicated structure. Phytoconstituents’ poor lipid solubility limits their penetration
through the lipid-rich biological membrane after oral or topical treatment, despite their
good in vitro bioactivity. For instance, Rutin is a common flavonoid found in most
plants, although it has low aqueo us solubility and bioavailability. Ant itumoral, antimi-
crobial, antioxidant, antiinflammatory, antibacterial, and antiviral effects of quercetin, a
flavonoid molecule, have been researched. Quercetin’s low water solubility and poor ab-
sorption prevent it from being widely used in medicine. Silymarin, a flavonolignan pro-
duced from the plant Silybum marianum, has a wide range of pharmacological effects
but has low oral bioavailability due to its low water solubility and poor membrane
permeability [39,40]. Using sound formulation strategies to load plant extract into novel
formulations, such as phytosome, solid dispersion, polymeric nanoparticles, nanoemul-
sions, liposome, solid lipid nanoparticles [41], can assist in tackling these issues.
• Instability: During storage or in the stomach environment during oral delivery, several
phytopharmaceuticals may become unstable. Hydrolysis, oxidation, crystallization,
enzymatic deterioration, emulsion disintegration, and interactions with excipients all
contribute to the denaturation of herbal products during storage. The two most critical
elements that affect the stability and quality of phytopharmaceuticals are temperature
and moisture. Chemical instability and lower therapeutic effectiveness result from the
gastrointestinal degradation of multiconstituent herbal products. For instance, when
quercetin is exposed to a severe acidic environment inside the stomach, it degrades to
phenolic acids such as protocatechuic acid via a ring fission process, resulting in a skel-
eton denaturation. As a result, considerable efforts should be made initially during raw
material storage and processing, among other things. Furthermore, choosing the suitable
formulation method can prevent these compounds from stomach denaturation [39].
• Formulation and development issues: Herbal extracts are typically hygroscopic,
viscous, and amorphous, with poor flowability and physicomechanical properties. It is
tough to handle and pound an exact extract because of its sticky and hygroscopic na-
ture. It is difficult to subject solid dosage forms to direct compression during formula-
tion and development, like tablets. However, introducing nonhygroscopic excipients
(e.g., dextran) before direct compression can circumvent the problems mentioned earlier.
It can be challenging to identify a common solvent for the solubilization of extract and
excipient during the formulation and development of herbal products. Some
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phytoconstituents are thermolabile, which can be destroyed when processed at a higher
temperature [10].
• Evaluation of formulation issues: It is challenging to characterize a formulation due to
the chemical complexity of the herbal extract. Due to a single active API, evaluating
drug concentration, homogeneity, dissolution, diffusion, and bioavailability in the
finished conventional allopathic dosage form is relatively simple. However, due to
various phytoconstituents in herbal products, evaluating the finished herbal products
concerning every component is exceptionally challenging. In this instance, it is good to
test the completed herbal product for known marker chemicals (active marker and
analytical markers). The drug content, for example, should be assessed by determining
the amount of active and analytical indicators. Furthermore, because herbal products
contain several elements, any single constituent’s concentration in the final formulation
is relatively low. Because the corresponding plasma concentration is low, in-vivo
bioavailability studies require complex analytical techniques [34].
• Altered pharmacokinetics: The presence of other phytoconstituents, also known as ef-
fectors in an her bal extract, may modify the bioavailability of constituents in that
extract. These effectors do not usually have pharmacological effects on their own, but
they can improve the solubility, resorption rate, half-life time, and stability of the ex-
tract’s principal active ingredients, resulting in increased bioavailability. The PK profile
of crucial active ingredients may be affected by variations in the chemical profile and
constituents within the extract. For instance, khellin, a vital component of the plant
Ammi visnaga, is entirely accessible after 10 min of extract ingestion , but not until 60 min
of plain equimolar khellin consumption. Saponins, for example, have no unique phar-
macological effects, although they do boost the bioavailability of the extract’s primary
components. Similarly, the greater bioavailability of vitamin-C from citrus fruit extract
compared to pure vitamin-C is due to improved ascorbic acid absorption and stability
in the presence of other flavonoids [42].
• Shelf-life Assessment issues: The shelf life of an API in a formulation is the period dur-
ing which it is expected to remain stable beyond the predetermined stability criteria,
provided that adequate storage conditions are maintained as directed on the product la-
bel. According to Ayurveda, a formulation is stable until it reaches the best before use
date, beyond which one or more of the formulation’s qualities are lost, affecting the
therapeutic effectiveness. The stability of active API in allopathic formulations is
currently assessed according to the International Council for Harmonization (ICH) and
World Health Organization (WHO) guidelines; however, the stability of herbal drugs is
currently assessed according to the Ayurveda, Yoga and Naturopathy, Unani, Siddha,
and Homeopathy (AYUSH) guidelines. The expiry date of Ayurvedic, Siddha, and
Unani (ASU) medicines should be indicated on the finished herbal product, according
to the Gazette notification (G.S.R. 789(E)) and regulation 161B issued by the Department
of AYUSH, Ministry of Health and Family Welfare, on August 12, 2016, as per the
Drugs and Cosmetics (5th Amendment) Rules. Stability indicating parameters such as
assay value of chemical markers (active and analytical), the appearance of new spots in
TLC identification or complete disappearance of existing spot, physicochemical parame-
ters (moisture content, ash value, particle size), physical attributes, and functionality
tests, such as color, phase separation, caking, hardness, and so on, are all evaluated.
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Stability data for four ingredients of phytopharmaceuticals should be generated. A
reasonable strategy is to analyze stability and shelf life based on markers. The marker
compounds in the majority of traditionally used plants, on the other hand, are un-
known. Although marker chemicals are occasionally identified, there is still a paucity of
data on the bioactive marker. In such circumstances, analytical markers can be used to
estimate shelf life. Again, each component in a multicomponent herbal mixture has a
distinct shelf life, making it impossible to forecast the shelf life of the final product and
propose appropriate storage conditions [43].
3. Role of novel delivery systems in overcoming some of these challenges
In recent years, novel formulations incorporated with herbal components, extracts, or
enriched fractions have been actively utilized. These new formulations tend to combine com-
pounds with disparate qualities, modify the properties of the loaded substances, and boost
their bioavailability and therapeutic action. Plant extracts and bioactive components have
been used to create a wide range of innovative formulations, including liposomes, solid
dispersion, transferosomes, phytosomes, ethosomes, microspheres, polymeric nanoparticles,
nanoemulsions, solid lipid nanoparticles (SLNs), nanocapsules, and more. These new herbal
formulations are said to have benefits such as improved solubility, absorption, bioavail-
ability, protection from gastric degradation, improved physical and chemical stability,
improved tissue distribution, reduced required dose, targeted delivery, reduced side effects,
control over the release of incorporated medicament, and enhancement of therapeutic activ-
ity. These formulations also have several drawbacks, such as difficulty scaling up processes,
high costs, and instability, to name a few. Novel drug delivery can mitigate the delivery chal-
lenges of delivery of natural products in the following ways.
• Targeted/Site-specific phytopharmaceuticals delivery: Attachment of ligands to novel formu-
lations is possible to target the formulation to a specific spot [44].
• To improve solubility, permeability, absorption, and bioavailability: Some phytoconstituents
have low water solubility, making them difficult to dissolve and absorb. Because most
bioactive components of plant extracts, such as flavonoids, tannins, and terpenoids, are
highly water soluble, they have a low oral absorption rate due to their inability to pass
the biological lipid barrier. Because most phytoconstituents have large molecular sizes
and low lipophilicity, their transmembrane penetration is a rate-limiting stage in sys-
temic absorption. Plant components have low oral bioavailability due to the causes
mentioned above. Herbal medicines have potent in vitro efficacy, but their low solubil-
ity, absorption, and bioavailability are not reproducible in vivo investigations [45].
• To control the release of phytopharmaceuticals: Novel formulations can release the inte-
grated phytoconstituents in a controlled or sustained way, extending the duration of ef-
fect, reducing administration frequency, and improving patient compliance.
• To develop a compatible formulation: Some key phytoconstituents are only utilized infre-
quently during formulation because they are incompatible with other excipients. As a
result, such elements can be coated or encapsulated in innovative formulations to make
them compatible with excipients.
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• To reduce therapeutic dose: Because bioavailability and site-specific drug delivery have
improved, a lower dose is required to provide the same therapeutic benefit. As a result,
when compared to unformulated extracts and conventional formulations, novel formula-
tions’ therapeutic dose is often minimal.
• To mask the disagreeable taste and odor: some of the phytopharmaceuticals are bitter and
unpleasant. Novel formulations can disguise the taste and odor of their ingredients.
• For increasing the intracellular uptake: Most nanoparticles are passively taken up by cancer
cells due to their improved permeability and retention properties (EPR effect). Leaky
vasculature and poor lymphatic drainage characterize malignant cells. Nanoparticles
from the blood can permeate via the leaky vasculature around the malignant cell. The
decreased lymphatic drainage prevents the penetrated nanoparticles from being cleared
and accumulating at the tumor site early. As a result, the EPR mechanism accounts for
the majority of nanoformulation intracellular uptake [46].
• To protect the phytoconstituents from degradation: When exposed to gastric media, several
herbal extract elements break down, losing their stability and therapeutic effectiveness.
• To target the loaded constituent to a particular site: To target the loaded components to a
specific place of the body, targeting ligands can be coupled to various nanoformulations
(e.g., solid lipid nanoparticles, liposomes, exosomes).
4. Storage and stability issues
Single or many phytoconstituents can be found in herbal medicinal preparations. Herbal
compositions with many constituents are generally favored. Internal (interaction with an
excipient, interaction among phytoconstituents) and external environmental factors influence
the st ability of herbal products (e.g., temperature, light, humidity, moisture, oxygen, micro-
bial contamination, trace metal contamination, leaching from the container, etc.). Loss of sta-
bility has a significant impact on the finished herbal product’s safety and efficacy. As a result,
phytopharmaceuticals need to undergo rigorous systemic stability testing, comparable to
synthetic pharmaceuticals in the current medical system, to establish and assure cons istent
therapeutic efficacy and safety over their planned shelf lives [47]. An herbal drug’s stability
study aims to offer data on how the quality of a herbal raw material or finished herbal prod-
uct changes over time under various environmental factors, estimate the shelf life, and pre-
scribe optimal storage conditions. Herbal products have the same shelf life determination
as chemically defined Active Pharmaceutical Ingredients (APIs), but they require a more
extensive analysis for stability testing and shelf life calculation. Compared to
multiconstituentebased finished herbal products, determining the stability of isolated
phytoconstituent-based herbal products is simple. During the stability testing of
multiconstituentebased herbal products, specific problems must be overcome [48].
Appropriate quality principles have been devised in light of the challenges of phytophar-
maceutical stability. A collection of test criteria, comprising qualitative and quantitative indi-
cators, has been acknowledged as part of a complete control strategy for herbal substances to
signal the phytopharmaceuticals quality. It is impossible to analyze every phytoconstituent
due to the complex nature of natural products and numerous phytoconstituents. As a result,
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the herbal product as a whole is frequently regard ed as an active ingredient. Chemical
markers (active marker/active principle, analytical markers) found inside the herbal raw ma-
terial can be used to assess product quality, stability, and shelf life. A chemical marker’s
amount can be utilized to determine the quality of an herbal product. Quantitative determi-
nation of marker(s) whose levels can be extrapolated to their intended therapeutic advan-
tages is a suitable stability studies procedure for phytopharmaceuticals. In other words,
active markers/principles should be used to assess stability. Because most herbal goods
are made up of herbal medications, knowing the active marker in an herbal product may
not be enough. In such instances, assigning a specific biological activity to a set of active
markers is frequently impossible. Chromatography allows researchers to track changes in a
complex mixture of physiologically active chemicals found in herbal materials during preser-
vation. The United States Food and Drug Administration (USFDA) has incorporated biolog-
ical assay as quality control parameters. As a result of these regulatory guidelines, it is critical
to evaluate phytopharmaceutical shelf life in terms of chemical stability and biological activ-
ity. If there is not enough information regarding the active marker, analytical markers could
test product stability. In terms of stability testing, chromatograph ic fingerprints and proper
assay techniques using marker chemicals form the foundation of this idea, which is outlined
in shelf life standards. Regardless of how good this strategy is, its implementation is
frequently connected with analytical issues and significant expenditures [49,50]. Some critical
issues related to storage and stability are discussed below.
4.1 Issues related to storage and stability
• Chemical complexity: Plant natural products are a blend of phytoconstituents that is
exceedingly complex and heterogeneous [47,48]. These range in polarity from nonpolar
to very polar, hydrophilic to hydrophobic, acidic to alkaline, and molecular weight from
very low to very high. It is sometimes impossible to establish the stability of any phyto-
constituent in multicomponent-based finished herbal products due to structural
complexity and the presence of numerous phytoconstituents. The construction of a spe-
cific chromatographic fingerprint, which is required by regulatory recommendations for
determining the shelf life of an herbal product, is hampered by this chemical diversity.
• Variability in biochemical composition: Environmental factors (air, humidity, rainfall),
cultivation procedures (seed selection, growth conditions, fertilizers, pesticides), contam-
inants (heavy metal, microbial contamination), and collection methods all influence the
quantity and nature of phytopharmaceuticals either directly or indirectly. It means that
a specific herbal medication obtained from various sources/locations is likely to have
varied biochemical makeup. As a result, herbal products made from an herbal raw ma-
terial obtained from various sources and manufactured by various manufacturers have
varying biochemical compositions. The concentration of markers in similar formulas
from various manufacturers can vary greatly. As a result, such items must be taken in
various quantities to elicit a specific pharmacological reaction, and their shelf lives will
vary depending on the initial content of the markers.
• Presence of contaminants: Microbe contamination is another quality trait that may
represent a health risk and cause denaturation of some phytoconstituents due to micro-
bial enzyme activity. As a result, it measures microbial load in phytopharmaceuticals.
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It should be part of the stability research protocol. Pesticide residues and heavy metal
contaminants are two more undesirable ingredients in herbal products that attract toxic
manifestations and react with markers, potentially altering the phytochemical composi-
tion of the phytopharmaceutical over time and complicating the stability testing
program.
• Lack of knowledge of markers (analytical and bioactive) and difficulty isolating
markers: It is feasible to evaluate stability using chemical markers; however, marker
molecules for some therapeutically utilized plants are still unknown. Even when marker
chemicals have been reported, there may still be a lack of understanding regarding the
bioactive marker. It may not always be possible to obtain conventional markers.
Isolating and purifying markers from a plant extract is difficult due to a trace amount
of them.
• Difficulty in the selection of marker(s): The API in a synthetic, medicinal formulations
are well characterized and serve as markers for drug product stability studies. During
stability testing, any change in the quantity of that marker is directly tied to a change in
its therapeutic efficacy. The active ingredients in herbal medicines and herbal products,
on the other hand, are complex combinations of elements. The elements responsible for
the therapeutic actions are almost often unknown. To induce pharmacological activities,
they either operate independently, synergistically, or antagonistically. In most situations,
their medicinal effect results from chemically different phytoconstituents acting in a syn-
ergistic or additive manner. As a result, any change in the content of a specific marker
or set of markers during the stability study of an herbal ingredient or product is un-
likely to result in a similar change in therapeutic efficacy. As a result, choosing phyto-
constituents as markers for predicting the shelf life of an herbal substance/product is
the most challenging task in a reasonable stability testing technique. When two or more
herbal raw materials are joined to make a polyherbal composition, the issue becomes
even more problematic.
• Difficulty in assessing shelf life: Each component of phytopharmaceuticals has a var-
ied shelf life, making it difficult to forecast their shelf life and advise appropriate storage
conditions. For instance, one of the research groups used triterpenes such
cimiracemoside-A, actein, and 27-deoxyactein as markers for stability tests on Actaea
racemosa, while the other used polyphenols and triterpenes like cimiracemoside F, 3-epi-
26-deoxyactein, acting as markers. Polyphenols are more unstable at higher tempera-
tures than triterpenes, according to these investigations. These findings imply that the
vulnerability of different manufacturers to chemical change throughout shelf life and
the use of markers for assessing the stability of phytopharmaceuticals are highly vari-
able. It means that the shelf lives attributed to a particular phytopharmaceutical are
likely to differ depending on the markers used. As a result, determining the shelf life of
phytopharmaceuticals is challenging. Again, choosing a phytoconstituent as a marker
for stability research monitoring is problematic.
• Difficulty in analysis and analytical method development: Because herbal medications
are complex, developing analytical methods for determining every marker chemical is
difficult. Furthermore, during the stability evaluation of phytopharmaceuticals, more
analytical hurdles must be overcome. In a synthetic, therapeutic medication product, a
formulation may contain only one or two medicines. It is simple to analyze and
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