All substances are poisons; there is none which is not a poison. The right dose differentiates a poison - Paracelsus

 Anciently toxicology was known as ‘Science of Poison,’ now a days it is defined as, the study of the effect of chemicals on living organisms and their evaluation as whether these entities are harmful or not or estimating a safe range. For the establishment of safety margins from the adverse effects of chemicals, toxicology depends on few factors like dosage, route of exposure and duration of a certain chemical. The safety level of chemical is decided by the execution of sets of step wise experiments. 

Toxicology plays major part in drug development to decide the safe dose and drug response on an exposed organism which includes four disciplines like biology, chemistry, pharmacology and lastly medicine with an intervention of information technology up to some extent. In the current scenario toxicology studies are of great importance in the field of Pharmaceuticals, Agrochemicals and Ayurvedic Products.

Pharmaceutical Toxicology: Main concern in pharmaceutical industries is the side effects of their drug or medicine which is one of the biggest reasons of failure in drug development. Toxicologists carry safety studies in accordance with the regulatory guidelines to show regulators that a certain drug is safe to use for its intended indication. Pharma industry mostly depends on their synthetic chemistry arm for drug development which initially undergoes efficacy studies before entering safety screening

phase of their molecule or biomolecule as called early drug development.

• Synthetic chemist designs molecule with the help of computer modelling tools with the inputs of pharmacophores for the intended target.

• In early screenings these molecules screened through knowledge-based computer models to predict the toxicity (toxophores) in these complex molecular structures.

• In next step the toxicologist conducts in vitro assays to rule out the possible specific toxicities.
• Toxicity of the molecule within the body can impact through metabolism also studied by few in vivo assays and can later help during drug candidate selection.
• Candidate drug thoroughly are assessed for toxicity which usually consist of animal studies. The studies include deep examination of organs, tissues, blood and urine collected from the exposed animals.
• For specific type of toxicities specially designed toxicity studies required such as cancer and reproduction toxicity studies. Further investigation by sophisticated studies are performed with more parameters required to establish safety of the candidate drug.
• Pharma companies demonstrate safety of the drug through toxicity studies data to regulatory authorities for approval of their drug/chemical entity to be used in humans.

Agrochemicals: As the name suggests chemicals used in agriculture which commonly includes pesticides (insecticides, herbicides, fungicides, nematicides), synthetic fertilizers, natural (manure), hormones, growth enhancers. Over a period, when used for a long time these agrochemicals become pollutants to our ecosystem. Establishment of their safety and risk assessment is equally important as any pharmaceutical drug. In case of agrochemicals, it is called as ecological risk assessment (ERA) works first for the protection of ecosystem and second registration of agrochemicals or regulatory purposes.

• These agrochemicals enter in the organism systemically by oral route, inhalation or by skin absorption.
• The first step is toxicity assessment to ensure that chemical is toxic or not. Likewise, pharma drugs there is a need of shot and long-term bioassays to determine the toxicity levels of agrochemicals.
• Toxicokinetic and toxicodynamic studies are also important with the determination of mode of action (MOA) to understand the toxic effect. 
• The toxicity thresholds LD50 (oral) or LC50 (inhalation or contact) can be determined.

Traditional medicines are again gaining popularity in medication because these formulations have fewer or no side effects. In present condition regarding healthcare products and therapeutics, safety establishment is must before use or treatment.

• In India, general guidelines for safety/toxicity evaluation of ayurvedic formulations issued by Central Council for Research in Ayurvedic Sciences (CCRS), Ministry of AYUSH, Govt, of India, New Delhi for drug development in the field of ayurveda popular as ‘AYUSH’ (Ayurveda, Yoga and Naturopathy, Unani, Siddha and Homeopathy).
• CCRAS have developed three comprehensive and short Guidelines focusing on drug development (Standardization and quality assurance), safety/toxicity and clinical evaluation for ready reference of investors.
• These guidelines are necessary to practice who (researchers) are working in the field of AYUSH system.
• Pre-clinical evaluations of toxicity are also performed on animals according to the guidelines suggested by AYUSH system.

We, at Dabur Research Foundation (DRF), have the expertise to undertake these toxicity studies for Pharmaceuticals, Agrochemicals, and Traditional Medicine fields for safety assessment. To conclude, toxicity is an inevitable part of drug development without safety assessment no molecule or drug will step up from pre-clinical to clinical level of therapeutic expansions.