Question

Drug discovery and development involves a number of distinct stages each having a defined aim and typical set of research studies that are undertaken. State one stage of drug discovery and development (i.e. prior to drug registration and marketing), identify the aim of this stage, and discuss the studies that occur during this stage to achieve the stated aim.

Answer 1

DRUG – generally defined as a chemical substance with known structure unlike a nutrient or essential dietary ingredient when administered to a living organism produces some biological effects.

Drug development can be studied under 2 phases – Discovery phase and development phase.In the former phase -identification of a new agent that can be used therapeutically successfully and in the later phase – the identified compound is tested whether it is safe and efficient for clinical uses ,also finalizing the dosage,formulations etc.

PATHWAYS OF DRUG DEVELOPMENT ARE FOLLOWS;

Drug discovery

Pre clinical development

Clinical development

DRUG DEVELOPMENT – STARTS in a laboratory and scientists coming from different functional areas of biology works together for the studying a particular disease,the reason behind this disease – i.e both cellular and genetic factors governing this disease.Then comes the most important step in drug development – identification of the target where the drug have to act for this disease and the resource of the drug that can act on this particular target and thus curing the disease – so simply the step is identification of target for the drug and resource of the drug.

This involves 4 steps ; the most important step being the target identification related with a specific disease ,in which the drug will act.

TARGET SELECTION

Most common drug targets are - nuclear receptors, ion channels, hormones and factors, enzymes, G-protein coupled receptors etc.

Target Identification

Usually drugs acts on the cellular level or genetic level factors causing the specific disease when consumed by the diseased person and thus leads to the curing of disease.Scientists study on this interaction between the drug and drug targets based on the available information and how they can influence the disease.Based on this studies compounds are identified that can interact with the drug targets and thereby helping in treating the disease.This is done at both cellular and genetic levels.

Drugs when consumed usually attacks on this specific targets that are related with that disease.

At genetic level studies scientists employ genomics for studying genes and their function.After obtaining the required sequential informations regarding genes related to drugs and drug targets – they exploit this genetic study based results for identifying drug targets.

Proteomics

Proteomics helps in studying the drug targets as it has been observed that most drugs acts on proteins.Protein expression levels in both diseased and normal conditions are compared with the help of proteomics and analysis is done on drug targets and the particular disease with the help of proteomics.

Bioinformatics

It helps in various stages like target identification,computer screening of the chemical compounds also in pharmacogenomics.

Helps in comparing the genomes of pathogenic and non – pathogenic strains of microbes related with the disease and thereby helps in identifying and studying the genes and proteins involved.

TARGET PRIORITIZATION AND VALIDATION

Before fixing a target; scientists use all the technologies and informations available to analyze and compare all the drug targets association with the specific disease and how they are affecting the biological and chemical compounds in the body.

All type of tests are done to check that the effects produced by that specific drug on a specific drug target are desirable for the curing of the disease and no harmfulness must be caused to the drug consuming person due to this interaction(side effects are also studied ).

Thus through all this analysis they can identify compounds that have the desired effect on the target selected.After choosing the target it will be validated.

TARGET VALIDATION DONE BY PERFORMING;

In vitro tests – to confirm that any change in the target will cause change in the disease.

In vivo tests – using animals the results of in vitro tests are confirmed.

This results will help in predicting the profile of new drugs and also helps in determining whether this drugs will be effective or not.