Jawaharlal Nehru Technological University Hyderabad B.Pharmacy IV Pharmaceutical Regulatory Science Previous Question Paper (September-2021 - R17)

The new drug development process is a multi-stage sequence designed to ensure safety and efficacy before market approval. The process follows this progression:

1. Discovery and Development: Identification of a candidate molecule through target validation and lead optimization.
2. Pre-clinical Research: In vitro and in vivo studies to assess biological activity and initial safety profiles.
3. Investigational New Drug (IND) Application: Submission of data to regulatory authorities to request permission to begin human testing.
4. Clinical Trials: Phase I (safety in healthy volunteers), Phase II (efficacy and dosage in patients), and Phase III (large-scale confirmation of therapeutic benefit).
5. New Drug Application (NDA) / Biologics License Application (BLA): Comprehensive submission of all clinical and non-clinical data for regulatory review.
6. Regulatory Review: Evaluation by agencies like the FDA or CDSCO for approval.
7. Post-marketing Surveillance (Phase IV): Ongoing monitoring of safety and side effects in the general population.

Drugs exert their pharmacological effects by interacting with specific molecular targets within the body. The primary targets of drug action include:

• Receptors: These are specialized protein molecules located on the cell surface or within the cell that bind to endogenous ligands. Drugs act as agonists (activating the receptor) or antagonists (blocking the receptor).
• Enzymes: Many drugs function by inhibiting or activating enzymes. Enzyme inhibitors, such as ACE inhibitors or HMG-CoA reductase inhibitors, prevent the formation of specific metabolites by binding to the enzyme's active site.
• Ion Channels: Drugs can modulate the flow of ions across cell membranes by acting as channel blockers or modulators. Examples include calcium channel blockers used in hypertension.
• Transporters: These proteins facilitate the movement of ions and molecules across membranes. Drugs can inhibit these transporters to alter cellular concentrations of neurotransmitters or nutrients, such as selective serotonin reuptake inhibitors (SSRIs).
• Nucleic Acids: Some drugs, particularly anti-cancer and anti-viral agents, target DNA or RNA to interfere with replication or protein synthesis, for example, alkylating agents.