NIPER JEE flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Lipinski rule of five

Predicts oral drug-likeness: molecular weight ≤ 500 Da, logP ≤ 5, hydrogen-bond donors ≤ 5, hydrogen-bond acceptors ≤ 10. Two or more violations predict poor absorption.

Bioisostere

A functional group replaced by another of similar size, shape, or electronics that retains biological activity, such as replacing a carboxylic acid with a tetrazole to improve metabolic stability.

Prodrug

A pharmacologically inactive derivative that is converted in the body to the active drug, usually to improve absorption, stability, or targeting. Ester prodrugs are hydrolyzed by esterases.

Competitive inhibition

The inhibitor binds reversibly at the substrate site, raising apparent Km while leaving Vmax unchanged; the effect is overcome by increasing substrate concentration.

Therapeutic index

Ratio of the median toxic dose to the median effective dose (TD50/ED50). A narrow index means small dose changes can cause toxicity, so monitoring is needed.

Volume of distribution

Apparent volume relating amount of drug in the body to plasma concentration (Vd = dose/C0). Large values indicate extensive tissue distribution; small values indicate plasma confinement.

Half-life

Time for plasma concentration to fall by half, calculated as 0.693 × Vd / CL. It determines dosing interval and time to steady state (about four to five half-lives).

First-pass metabolism

Presystemic elimination of an orally absorbed drug by gut wall and liver before reaching systemic circulation, reducing oral bioavailability relative to intravenous administration.

Beer-Lambert law

Absorbance equals molar absorptivity times path length times concentration (A = εbc). Linear only at dilute concentrations, so calibration curves must be validated.

Resolution in HPLC

Separation between two adjacent peaks, Rs = 2(t2 − t1)/(w1 + w2). A value of at least 1.5 indicates baseline separation suitable for quantitation.

Limit of quantitation

The lowest concentration measurable with acceptable precision and accuracy, estimated as 10σ/S where σ is the standard deviation of the response and S the calibration slope.

ICH Q2 validation

Guideline listing analytical validation parameters: accuracy, precision, specificity, linearity, range, detection limit, quantitation limit, robustness, and system suitability.

Shikimic acid pathway

Biosynthetic route in plants and microorganisms producing aromatic amino acids and precursors of phenylpropanoids, coumarins, lignans, and flavonoids.

Isoprene rule

Terpenes are built from C5 isoprene units: monoterpenes C10, sesquiterpenes C15, diterpenes C20, triterpenes C30, and tetraterpenes C40 such as carotenoids.

Cardiac glycosides

Steroid glycosides such as digoxin that inhibit Na+/K+-ATPase, raising intracellular calcium and increasing contractility; they have a narrow therapeutic index.

Dragendorff reagent

Potassium bismuth iodide reagent giving an orange-red precipitate with alkaloids, commonly used as a spray or spot test for alkaloid detection in plant extracts.

Polymerase chain reaction

In vitro amplification using thermal cycling: denaturation near 95 °C, primer annealing near 55 °C, and extension at 72 °C, doubling target DNA each cycle.

Hybridoma technology

Fusion of an antibody-producing B cell with an immortal myeloma cell to create a hybridoma that secretes monoclonal antibody indefinitely in culture.

Western blot

Technique separating proteins by SDS-PAGE, transferring them to a membrane, and detecting specific proteins with labeled antibodies; used to confirm protein expression.

CRISPR-Cas9

Genome-editing system in which a guide RNA directs Cas9 nuclease to a target sequence adjacent to a PAM, creating a double-strand break repaired by NHEJ or HDR.

Higuchi release model

Describes drug release from matrix systems as cumulative amount proportional to the square root of time, reflecting diffusion-controlled release from a porous matrix.

Osmotic pump

Delivery system using osmotic pressure to push drug solution through an orifice at zero-order rate, independent of gastrointestinal pH and motility.

Sterility assurance level

Probability that a device or product is non-sterile after sterilization; for sterile products the accepted level is 10⁻⁶, validated with biological indicators.

Carr's index

Flowability measure: (tapped density − bulk density)/tapped density × 100. Values under 15 percent indicate good powder flow; above 25 percent indicates poor flow.

HLB system

Hydrophilic-lipophilic balance scale for surfactants: values 3-6 favor water-in-oil emulsions, 8-18 favor oil-in-water emulsions, guiding emulsifier selection.

Naranjo scale

Ten-question causality assessment tool scoring adverse drug reactions as definite, probable, possible, or doubtful based on temporal relationship, dechallenge, rechallenge, and alternatives.

Phase I trial

First-in-human study in 20-80 subjects, usually healthy volunteers, designed to determine safety, tolerability, maximum tolerated dose, and pharmacokinetics.

Tanimoto coefficient

Similarity metric for binary fingerprints calculated as shared bits divided by total distinct bits; values above 0.85 often indicate similar biological activity.

Molecular docking

Computational method predicting ligand binding pose and score within a protein pocket; redocking RMSD below 2 Å validates the protocol before virtual screening.

QSAR model

Quantitative structure-activity relationship linking molecular descriptors to biological activity, validated by internal cross-validation and external test-set prediction.

Compulsory licence

Authorization granted by a government allowing a third party to manufacture a patented drug without consent, typically after three years and on public health grounds.

EOQ

Economic order quantity minimizing total inventory cost: square root of (2 × annual demand × ordering cost / holding cost per unit).

Schedule M

Part of the Indian Drugs and Cosmetics Rules specifying good manufacturing practice requirements for premises, plant, and quality control of pharmaceutical products.