Pharmaceutics and Pharmaceutical Technology
Core concepts
This domain covers dosage-form design and manufacture. Candidates must know the biopharmaceutics classification system (BCS I–IV) and how solubility and permeability dictate formulation strategy, plus the excipients and their roles (diluents, binders, disintegrants, lubricants, glidants, surfactants, preservatives). Understand the manufacturing unit operations: granulation (wet/dry), tabletting (direct compression vs granulation), coating, capsule filling, and the quality attributes of each (hardness, friability, disintegration, dissolution, content uniformity). Sterile products require knowledge of isotonicity, pyrogens, sterilisation methods (moist heat 121 °C, dry heat, filtration 0.22 µm, radiation, aseptic processing) and the difference between sterilisation and depyrogenation. For compounding, know the meaning of 'freshly prepared', geometric dilution for potent powders, and the purpose of suspending and emulsifying agents.
Traps
Examiners exploit confusion between disintegration and dissolution (a tablet can disintegrate but fail to dissolve), between sterilisation and disinfection, and between isotonic and isosmotic. Another trap: assuming a sustained-release formulation can be crushed - it cannot, and dose dumping is the risk. Bioequivalence questions test that two products must match rate and extent of absorption, not merely contain the same dose.
Rule of thumb
For any formulation problem, identify the limiting BCS factor first: low solubility → particle-size reduction, salt formation, solubilisers; low permeability → permeation enhancers. For sterile products, ask 'is the product heat-stable?' - if yes, moist heat is first choice; if no, filtration or aseptic processing.
Worked example
A poorly soluble BCS II drug for oral tablets: reduce particle size and consider a solid dispersion or salt form; choose a disintegrant and a lubricant that will not retard dissolution; set a dissolution specification as the key quality control test.