Paper I — 2023 July (Supplementary) (2010 Scheme) — Q4
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Paper I
2023 July (Supplementary) (2010 Scheme) · 40 marks · 120 min
Question
Special drug delivery systems
Q43 marksShort Notes
Answer
Special drug delivery systems are formulations designed to control the rate, site, or timing of drug release, improving efficacy and reducing adverse effects compared to conventional dosage forms.
Types, with examples:
Controlled/sustained-release — release drug at a predetermined rate over an extended period, reducing dosing frequency and maintaining steady plasma levels (e.g. sustained-release nifedipine, theophylline).
Targeted drug delivery (liposomes, nanoparticles) — direct the drug preferentially to a target tissue, reducing systemic toxicity (e.g. liposomal amphotericin B — reduced nephrotoxicity compared to conventional amphotericin B).
Transdermal drug delivery systems — deliver drug continuously through the skin, bypassing first-pass metabolism and maintaining steady levels (e.g. nitroglycerin patch, fentanyl patch).
Novel ocular/implantable systems — sustained local delivery avoiding repeated dosing (e.g. ocular inserts, subdermal contraceptive implants).
Advantages: improved patient compliance (reduced dosing frequency), maintenance of steady therapeutic plasma levels (avoiding peak-related toxicity and trough-related loss of efficacy), reduced systemic adverse effects through targeting, and protection of labile drugs from degradation.
