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1. Introduction to pharmaceutics PHM224Y/PHC330Y
Gregory Poon, PhD, BScPhm, RPh
2. Course organization
3. Contact information Gregory Poon, PhD, BScPhm, RPhOntario Cancer InstitutePrincess Margaret Hospital
Your friendly TAs
4. What is pharmaceutics? The art and applied science of dosage form design
The interface between drug and body
A broad field that draws from many disciplines
Physical chemistry (organic and inorganic)
Engineering (chemical, material)
Deals with many aspects of interactions both inside and outside the body
Its not trivial to design and implement a dosage form that is both safe and effective for the drugs intended use!
5. Pharmaceutics is unique to pharmacy Physicians and other prescribers dont learn and apply physical pharmaceutical principles
Chemists and engineers dont learn a whole lot of biology
Anyone can read the latest review article of a disease state and play armchair prescriber, but it takes a pharmacist to know how to deliver a drug safely and effectively!
7. Logistical considerations of dosage form design Storage
Rate of degradation (expiry)
How inert is it? What is the risk for contamination?
Active vs. active vs. inert ingredients
Physical appearance, taste, smell, tactility, size
For a powder, how well does it flow?
8. What you must know to design a dosage form Physicochemical properties of the drug
Solubility, acid/base, solid state behaviour
What is the intended site of action?
Where/how well is the drug absorbed?
What is the intended onset of action?
Immediate-release, sustained-release, pulse releases
9. Example: estrogen Indication: hormone replacement therapy for treatment of symptoms of menopause
Molecule administered is
Transdermal patch (Estraderm, etc.)
Transdermal gel (EstroGel)
Vaginal ring (Estring)
10. Some questions and issues About the drug
Aqueous solubility, pKa, partition coefficient
Chemical stability in solution
About the dosage form
Stability in storage
About the biopharmaceutics
Extent of absorption
Intended use: topical vs. systemic?
11. Each dosage form caters to a different need Compressed tablet
Contains micronized estradiol
Micronization improves dissolution
1 to 2 mg/day po
Estradiol is highly metabolized
Bypasses first-pass metabolism
Patch: 0.05 to 0.1 mg/day, applied twice weekly
Gel: 0.75 mg/day
Topical application of estradiol for local symptoms
Average 7.5 g/day ? 90 days
12. A list of dosage forms Solid dosage forms
Capsules (hard, soft)
Ointment, cream, gel, etc.*
Liquid dosage forms
Many administration routes
IV, IM, SC, etc.
Rectal, vaginal, urethral