These notes encompass all of the information necessary for a student studying Option D of IB Chemistry. Every topic from D.1 - D.9 is included in these notes with detail on every aspect.
D.1 PHARMACEUTICAL PRODUCTS AND DRUG ACTION BIOAVAILABILITY: the fraction of the administered dosage of a drug that enters the bloodstream, accessing the site of action
MEDICINES and DRUGS are chemical substances that do one or more of the • POLAR DRUGS: soluble in aqueous body, but poorly absorbed due to inability to cross cell membranes
following: • NON-POLAR DRUGS: these drugs are poorly absorbed because they are insoluble in aqueous body fluids
• alter incoming sensory sensations • for HIGH ABSORPTION: largely hydrophobic but have solubility in aqueous solutions
• alter a person’s mood or emotions
• alter the physiological state of the body • SOLUBILITY: ability of functional group to ionise and form hydrogen bonds (ex, carbonyl, hydroxyl, group)
• including consciousness and coordination • functional groups which enhance the lipid solubility are non-polar, cannot ionise or hydrogen bonds (ex, phenyl group, hydrocarbon chain)
• ASPRIN: carboxylate, phenyl group, ester group
MEDICINES (PHARMACEUTICAL DRUGS) are substances used for the
• phenyl group = non solubilise
treatment or prevention of disease
• solubility of asprin can be increase by reacting it with aqueous NaOH = ionic salt
MEDICINAL properties depend on their functional groups in their molecules
• drugs with acidic or basic groups can be modified to form an ionic salt
medicines contain beneficial drugs
beneficial effect of medicines = THERAPEUTIC EFFECT
examples: asprin, penicillin, ibuprofen
THERAPEUTIC WINDOW
• the relative margin of safety of a drug
• wide therapeutic window = safer drug, wide margin between doses that are effective and doses that are toxic
METHODS OF DRUG ADMINISTRATION DRUGS
• narrow therapeutic window = only a small increase in the effective dose may product toxic effect
ORALLY
• ingested by mouth
THERAPEUTIC INDEX
• drugs with many polar groups are generally water soluble
• the ratio between the dosage of a drug that causes a toxic(or lethal) effect and the dosage that causes a
RECTALLY
therapeutic effect
• in enemas
• ED50 (median effective dose) = dose that produces the therapeutic effect in 50% of the population
PARENTERALLY
I
• TD50 /LD50 (median toxic/lethal dose) = dose that is toxic/lethal to 50% of the population
• injected under the skin
SUBCUTANEOUS INJECTION
• under the skin
chemical compounds are unstable in DRUG DEVELOPMENT STEPS
the highly acidic gastric juice 1. drug is synthesise int he laboratory
INTRAMUSCULAR INJECTION
• into the muscle tissue 2. drug is tested on animals to determine the LD50
INTRAVENOUS INJECTION 3. drug is tested on humans - half of the group are given the real drug, the other half
• blood stream are given a placebo
INHALATION PLACEBO
• breathed in through the nose or mouth • administering an inert substance
• volatile or highly dispersed drugs • patients and administrators do not know who has received the drug and who has
TRANSDERMALLY received the placebo
• applied to the skin in form patches, ointments PLACEBO EFFECT
• non-polar of compounds • when the body is fooled into healing itself naturally
• FACTORS THAT MUST BE DETERMINED DURING CLINICAL DRUG TRAILS
• risk : benefit ratio
• unwanted side effects
• drug tolerance (how much a person needs before it is effective)
, D.2 ASPRIN AND PENICILLIN DISCOVERY OF PENICILLIN
SOLUBILITY OF ASPIRIN
• group of antibiotics used to treat a range of bacterial infections
• to make aspirin soluble, it needs to react with aqueous NaOH
• are derived from Penicillium fungi and can be taken orally or via injection
forming an ionic salt
SYNTHESIS OF ASPIRIN • was discovered in 1928 by Sir Alexander Fleming, whilst working with bacteria cultures
• the producet is SOLUBLE ASPIRIN (increase solubility)
• ASPIRIN (acetylsalicylic acid): produced by reacting salicylic acid with • he noticed that a fungus (Penicillium notatum) had contaminated some of his cultures and left a
ethanoic anhydride clear region where no bacteria colonies were growing
• the reaction produces aspirin and ethanoic acid
• salicylic acid is converted to aspirin through esterification (condensation PENICILLIN MODE OF ACTION
reaction) • Penicillins (are beta-lactase antibiotics) are characterised by the presence of a beta-lactam ring
• when water is added to SOLUBLE ASPIRIN = dissociates to • the beta-lactam ring is the
form sodium ions and acetylsalicylate ions part of the molecule
• ionic salts of aspirin are more soluble in water as they form responsible for penicillin’s
stronger ion=dipole interactions with water anti-bacterial properties
• concentrated H2SO4 is added to the reaction mixture which is warmed
gently
• the product is cooled to form crystals which are then suction filtered and
washed with cold water
• however, converting aspirin to ionic salt does not increase its
bioavailability as the acetylsalicylate ion is converted back to un- • the bond angles in the ring are reduced to 90 degrees celsius which puts a strain on the bonds
• aspirin has a low solubility in cold water so this process removes the • due to the strain in the beta-lactam ring, it breaks relatively easily
ionised form in the stomach’s acidic environment
soluble acids but not the aspirin
• only way to increase bioavailability is to administer intravenously
• aspirin is purified in RECRYSTALLISATION - impure crystals are • beta-lactation antibiotics interfere with cell wall formation in bacteria by inhibiting the enzymes
dissolved in a small volume of hot ethanol responsible for creating cross-links in the cell wall
• water is then added and the solution is cooled slowly and then chilled USES OF ASPIRIN • when the beta-lactation ring comes into contact with bacteria, the ring opens and binds
• the acetylsalicylic acid will recrystallise, unreacted salicylic acid will remain • mild analgesic (painkiller) - block sensation of pain at the source irreversibly to the anime responsible for catalysing cross-linking in the cell wall of the bacteria
isolated in solution • block the action of enzymes that produce prostaglandins • water enters the cell, increasing the osmotic pressure inside the cell, causing it to burst
• prostaglandins (involved in transition of pain impulses to brain) are
PURE ASPRIN prevented from being synthesised = reducing or eliminating pain
• melting point between 128-140 degrees Celsius ANTIBIOTIC RESISTANCE
• infrared spectrum of aspirin (has no C=O in esters or phenol compared to • modifying the side-chain results in penicillins that are more resistant to the penicillinase enzymes
• anticoagulant - prevent blood clotting (and so heart attacks and
salicylic acid peak) • the penicillinase enzyme could deactivate the original form of penicillin, penicillin G
strokes)
• anti-inflammatory properties, asprin is taken for arthritis and
rheumatism
SIDE EFFECT
• causes bleeding of lining of stomach
• this is increased by drinking alcohol = SYNERGISTIC EFFECT (if
• the different side-chains reduce the occurrence of penicillin resistant bacteria
two drugs increase each other’s effectiveness when taken together)
• modified penicillins are able to withstand the action of penicillinase enzyme
• the side chain can also be modified to give increased resistance to breakdown by stomach acid,
which means that the antibiotic can be taken orally
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller parmisyahoo. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.48. You're not tied to anything after your purchase.