Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Title: Peptic Ulcer Disease
Description: University notes regarding peptic ulcer disease
Description: University notes regarding peptic ulcer disease
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Peptic Ulcer Disease
An ulcer is diagnosed when there is a breach in the continuity of the epithelial
lining and there is associated inflammation
...
Protective factors: -‐ Mucus layer is hydrophobic
...
Symptoms for PUD are similar to
those of duodenal ulcer, gastric ulcer and non ulcer dyspepsia
...
A Anaemia
L Loss of weight
A Anorexia
R Recent onset of symptoms
M Malaena or haematemesis
S Swallowing difficulties
Gut wall of the stomach
-‐ The stomach is lines by a single column epithelium
...
-‐ depressions in the surface of the gastric mucosa are gastric pits
...
-‐ Gastric glands contain different cell types: Mucous neck cell, parietal cell, chief
cell and enteroendocrine cell
...
-‐ They use a mechanism to secrete HCl:
1
...
2
...
3
...
4
...
The extrusion of H+ ions into the lumen of the gastric gland in exchange for K+
ions
...
Secretagogues
-‐ A substance that allowed another substance to be excreted
...
Gastric mucosal injury
-‐ Gastric mucosa becomes overwhelmed by noxious substances, e
...
hyper
secretion of HCl
...
-‐ Components of gastric juice:
-‐ Gastric acid is bactericidal and antimicrobial
...
-‐ HCO3-‐ ions are secreted by MEC in the corpus and antrum:
• PGE2 stimulates HCO3-‐ ions from MECs
...
• A pH of 7 is maintained in the vicinity of the
apical membrane
...
It acts as a lubricant
protecting the stomach from physical damage due to the rough texture of food
being churned
...
Restitution
-‐ Significant damage to the mucosa can be repaired within minutes to hours
...
-‐ Committed progenitor cells differentiate to MECs
...
Proton pump inhibitors mechanism of action
-‐ Form disulphide bonds with H+, K+, ATPase
...
-‐ Disulfide bond is irreversible
...
-‐
-‐
Rate of reaction depends on the pKa’s of pyridyl and benzimidazole
nitrogen
...
Electron releasing groups on pyridinyl ring make it more
reactive
...
-‐ Dry granulation: typically mix powders, preliminary compress using
rollers and large punches
...
Tableting journey
Mixing powders -‐> Granulation -‐> Compression -‐> Coating -‐> Packing
Excipients
-‐ Other ingredients other than the active
...
g
...
g
...
g
...
g
...
g
...
g
...
-‐ Water uptake causes tablet disintegration, by rupturing the intraparticles
cohesive forces that hold the tablet together, e
...
starch, cellulose
...
g
...
Lubricants
-‐ Compression lubricants prevent the miss adherence of powder and
promote the smooth ejection from the die after compaction, e
...
magnesium stearate
...
-‐ Flowability is important during high speed processing
...
g
...
Helps with the breaking of the tablet
...
-‐ Class 1 – High solubility and High permeability
-‐ Class 2 – Low solubility and High permeability
-‐ Class 3 – High solubility and Low permeability
-‐ Class 4 – Low solubility and Low permeability
Implications for drug bioavailability
-‐ Class 1 – dissolve and readily cross the mucosa
-‐ Class 2 – Poor dissolution, good absorption
-‐ Class 3 – Dissolve rapidly, poor absorption
-‐ Class 4 – Poor dissolution, poorly permeable
Limitations of BCS
-‐ Does not consider stability, formation and first pass metabolism
-‐ Take arbitrary limits
Three pathways of gastric acid stimulation
1) The neurocrine pathway which delivers transmitters such as
acetylcholine
2) The endocrine pathway which released hormones such as gastrin
3) The paracrine pathway which releases hormones
Gastric defensive factors
-‐ Mucus production
-‐ Bicarbonate production
-‐ Mucosal blood flow
-‐ High epithelial cell turnover
Gastric aggressive factors
-‐ H
...
pylori tests
-‐ Endoscopy
H
...
-‐ Mode of acquisition unidentified
...
-‐ The organism is able to burrow through the gastric mucous layer
...
-‐ Treatment: Amoxicillin, metronidazole, clarithromycin
...
H2 receptor agonists
-‐ Mechanism of action: block the action of histamine on the parietal cells of
the stomach, decreasing the production of gastric acid
...
-‐ Adverse effects: headache, confusing, diarrhea, and gynaecomastia
...
-‐ Therapeutic use: dyspepsia, PUD, GORD, barrretts oesphagus
...
Prostaglandin analogue
-‐ Mechanism of action: Inhibits the secretion of gastric acid by acting at the
parietial cells
...
Increases mucosal blood flow
...
Treatment of NSAID induced ulceration
-‐ Once ulcer developed discontinue the NSAID and treat
...
-‐ High dose h2 receptor agonists may be used
...
Under highly
standard conditions, 298k and 1 atmosphere of pressure
...
Amperometry
-‐ Measurement based on the detection of ions using electric current
(amperes) or change in current
...
Voltammetry
-‐ Measurement based on the securing information about an analyte by
measuring the current as the potential (voltage)
...
-‐ Sample is swept through the stationary phase (is eluted) by the mobile
phase (eluent)
...
-‐ The analyte can only move when in the mobile phase, therefore the more
time in the mobile phase the faster it moves through the stationary phase
...
Glas liquid chromatography
-‐ Used for fairly volatile materials
...
-‐
-‐
-‐
-‐
-‐
The sample is injected and vaporized by heat, passes along a column,
partitioning continually by dissolving in the stationary phase, and
evaporating into the mobile phase
...
The injection temperature should be more than the boiling point of
analytes
...
Column temperature: Column thermostatted in the oven is important in
analysis and set to the average boiling point of the mixture
...
Ions carry current between 2 electrodes
...
-‐ Electron capture detector: Mobile phase is ionized and carried current
between 2 electrodes
...
-‐ Mass spectrometer: Eluent enters mass spectrometer
...
-‐ Katharometer: Measures thermal conductance
...
Only volatiles are injected
...
-‐ Thermal desorption: Volatiles collected in absorption tubes
...
Problems
-‐ Acidic or basic compounds may show peaks with extensive tailing
...
-‐ Make chemical derivatives which are less polar and more volatile
...
-‐ Stationary phase is small particles packing into a column
...
-‐ Solvent reservoir -‐> Pump -‐> Injector -‐> Column -‐> Detector
-‐ Pump: Delivers a constant reproducible pulse free flow against back
pressure
...
Loop injection is usually used to inject a sample with the
excess passing to waste
...
-‐ Fixed wavelength – 254nm, as most
drugs have an absorption here
...
-‐
-‐
-‐
-‐
Fluorescence detectors: Selective and sensitive
...
-‐ Conductance detectors: May be used for ionic materials
...
Very sensitive
...
Generally the more polar the analyte, the longer the retention time
...
Chromatography efficiency
-‐ Peak corresponding to Gaussian curve
...
-‐ Resolution: Figure that indicates how well peaks are separated
...
The resolution of peaks is defined in terms of retention time
differences and peak widths
...
Tablets for PUD
-‐ H2 antagonist – Ranitidine
-‐ PPI – Omeprazole
Particle size reduction
-‐ Increases specific surface area, therefore higher dissolution rate and
perceived higher bioavailability
...
-‐ Methods of comminution: cutter, runner, hammer, vibration, roller, ball,
fluid energy and pin
...
-‐ Energy applied during comminution concentrates at
tip of the crack
...
-‐ Bond rupture cascasdes along regions with the most
flaws
...
Material properties
-‐ Touchness: Ability to absorb energy without fracturing
...
-‐
Surface hardness: Ability to resist hardness
...
Granulation
-‐ Granules: Aggregates of powder particles
...
-‐ Why granulate? Particles aggregate in correct proportion
...
Improve
compaction characteristics
...
Usually volatile solvent and binder
...
-‐ Low shear method: Shear granulators
-‐ High shear method: High speed mixer
-‐ Fluidised bed method: Lfuidised bed
granulator
...
Liquid
bridges form and turn to solid bridges upon cooling
...
-‐ Intra granular bonding: Adhesion and cohesion in immobile films
...
Attractive forces between solid particles
...
Power granule compression
-‐ Mechanism:
-‐ Repositioning
-‐ Deformation
-‐ Fragmentation
-‐ Densification
-‐ Attrition
-‐ Deformation of primary particles
Tablet coating
-‐ A process by which an essential dry, outer layer of coating material is
applied to the surface of a dosage form
...
Thin film of a polymer based formulation
...
Confectionary
...
Thin sugar layer
around tablet
...
Modified tablet release
...
Title: Peptic Ulcer Disease
Description: University notes regarding peptic ulcer disease
Description: University notes regarding peptic ulcer disease