Hormonal drug delivery Flashcards
Amino acid derivatives
- Route of administration
Orally route
- Derived from amino acids e.g tyrosine
Example
- Dopamine, thyroxine, hydrocortisone
Cmax and Tmax
Cmax
- Max concentration achieved in the plasma after absorption
Tmax
- Time at Cmax
AUC
Extent at which a drug is absorbed
- Area under the curve
Therapeutic range
Concentration of the drug between the max safe concentration and minimally effective concentration
Multiple oral dosing
Giving multiple doses to keep concentration of drug within therapeutic range
Dosage given when concentration starts to decline
Amino acid derivatives
- Drug factos
Potent
- Lose dose required
Low dose drug requires bulking
- Excipeients
Excipients
Given with small dose of drugs
- Diluents
- Surfactants
- Lubricant
- Disintegrants
Local delivery
Site of administration is the site of action
- Rapid onset of action
- Less drug required—> Avoids side effects as it is not absorbed into the blood stream.
Local corticosteroids
- Examples
Given locally to avoid systemic side effects
Intrarticular injection- Tennis elbow Creams- Eczema Inhaler- Asthma Eye drop- Inflammation Suppositories- Haemorrhoids
Insulin
- Drug factors
- Biopharmaceutical factors
Large peptide hormone
- Cannot be given orally as it will not be absorbed
Differences in insulin
Onset
Peak
Duration
Route
- Inhaled
- Subcutaneous
Long and short acting insulin
Long acting
- Solution in syringe
- Precipitates and aggregates in fat then separates in blood stream
- The separation of the particles is the rate limitting step
Short acting
- Rapid analog that is given in its simplest form
Insulin pump of rapid analog
Delivers sustained rapid analog throughout the day
Pulmonary route
- Systemic
Larger surface area
- High absorption probability
Thin epithelial barrier
- Small diffusion barrier for drugs
Good blood supply
- 100% cardiac output
Avoids GI harsh environment and first pass hepatic metabolism
Afrezza
Inhaled insulin
Rapid acting, taken at the start of each meal
Along side long acting insulin injections
Sex hormones
- Drug factors
- Biopharmaceutical factors
- Therapeutic factors
Lipophilic
Variable oral administration
- First pass hepatic factors
- Short half life
System effects wanted
Systemic delivery of sex hormones
Done to increase bioavailabity and gives sustained release
Examples
- Parenteral [IM injection, implant]
- Transmdermal
- Intranasal spray
- Buccal
Oily injections
IM injection- Gives sustained release
Example: testosterone formulation
- Adds ester group to decrease water solubility and deactivates the molecule
- Activated through hydrolysis (pro-drug)
Nexplanon
Subdermal implant of etonogestrel
- System delivery
Releases hormone very slowly
- Removed after 3 years
Transdermal estradiol patch
Drug diffuses across the skin into the blood stream.
Intranasal administration system
- Advantages
Advantages
- Large surface area
- Highly vascularised
- Avoids first pass
- Good bioavailability if LMW
Intranasal administration system
- Disadvantages
Mucociliary clearance
Metabolic activity
Poor bioavailability if HMW
Buccal administration [sex hormone]
- Systemic
Mucoadhesive testosterone buccal delivery
- Twice daily
- Absorbed in the blood stream of the mouth.
- Gives sustained release
Vaginal gel
- Progesterone
Local delivery
- Crinone
Gives sustained release and has good compliance
Vaginal ring
Releases estradiol over 90 days
- Acts locally
Vaginal pessary
Estradiol given in vaginal tablets
- Local delivery
Intra-uterine device
Example: Mirena, Levosert
Inserted into the uterine cavity
- Local action
- Levonorgestrel
Eicosanoid hormones
Lipid derivate hormones
- Prostaglandins E2
Routes
- Vaginal gel
- Vaginal pessary
