intro to pharmaceutics Flashcards
what is pharmaceutics?
- the science of converting drugs into medicines
- & the study of drug formulations and the processes by which they are designed, manufactured and delivered to the body.
Pharmacy mediates between what…
life and death
good versus harm
safety versus efficacy
what is the point of pharmaceutics
to take a drug (usually a powder), and formulate and manufacture a product that is effective, safe and of high quality
what do we need to consider in pharmaceutics?
solubility, dose, route, site of action, stability
-> Maximising therapeutic activity
-> Minimising side effects
what do we need to ensure in pharmaceutics
that the drug is delivered using the right dosage form, such that the correct amount of drug reaches the correct site at the right time
What is a dose?
The required amount of a drug to have a therapeutic effect with minimal unwanted effects
- Different drugs have very different doses & may differ by different routes:
e.g: Salbutamol to lung: mcg, vs tablets: mg
lower dosage needed as directly to lungs via inhaler rather than tablets.
what differs a drug from a medicine
→ a medicine is a formulated drug product / drug delivery system that contains an active drug substance.
- Medicine is composed of drug (the active ingredient) and excipients (inert ingredients).
→ A drug is the pharmacologically active ingredient in a medicine
e.g. paracetamol is a drug, while capsules are medicines
what is a formulation?
the presentation of a therapeutic substance (drug, active pharmaceutical ingredient) in a manner in which it can be suitably administered to a patient to achieve a predictable and reproducible therapeutic response
→ this may require the inclusion in the product of pharmacologically inert ingredients (excipients)
- example of an excipient in a liquid medicine: starch, sucrose, thickening agents
Sometimes the amount given is not the amount that gets to the intended site of action
Why?
think of a tablet
- excreted
- metabolised e.g. in portal vein
- possible: didn’t dissolve, therefore wasn’t absorbed
products must be what 3 things?
- safe
- effective
- appropriate quality
what are examples of organoleptic properties
taste, smell, appearance, mouth-feel, texture of medicines are very important - many drugs have a bitter taste, and need to be formulated with flavours or sweetening agents to be acceptable to patients.
excipients short definition
any substances other than the active drug in the dosage
excipient definition properly
Any substances other than the active drug which have been appropriately evaluated for safety and are included in a drug delivery system to either aid the processing of the drug delivery system during its manufacture, protect, support or enhance stability, bioavailability, or patient acceptability, assist in product identification, or enhance any other attribute of the overall safety and effectiveness of the drug delivery system during storage or use
important characteristics of excipients
- inert, safe & high quality
- not wholly inactive though
what are some of the functions of excipients?
they solubilise, suspend, thicken, preserve, emulsify, modify dissolution, improve the taste and appearance of medicines.
types of excipients *for 2nd year
e.g. for solid dosage forms (tablets)
- PRIMARY
- Fillers (diluents), binders, disintegrants, lubricants, glidants
- Comprise the major part of a formulation
- Hold the key to its success - SECONDARY
- Film coating, colours, flavours, sweeteners, wetting agents
- Stability, appearance, and performance
what is a molecule defined as?
a very small, chemical species held together by covalent chemical bonds vs a particle - contains billions of molecules held together by intermolecular forces
give examples of dosage forms available for diff administration routes e.g. tablets for oral
ORAL - tablet, capsule, powder, solution…
RECTAL - creams, enemas, foams…
VAGINAL - ointments, pessaries…
NASAL - solution, inhalations…
OCULAR - inserts, lenses…
AURAL - suspensions…
PULMONARY (respiratory) - aerosols, inhalations…
TOPICAL - creams, ointments, patches…
PARENTERAL - injections, implants…
URETHRAL - solutions…
