Unit 4 Flashcards
(87 cards)
What are the benefits of using solid dosage forms?
- Dose accuracy
- Stability of the drug
- Portabilty
- Uniformity of dose
- Reproducibilty
- High mechanical strength
- Tamper resistance
- Masking of taste, odour
- Easy to pack, handling and transportation
What are the disadvantages of using solid dosage forms?
- Not suitable for unconscious patients.
- May be difficult to swallow (dysphasia)
- Formulation complications
- Not preferable for acid labile and stomach irritant drugs.
What are the benefits of using liquid dosage forms?
- Easy to swallow
- Easy to manufacture
- Fast absorption
- Improves bioavailability
- Less processing steps
- Less excipients required as compared to tablets.
What are the limitations of using liquid dosage forms?
- Non uniformity of dose
- Prone to microbial attack
- Bulky
- More chance of loss by the breakage during shipping & transportation.
- Unsuitable for unpleasant taste & obnoxious odour drugs.
- Less stability.
What are the benefits of using semisolid dosage forms?
- Easy to use
- More stable than liquid dosage form.
- Avoids first pass metabolism.
- Local action of drug on affected area.
- Patient convenience (easy to apply and remove).
What are the limitations of using semisolid dosage forms?
- Difficult to handle.
- Chances of contamination (application with finger).
- More prone for environment to get affected.
- May cause staining & irritation.
What are the benefits of using gaseous dosage forms?
- Easy to handle & convenient.
- Withdrawal of dose without contamination.
- Environmental of unstable drug.
- Provides medication to local areas.
- Dose adjustments possible
- Tamper proof
What are the limitations of using gaseous dosage forms?
- Expensive
- May create environmental hazards
- Dosing is not reproducible
- Not reliable performance
- Limited safety.
Why are drug substances often combined with additives?
To ensure precise dosing and to achieve the desired therapeutic effect.
What is the importance of selection of excipients in drug formulation?
Excipients can alter the therapeutic properties of the drug.
What is a common solution for handling low-dose medications?
Preparing dosage forms such as tablets or capsules with bulking agents (diluents).
What are the benefits of controlled /extended release dosage forms?
They allow reduced frequency of administration without sacrificing efficiency.
What are the overall aim of dosage form design?
To increase stability of drug substances, extend shelf life, ensure accurate dosing, and deliver drugs in a suitable form.
What are the stages of involved in the development of dosage forms?
1) Preformulation
2) Drug product formulation development.
3) Manufacturing
What are biological properties of a drug?
This relates to its ability to get to a site of action and elicit a biological response.
What is the solubility of a drug classified as and what is its significance?
This is classified in terms of the solvent required to solubilise 1g of the drug at a specified temperature, which is determined by the kinetic solubility and the equilibrium solubility.
This significantly affects the bioavailability of the drug.
How is kinetic solubility of a drug determined?
1) Dissolving the drug in dimethyl sulfuric (DMSO).
2) Add water until a precipitate forms.
3) Samples are filtered to remove the precipitate.
4) Concentrations are measured using UV or LC/MS.
How is thermodynamic and equilibrium solubility determined and what is its importance?
1) Dissolved in an aqueous medium for a prolonged period of time until an equilibrium is achieved under constant agitation and desired temperature.
2) Sample is filtered
3) Drug concentration is analysed using UV or LC/MS.
This helps to identify the polymorphic and amorphous forms of the drug.
What does the partition coefficient (oil/water) indicate and how is it determined?
It indicates the lipophilicity of a drug and is determined by the shake flask method using 2 immiscible solvents: water (or phosphate buffer at pH 7.4) and octanol. Defined as the ratio of un-ionised drug distributed between the organic phase (C organic) and aqueous phases (C aqueous) at equilibrium.
Ko/w= (C organic/C aqueous)
How does the drug’s Ko/w value affects its absorption?
Higher Ko/w values increases a drugs ability to cross cell membrane due to its lipophilicity, which enhances passive absorption. However, too high of a lipophilicity can lead to low solubility. Thus, a balance between lipophilicity and solubility is ideal for optimal drug absorption.
Why is dissolution important in drug absorption?
It reveals the rate and extent of a drugs absorption in the body. It is the process where the drug substances (solute) dissolves into the solution, with the dissolution rate indicating how fast it dissolves in a given medium.
What is the primary objective of stability testing in drug development?
Provides info such as processing, storage, and absorption at gastrointestinal mucosa. Preformulation stability studies cover solid-state, solution phase stability, physical stability & photostability studies. Solid state stability testing are performed when samples are exposed to extreme temp and humidity -provides info on possible routes of degradation, & degradation products of the drug substances.
What is drug formulation, and what does the process involve?
Process of determining the best way to deliver and Active Pharmaceutical Ingrediant by combining it with inactive substances to create a final product. During development, formulations are tested for stability, efficiency, & processability. Most drugs are developed as tablets/capsules, with some s njections, depending on drug-specific needs. After formulation, preclinical + clinical studies assess safety + efficacy, followed by manufacturing under GMP.
What function does the excipient binders have?
Substances that promotes cohesiveness of powders thereby providing the mechanical strength to the tablet.