GI tract second year

Define pharmaceutical formulation

A solution of homogeneous mixture of one or more solutes dispersed in a solvent

List the advantages of a liquid dosage form

Good patient compliance and acceptance

Good absorption and Less GI irritation

No expensive drying steps during making

Phase separation not a concern

List disadvantage of liquid dosage forms

Masking nasty taste

Susceptible to microbial contamination

Dose uniformity issues with some liquid dosage forms

Stability issue (hydrolysis of API)

Not as convenient as tablets and capsules

Packing and transport problems

Why is an API often developed as an aqueous solution?

An API in an aqueous solution offers the highest bioavailability because it bypasses the disintegration and dissolution steps required by solid oral formulations, allowing for quicker absorption.

What are the formulation components for oral solution

API

Vehicle

Co- solvent

Buffer to maintain desired pH

Sweeteners and colors

Preservatives and Antioxidants

What is a benefit of having a drug in syrup form?

masks unpleasant taste by providing sweetness

What kind of drugs are syrups useful for

water soluble

Concentrated sugar solutions are resistant to what?

microorganisms due to low water content

Why are preservatives at a minimum in sugary syrups?

Due to osmotic effects. Sugar pulls the water away from the microorganisms and without enough water the microorganisms can't grow and survive.

In low sugar con what are high osmotic gradients maintained with?

Polyhydric alcohols

Sorbitol

Glycerol

Propylene glycol

How do polyhydric alcohols work

Act as humectants and preservatives. Since low sugar concentrations don't provide the same osmotic protection as high-sugar syrups, sorbitol helps by:

Retaining Moisture: Sorbitol is a humectant, meaning it attracts and retains water, which helps keep the syrup smooth and prevents it from crystallizing.

Enhancing Preservation: Sorbitol creates a mild osmotic effect that inhibits microbial growth, giving some level of preservation even with lower sugar content.

How can crystallisation of syrups be minimised?

Polyhydric alcohols

Invert syrup

What is a humectant

A humectant is a substance that helps keep things moist by attracting and holding onto water.

Cryslatisation in syrups is undesirable why?

Texture and Consistency: Crystals make the syrup gritty and uneven, which affects its smoothness and makes it less pleasant to use or ingest.

Dosage Accuracy: Crystallization can change the concentration of the active ingredient in the liquid, making doses inaccurate. Some parts may have more or less active ingredient than intended.

Reduced Stability: Once crystallization starts, it can continue to spread, making the syrup unstable and potentially reducing its shelf life.

User Experience: A syrup that crystallizes may be harder to pour, use, or measure, impacting its convenience and user satisfaction.

What is an elixer?

An elixir is a sweetened solution of the API in a mixture of water and ethanol (up to 12-15%), known as a hydroalcoholic solution.

Why are elixirs called hydroalcoholic solutions?

Because they contain a mix of water and ethanol, making them suitable for APIs that dissolve in both water and alcohol.

What are two characteristics of elixirs due to their low sugar content?

They are less sweet and less thick.

Why are elixirs often preferred over syrups or solutions despite being less effective at taste-masking?

The hydroalcoholic mix in elixirs provides enhanced solute stability, making them more stable.

What does the alchol in elixers prevent?

Prevent the growth of bacteria and fungi. This combination also helps keep the active ingredient dissolved and evenly mixed, so it doesn't separate or degrade as quickly.

What are tinctures?

Tinctures are alcoholic or hydroalcoholic solutions containing an API or plant extracts, with high alcohol content (15-80%).

Why must tinctures be tightly stoppered and kept away from high temperatures?

Due to their high alcohol content, tinctures are flammable and need to be stored securely to prevent fire hazards.

What 4 factors affect physical stability of a pharmaceutical solution

Storage temperature

Microbial contamination leading to a change in the PH

Evaporation of volatile co solvent

Degration of compound with low stability

What can degration lead to?

Decreased drug potency (strenght)

Possible toxicity

where are otic solutions admistered to?

ear

What are the 8 components of a suspension

The API

Wetting agent

Suspending agent

Flocculating agent

Preservatives

Sweeteners

Flavours

Colorants

What are wetting agents and why are they used?

For drugs with hydrophobic surfaces the wet agent formed coating around API and reduces surface tension.

Facilitate wetting and therefore dispersion

What do suspending agents do

Increase viscosity

What is purpose of flocculating agents:

Prevents Caking: By forming loose clumps, flocculating agents help prevent the particles from settling into a hard, compact layer at the bottom, making the suspension easier to shake and use.

Improves Stability: They ensure the particles remain evenly distributed, so each dose has a consistent amount of active ingredient.

What forces are flocs held together by?

van der Waals forces

What are 3 advantages of using emulsions?

Increased API bioavailability

Increased drug stability

Prolonged drug action as the oily phase can act as a reservoir

What is aggregation

particles in a solution come together and form clusters or groups. Making is harder to resuspend compared to flocculation.

What are 2 disadvantages of using emulsions?

Thermodynamically unstable leading to possible flocculation

More complex to formulate than solutions as energy is needed in the system like mixing. On a small scale via a trituration

What are 2 types of emulsions

oil in water, water in oil

Water in oil emulsions are taken what and why

topically due to unpleasant taste.

What is an emulsifier, and what is its role in emulsions?

An emulsifier is an agent that stabilizes an emulsion, preventing the dispersed droplets from separating.

What is a surfactant, and how does it help stabilize emulsions?

A surfactant is a type of emulsifier with a hydrophilic head and a hydrophobic tail. It arranges itself in water so the tails avoid water, forming films or micelles that stabilize emulsions.

What are micelles, and how do they contribute to the stability of emulsions?

Micelles are spheres formed by surfactant molecules, where the hydrophilic heads face outward, and the hydrophobic tails are inside. They can trap the dispersed phase (like oil droplets) to create a stable emulsion.

Inadequate physical stability in emulsions can lead to the following 4:

Coalescence (irreversible leads to breaking)

Flocculation

Creaming (reversible but not desirable)

Breaking

What is malnutrition defined as?

Deficiency (interchangeably) or an excess or imbalance of energy protein and other nutrients

What can malnutrition predispose the body too?

Infections

Delayed clinical recovery

Increase in clinical complications

Inactivity

Psychological decline

decrease quality of life.

How to calculate BMI?

weight (kg) / height (m^2)

what is catabolism

Catabolism is the process by which the body breaks down complex molecules into simpler ones, releasing energy. It's a part of metabolism where large molecules like carbohydrates, fats, and proteins are broken down into smaller molecules, such as glucose, fatty acids, and amino acids.

what does nutrition support provide?

l Improve mental & physical states

l Minimise effects of catabolism

l Prevents weight loss & death from starvation

l Restore normal body tissue

l ↓ hospital stay

l Improve the quality of life

Nutrition support for those who are malnourished should be considered when?

• a BMI of less than 18.5 kg/m2

• unintentional weight loss greater than 10% within the last 3-6 months

• a BMI of less than 20 kg/m2 and unintentional weight loss greater than 5% within the last 3-6 months.