L3-the science of formulation- into to dosage forms and excipients

what is a dosage form?

the physical form in which a medication is produced and administered, it includes the drug and other ingredients that help deliver the medication effectively

give examples of types of dosage forms

tablets

capsules

liquids

topicals

inhalers

why do we need dosage forms

in order to get the right drug into the right place at the right dose at the right rate as patient cant be expected to do this themselves

example- intravenous injections = seconds ,enteric -coated formulations= several hours

what are the requirements dosage forms must meet ( 7)

1. dosing accuracy- deliver the correct amount of API+ minimise toxicity

2.stability-must protect the drug during its shelf life from degradation due to light, moisture , temperature or oxidation + shouldn't react with container or delivery device

3.bioavailibility- must release the drug in a way that it reaches the intended site of action

4. safety-non toxic, free from contamination, no adverse effects

5.patient acceptability- palatable, taste and odour masking + easy to administer

6. manufacturability- must be feasible to produce consistently at scale

7. regulatory compliance - should meet pharmacopeial standards

what are the different type of solid oral dosage forms

tablets

caplets

capsules ( hard and soft shelled )

effervescence tablets

granules/powders

Oro dispersible tablets and films

explain characteristics of tablets

hard compressed powder

usually round or ovals

stable, cost effective and customisable release forms ( using coating or layered tablets )

cons: can be hard to swallow and may have objectionable taste if uncoated - may not appeal to patients

explain the characteristics of caplets

same as tablets just easier to swallow due to being oval and smooth

explain the characteristics of capsules

the formulation is contained within a shell of gelatine ( or veg alternative made of plant derived polysaccharides ) which dissolves in the stomach

hard-shelled= contain dry formulations including powders granules and pellets

soft shelled =used for oils or drugs that are difficult to formulate as solids

explain the characteristics of effervescence tablets

uncoated tablets that with an acid react rapidly in water by releasing co2

very rapid tablet dispersion

can be made palatable with addition of flavour and sweeteners

packaging is critical for stability must protect from moisture

explain the characteristics of orodispersible tablets

solid dosage forms that dissolve rapidly in the oral cavity without water

dosage form disperses in saliva

some absorption occurs before the gastrointestinal tract

the tablet formulation are ready to take up water/porous and flat - good for patients with difficulty in swallowing

cons: fragile and difficult to handle specific peel-off packaging

flavoured

explain the characteristics of sublingual and buccal dosage forms

tablets or film designed to be placed under the tongue or between the gum and cheek - straight into circulation = rapid effect

bypass the stomach and the liver

list all the liquid oral dosage forms

solutions- clear liquid preparation with API and excipients dissolved in a solvent

emulsion- stabilised oil-in-water/water -in oil dispersions may contain dissolved solid

suspensions ( used for poorly soluble drugs )- one or more API dissolved as solid particles in a suitable vehicle e.g. purified water and thickening gums

syrups- concentrated aq sugar solutions with dissolved API and excipients, flavoured is good for masking taste

elixirs - nicely flavoured, sweetened clear solutions of nauseous drugs in aq alcohol

linctus -viscous dosage forms prescribed for the relief of coughs coating the throat, contains a high proportion of syrup and glycerol

drops- concentrated solutions administered in small volumes, usually for paediatric use

what are parenteral dosage forms ( include intramuscular, intravenous and subcutaneous )

liquid drug formulations injected through a hollow needle using a syringe they also include implants ( must be sterile )

intravenous = large proximal vein, rapid and predictable response

intramuscular=into the muscle, small volume of injection rapid absorption, used for controlled release of formulations e.g. vaccines

subcutaneous= into subcutaneous tissue slower onset of action used for insulin and proteins

what are topical dosage forms

the application of medicines to the skin/ directly applying API to an infected area

creams- semi solid emulsions either oil in water or water in oil , oil in water is more comfortable and less greasy and easier to wash off, water in oils more difficult to handle but tend to release API more readily also more moisturizing e.g sudocream

ointments- viscous, semi soild, greasy applied to the skin, rectum and nasal mucosa

gels- clear non greasy water based semi-solids used for medication and lubrication

What are transdermal dosage forms?

drug delivery across the skin barrier e.g. patches

they deliver drugs steadily over hours or days over a fixed rate

minimises side effects

improved patient compliance, easy to use and non invasive

avoids interactions with GI tract so reduces irritation

drug delivery can be stopped by removing the patch

explain inhaled dosage forms

administration of a formulation by inhalation via the nose or mouth for pulmonary drug delivery ( delivers to lungs )

the drug is formulated as a solution or suspension or powder

the drug particles need to be very small to enter deep into the lungs

e.g. pMDI -> DPI -> nebulizer

explain rectal and vaginal dosage forms

solid dosage forms that melt, soften or dissolve into the body cavity

can be used for sustained and controlled delivery

what are excipients

all of the ingredients in a formulation other than the API

explain the features of an excipient

chemically active in the formulation- interact with other excipients or the environment

biologically active-penetration enhances in transdermal system or mucoadhesive agents

functional agents-serve a protective role e.g. preservatives antioxidants

what are advanced drug delivery forms

Advanced drug delivery forms refer to sophisticated systems that control, modify, or target the release of therapeutic agents in the body to achieve improved efficacy and reduced toxicity

give examples of advanced delivery forms

nanoparticles

microneedles

microchips