Physical forms or states
Drugs are prepared and given in different physical forms
or states called dosage forms. A dosage form is the physical
form in which a drug is produced and given to patients. The physical form
determines how the drug is administered, absorbed, and acts inside the
body. Each form has its own importance, depending on the nature of the
drug and the condition of the patient.
1. Solid Dosage Forms
These are dry and compact forms of medicine. Examples
include tablets, capsules, powders, granules, and lozenges.
Importance:
- They
are easy to handle, transport, and store.
- Provide
accurate dosing.
- Offer good
stability and long shelf life.
- Some
solids are modified-release, giving a controlled drug release
over time.
- Convenient
for patients for self-administration.
2. Semi-Solid Dosage Forms
These are soft and smooth forms that can be applied to the skin,
eyes, or mucous membranes. Examples include ointments, creams, gels, and
pastes.
Importance:
- Used
mainly for local action on skin or mucous surfaces.
- Allow direct
application to the affected area.
- Help
in protecting, soothing, or healing the skin.
- Some
semi-solids can deliver the drug into deeper tissues for local or
systemic effect.
3. Liquid Dosage Forms
These are in liquid state and can be taken orally,
injected, or applied externally. Examples include solutions, suspensions,
syrups, elixirs, and emulsions.
Importance:
- Suitable
for children and elderly who cannot swallow solids.
- Provide
quick absorption and fast onset of action.
- Easy
to adjust the dose.
- Allow
drugs to be evenly distributed in the liquid medium.
4. Gaseous Dosage Forms
These include aerosols, inhalers, and gases used for respiratory
therapy or anesthesia.
Importance:
- Provide
rapid drug action through the lungs.
- Used
for asthma, COPD, and anesthesia.
- Require
small doses for strong and quick effects.
- Avoid first-pass
metabolism, improving efficiency
