What is Posology?
The word “Posology” is derived from Greek words “posos” and “logos” the meaning of “posos” is “how much” and the meaning of “logos” is “science”.
So we define posology as,
It is the branch of medical science dealing with the dose or drug quantity required to produce a pharmacological effect.
Which are the factors that may Affect Dose and Drug Action?
Following are some important factors that may affect the drug dose and its action,
- Age Of individual
- Body Weight
- Gender
- Route Of Administration
- Time Of administration
- Disease Condition
- Environmental & Emotional Factors
- Addition
- Synergism
- Antagonism
- Idiosyncrasy
What is Synergism?
When two or more drugs are given in combination in such a way,that increases drug action is known as Synergism.
What is Antagonism?
It is the phenomenon in which the effect of one drug is opposed by the other drug is known as antagonism.
Example
If we use adrenaline and acetylcholine in combination the effect is neutralized because adrenaline is a vasoconstrictor and acetylcholine is a vasodilator.
What is Idiosyncrasy?
When the same drug is given to the different patients then the same effects are not observed in all individuals.
In some patients the unusual effect is observed due to different physiology and the unusual or abnormal effects of drugs is known as idiosyncrasy.
What is Solubility?
Solubility is the process that explains how much solid is dissolved in solute and is defined as,
When a solid substance comes in contact with solvent it begins to dissolve in the solvent and after some time a stage reaches when no further solid is dissolved in the solvent. At this stage, the solution is known as a saturated solution at that specific temperature and the extent to which solid is dissolved in a solvent is known as Solubility.
What Is Solubilization?
The process in which we dissolve water-insoluble substances into the water by using surfactant is known as solubilization.
What Is Co-Solvency
The process in which the solubility of those drugs is increased which are not readily soluble in water. The poor water-soluble drugs are first dissolved in those solvents which are water-miscible and in which these drugs are readily soluble so in this way solubility of poorly water-soluble drugs is increased.
What Are Surfactants?
Surfactants are the substances or additives which lower the interfacial tension between two liquid phases and make them miscible.
Surfactant has two parts, one is polar and the other is nonpolar.
Classification Of Surfactants?
Surfactants are classified into the following three main classes,
- Anionic Surfactants
- Cationic Surfactants
- Non-Ionic Surfactant
Examples.
Examples of anionic surfactant are as follows,
- Sodium Lauryl Sulphate (SLS)
- Sodium Cetyl Sulphate
Examples of cationic surfactants are as follows,
- Benzalkonium Chloride
Examples of non-ionic surfactants are as follows,
- Tweens
- Span
Define Colloid?
Any substance which consists of particles that are larger than atoms but we are not able to see with the naked eye.
What is Micelles?
When surfactant molecules form a colloidal aggregation consisting of 50-150 molecules, it is known as micelle and the surfactant concentration at which micelles are formed is known as C.M.C or critical Micelle concentration.
Also Read
Define Preservatives
Preservatives are additives that are added to pharmaceutical formulations to protect them from microbial growth. Preservatives are added to all those preparations which are stored for a long period or in those where any excipient used may promote microbial growth.
Examples
- Benzoic Acid
- Phenol
- Benzalkonium Chloride
- Methyl Paraben
- Propylparaben
Define Flocculated and Deflocculated Suspension?
Flocculated suspensions are those suspensions in which solid particles are attached to form a weak or loose aggregate and have a high rate of sedimentation.
This loose aggregate breaks easily on shaking and redisperse.
Deflocculated Suspension
Deflocculated Suspension is the suspension in which solid particles settle down as separate entities and form strongly packed sediment and this can’t be redispersed on shaking.
What Are Cerates?
These are semisolid preparations resembling ointments and have a high amount of wax intended to apply to the skin.
The higher quantity of wax in preparation prohibits its melting when applied to the skin.
Important Measurements
Following are some common domestic measurements,
1 Drop = 0.05 ml
1 Teaspoon full = 5 ml
1 Tablespoon Full = 15 ml
1 Desert Spoon Full = 10 ml
1 Tea Cup Full = 120 ml
1 Tumbler Full = 240 ml
Classification Of Drug Compendia
The drug compendia are classified as
- Official Compendia
- Non-Official Compendia
Official Compendia
Some Official compendia are as follow
- British Pharmacopoeia
- United States Pharmacopoeia
- Indian Pharmacopoeia
- International Pharmacopoeia
Non-Official Compendia
Some are given as follow
- Remington’s Pharmaceutical Science
- Bentley’s Textbook of Pharmaceutics
Enlist Type Of Containers
Following are types of commonly used containers,
- Well Closed Containers
- Airtight Containers
- Hermetically Sealed Containers
- Light Resistant Containers
- Single-dose Containers
- Multi-dose Containers
- Aerosol Containers
Well Closed Containers
A well-closed container is the type of container which is used for the protection of pharmaceutical products from contamination caused by extraneous solids.
It also prevents the loss of potency of API and prevents product loss during the transportation of products or during their storage and handling.
Airtight Containers
Airtight containers are the type of container which are used to protect the container from atmospheric contamination of solids, liquids or vapours.
Airtight containers prevent product loss due to evaporation, efflorescence or deliquescence.
Hermetically Sealed Containers
These are the type of containers from which air or other gases are not allowed to pass.
A glass ampule sealed by the fusion method is an example of this type of container.
Also Read
Quick Review of 40 Dosage Forms
Light Resistant Containers
Some drugs are degraded by the light so the light-resistant containers are used for the protection of those drugs which are degraded by the light.
Example
- Opaque Container
- Amber colour container
Single Dose Containers
As the name indicates these are the type of containers that are designed to provide a single dose supply and then are wasted.
Example
Glass ampule
Multi-Dose Containers
As the name indicates these are the types of containers that are designed in such a way that they can easily provide multiple doses of a product without affecting the product quality.
Example
Vials for Multidose.
Aerosol containers
They are designed to deliver pressurized dosage forms known as aerosols.
Popular Posts