Group A
In corona season
: 14
: Chandrasiri DDLS
: School of Pharmacy, NIHS
2005 Pharmaceutics II Q3
• 3.1 Explain the difference between 'dose' and 'dosage form' using
appropriate examples.
• 3.2 Briefly explain the need for three dosage forms of paracetamol;
tablets, chewable tablets and drops.
2005 Pharmaceutics II Q3 cont...
• 3.3 A batch of betamethasone sodium phosphate (M=516.4) tablet
contain 500mcg of betamethasone (M=392.5) per tablet each
weighing 120mg. With respect to this statement on the
tablets explain,
• (a) Gross weight
• (b) Active ingredient and
• (c )Active moiety
3.1 Explain the difference between 'dose' and
'dosage form' using appropriate examples.
Dose
Dosage Forms
Dose is, a predetermined amount of a
drug given at one time to induce a
certain biological response in a patient.
Or,
Dosage Form(DF) is the physical form in
which a precise mixture of Active
ingredient(API) and Excipients are
presented to help easy administration,
deliver to sites of action, achive rapid
onset of action, and improve
bioavailability. Or
Dose is, The exact amount of medication DF is the physical appearance of the
to be taken at one time.
finished drug product.
The facts here are brief. These can be further explained.
Dose
Dosage Form
Quantitative value
Not Quantitative value.
It’s on physical appearance.
Quantitative value of a drug is identified
in the clinical trials, in phase 0(preclinical
phase) and phase 1.
Sometimes later adjusts to different
dose values, according to the need.
Eg: Salbutamol 2mg tablets & 4mg
tablets.
Most often the starting DF is IV type.
In phase 1, check the best way to
administrate with various DFs.
According to the needs, different DFs are
created later.
Eg: the paracetamol was later made
into syrup because of a need.
Dose of a drug depend on its inherent
potency.
DF is depend on mainly Bioavailability
and needs.
Eg: Amoxicilline starting dose- 250mg to Eg: Salbutamol DFs- Tablets, Powders,
500mg
Injection, Respiratory solution
Severe cases- 500mg to 1g
The facts here are brief. These can be further explained.
3.2 Briefly explain the need for three dosage forms
of paracetamol; tablets, chewable tablets and
drops.
• Tablets may be defined as the solid unit dosage form of medicament
or medicaments with suitable excipients. (simply)
• The need to make the paracetamol as tablets.
• To manufacture paracetamol drug relatively easily.
• Need to make the product profitably.
• To administrate the drug without any practice or/and without
any assistance.
• To achieve prolonged stability.
• To protect from environmental conditions.
• Because it is more easily administrate via the oral route than other routes.
The facts here are brief. These can be further explained.
• Chewable tablets may be defined as tablets that are redesigned to be
processed by chewing to facilitate release of the active ingredient(s)
(simply)
• The need to make the paracetamol as chewable tablets.
• The need for a Dosage form that can be administered even when there is no
water.
• To increase the patient compliance for bitter paracetamol drug.
• Reducing the reluctance of children to take paracetamol in some cases.
• To increase the Bioavailability and Absorption of this drug in oral dosage
form.
• For those who have difficulty swallowing large tablets, for ease of
taking the paracetamol.
• For a dosage form that can be used as a more stable substitute for
liquid dosage form,
The facts here are brief. These can be further explained.
• Oral Drop is an oral liquid that is prepared to take in small quantity
with the help of a suitable measuring device such as a dropper.
(simply)
• The need to make the paracetamol as Drops.
•
•
•
•
To the convenience of giving medicines to infants.
Due to the need to separate and use in small quantities.
To accurately obtain the required small volume.
To get relatively rapid action in infants.
The facts here are brief. These can be further explained.
3.3 A batch of betamethasone sodium phosphate
(M=516.4) tablet contain 500mcg of
betamethasone (M=392.5) per tablet
each weighing 120mg. With respect to this
statement on the tablets explain,
•
•
•
(a) Gross weight
(b) Active ingredient and
(c )Active moiety
(a) Gross Weight
• The Gross weight, simply means the total weight of a load.
• In industry, gross weight include the weight of the actual product and
the packages used in wrapping it.
(Gross weight of
Betamethasone
batch)
=
(Total weight of
Betamethasone
tablets in the batch)
+
(Total weight of
Wrapping
materials)
• According to the above statement, considering only tablets, the gross
weight of a betamethasone sodium phosphate tablet is 120mg and
gross weight/Total weight of entire batch should be approximately
multiples of 120mg (n*120mg).
• In pharmaceutical industry, most of batches are released form the
company with Quaternary package. So the total weight of wrapped
materials contain the mass of all primary, secondary, tertiary and
quaternary packages.
• The equation can be modified;
(Gross weight of
Betamethasone
batch)
=
(n*120mg)
+
(all mass of (primary+
Secondary+ tertiary+
quaternary) packages)
• Advantages
• By calculating the gross weight, being able to select the right vehicle for
transport.
• In cases of high mass, it may be advisable to use lite materials to avoid
the inconvenience.
• Disadvantages
• Overweight batch can lead to problems with transportation. (reduce physical
stability, vehicle...etc)
• Overweight, financially disadvantaged.
(b) Active ingredient
• An active ingredient(Active Pharmaceutical Ingredient/API) is any
compound of a drug product intended to furnish pharmacological
activity or other direct effect in the diagnosis, cure, mitigration,
treatment or prevention of disease or to affect the structure or any
function of the body of humans or/and animals.
• Normally drug can be devided into 2 main parts;
• Active ingredient(s)
• Inactive ingredients/Excipients
• When Consider above statement, Betamethasone Sodium Phosphate
is the API.
• According to the statement, the weight of API can be calculated;
• Amount of API is = 500*10-6 g / 392.5 gmol-1
= 1.27*10-6 mol
• Weight of API is = 1.27*10-6 mol * 516.4 gmol-1 = 657.8 µg
• API content as a percentage;
• (0.658 mg / 120 mg)*100% = 0.54%
• Rest weight is consist with excipients.
(c ) Active Moiety
• Active moiety is a molecule or ion, that resposible for the
physiological or pharmacological action, excluding those appended
portions of the molecule, that cause the drug to be an ester, salt or
other non-covalent derivative of the molecule.
• According to the above definition and above given
statement, betamethasone is the Active moiety and
Betamethasone Sodium Phosphate is the API of this tablet.
• Here, non ionic Betamethasone compound is modified to be ionic
salt. By that, the dissolution rate is increased in tha gastric juice.
• Active moiety (Betamethasone) content in each tablet is 500µg.
• The pecentage of it is;
• (0.5mg / 120 mg)*100%
= 0.42%
• Sometimes Active ingredient and active moiety are same.
Thank yoU
End of the note