The document discusses posology, the study of how medicines are dosed, influenced by factors such as age, body weight, and sex. It covers pediatric dose calculations through age-based, body weight, and body surface area methods, emphasizing their varying accuracy. The conclusion highlights the importance of considering the drug and its additives in dosage forms.

1.  TOPIC :- Definition, Factors affecting posology. Pediatric
dose calculations based on age, body weight and
body surface area.
PRESENTED BY:
MD INJAMUL HOQUE
Guided by:- Dr. Deepak Gupta/MR. Hirak Seikh
SUBJECT :- PHARMACEUTICS -1

2. CONTENTS
TOPIC PAGE NO
Introduction 1
Factors affecting dose 2-4
Pediatric Dose calculation 5
Conclusion 6
Reference 7

3. INTRODUCTION
1
• Posology is the study of how
medicines are dosed. It also
depends upon various factors
including age, body weight and
body surface area.

4. 2
Factors Affecting Dose
1. Age
2. Sex
3. Body Weigh
4. Route of Administration
5.Time of Administration
6. Environmental Factors
7. Emotional factors
8. Presence of disease
9. Accumulation
10. Additive effects

5. 3
Age: Age significantly impacts drug metabolism and response.
Infants, children, and the elderly may require adjusted dosages.
Weight: Body weight is a major factor, especially in pediatric dosing.
Sex: Hormonal differences between sexes can influence drug
metabolism and sensitivity.
ROUTE OF ADMINISTRATION: Doses of drug are usually
smaller than the oral doses. Intravenous route this might enhance
the chances of drug toxicity.
TIME OF ADMINISTARTION: The presence of food in the
stomach delay the absorption of drug & rapidly absorbed from
the empty stomach.

6. 4
ENVIROMENTAL FACTORS: The personality & behavior of
a physician may influence the effect of drug especially the drugs
which are intended for use in a psychosomatic disorders.
PRESENCE OF DISEASE: Drugs like barbiturates &
chlorpromazine mat produce unusually prolonged effect in patient
havin liver cirrhosis.
ACCUMULATION : Some drugs produces the toxic effect if it
is repeatedly administered for long time e.g. digitalis, emetine,
heavy metals because these drugs excreted slowly. This occurs
due to accumulative effect of the drug
ADDITIVE EFFECT : When two or more drugs administered
together is equivalent to sum of their individual pharmacological
action, the phenomenon is called as additive effect.

7. 5
Pediatric Dose Calculations :
•Age-Based Method: This method is less accurate than the body weight or BSA
methods, but it can be used in situations where the child's weight or height is
unknown. The formula for this method is:
Pediatric dose = (Child's age in years / Standard adult age in years) x Adult dose
•Body Weight Method: This method is based on the assumption that the child's
dose should be proportional to their weight. The formula for this method is:
Pediatric dose = (Child's weight in kg / Standard adult weight in kg) x Adult dose
•Body Surface Area (BSA) Method: This method is considered more accurate than
the body weight method, as it takes into account both the child's weight and height.
The formula for BSA is:
BSA (m²) = (Weight in kg x Height in cm) / 3600

8. CONClusion
6
In conclusion it may be said that the two
components of dosage form, the drug and additives,
must be given due consideration related to the
properties of the drugs and a few important
categories of pharmaceutical additives are discussed
in the succeeding chapters

9. REFERENCE
7
 The British National Formulary (BNF)
The Physician's Desk Reference (PDR)
World Health Organization (WHO)
essential medicines list

10. THANK
YOU