Page 16 - Pharmacology Mnemonics and Short Notes

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-At acidic pH (stomach) weak acid drugs e.g. Acetyl salicylic
acid (Aspirin) become more unionized  more lipid soluble

 more absorbable, while weak basic drug e.g. amphetamine
become less unionized (ionized)  less lipid soluble  less

absorbable.
-At alkaline pH (Intestine) weak basic drugs become more
unionized, more lipid soluble and more absorbable, while
weak acidic drugs become less unionized, less lipid soluble
and less absorbable.

d. Valency
+3
+2
Ferrous (Fe ) salts are more absorbed than ferric (Fe ), so
vitamin C increases absorption of iron.
• Pharmaceutical form: Solutions are better absorbed than
suspensions, the smaller the particle size of the powder, the

more is the absorption.
e. Concentration at site of administration
2) Factors related to the Patient:

1-Route of Administration:
-Absorption from subcutaneous tissue is more rapid than
absorption from mucous membranes EXCEPT pulmonary
alveoli.
- Absorption from skeletal muscle is more rapid and complete

than from subcutaneous sites.
2-State of absorbing surface
Diarrhea markedly decrease absorption of systemically acting

drugs.
3-State of general circulation (Blood Flow)
During hypovolemic shock oral and subcutaneous rout are
ineffective and drugs should be given intravenously.

Another way to enumerate these factors is (Modified form)

Chemical properties
Contents  acid or base

Pharmacology Mnemonics and Short Notes By Muhammad Ramzan Ul Rehman