PHARMACEUTICAL INORGANIC CHEMISTRY

1. PHARMACEUTICAL
INORGANIC CHEMISTRY
MODULE CODE :PST 04210
MODULE CREDIT 12
PREPARED BY : PHILIPO RAPHAEL

2. ACIDS AND THEIR PHARMACEUTICAL
IMPORTANCE
LEARNING OBJECTIVES
 Definition of acid
 Classification of acids
 Distinctive properties of acids
 Description of general properties of acids
 Pharmaceutical uses of acid

3. DEFINITION
 Arrhenius definition for acids
A substance that produce H+ only as a positively charged ion under
aqueous environment e.g HCl ,H2SO4
 Lewis definition of acid
Any species capable of accepting a pair of electrons (electron
acceptor) e.g. BF3
 Brønsted -Lowry definition of Acid
Brønsted acid can donate a proton and a Brønsted base can accept a
proton. For every Brønsted acid, there exists a conjugate Brønsted
base and vice versa

4. BRǾNSTED-LOWRY CLASSIFICATION

5. CLASSIFICATIONS OF ACIDS
 Strong acid
Is the acid that fully dissociates into its ions under aqueous
environment
e.g HCl ,HNo3
 Weak acid
Is the acid that partially dissociates under aqueous environment
e.g CH3COOH
NB:At the same concentration weak acid have a higher pH value than
Strong acid

6. PHYSICAL PROPERTIES OF ACIDS
 Sour taste
 Aqueous solutions of all Arrhenius acids contain hydrogen ions
 pH less than 7
 Turns phenolphthalein COLOURLESS and litmus RED
 Corrosive in nature
 Under aqueous environment they are electric conductors

7. CHEMICAL PROPERTIES OF ACIDS
 Metals above copper in the reactivity series react with acids, giving
off hydrogen gas and form a salt
 Reacts with bases to form salts (neutralization reaction)
 Reacts with metal carbonates to produce salt, water and carbon
dioxide gas (effervescence)

8. REACTIVITY SERIES

9. NEUTRALIZATION REACTION

10. EFFEVERSENCE

11. PHARMACEUTICAL USES OF ACIDS
 Analgesic preparations
e.g Acetyl salicylic acid
 Solubilizing agents
e.g Cetirizine hydrochloride ,oxycodone hydrochloride, metformin
hydrochloride , tramadol hydrochloride ,valacyclovir hydrochloride
,loperamide hydrochloride ,chlorpromazine hydrochloride
 Development of controlled release dosage forms
by improving stability through targeted drug delivery in the GIT
and extended patent life

12. PHARMACEUTICAL USES OF ACIDS
 Topical keratolytic preparations
e.g Salicylic acid
 Analytical studies
Ionization properties of the drug (pKa)
 Buffering agent (to maintain pH changes )
 Preparation of effervescent tablets
 Preparation of disinfectants
e.g. Sodium hypochlorite

13. QUOTE OF THE DAY

14. END OF SESSION
BEST REGARDS