Introduction to pharmaceutical chemistry

Question 1

What is pharmaceutical chemistry?

Answer 1

It is a branch of chemistry that studies features of biological and pharmaceutical sciences. It studies the investigation, discovery, design, and preparation of biologically active compounds. Also, studies metabolism, mode of action at the molecular level, and structure-activity relationship. Pharmaceutical chem. is a combination of organic and biochemistry, computational chemistry, physical chemistry, statistics, pharmacology, pharmacognosy, molecular biology, and statistics. Development of new drugs and determining formulation to deliver bioactive compounds. It obtains information on complexities due to the presence of functional moiety and the effect of physicochemical properties on target-drug molecules termed SAR and QSAR.

Question 2

History and development of pharmaceutical chem.?

Answer 2

It is mentioned for the first time in the 19th century. She nung made the first pharmacopeia. in which he stated that chaulmoogra fruit treats diarrhea, emetine for amebiasis, and cocaine for hallucination. In the 13th-20th century we have chemical analysis techniques, pharmacology development, and synthesis of chemotherapeutic agents. Kolbe, acetic acid. Berthelot, methane. Domagk, rontosil cures gram-positive bacterial infection.

Question 3

What is a biological membrane?

Answer 3

It is a phospholipid bilayer that contains a wide variety of proteins. The surface is hydrophilic whereas the interior is hydrophobic. Hydrophilic molecules react with water and one another but hydrophobic molecules only with one another.

Question 4

Define physiochemical properties.

Answer 4

It is the ability of chemical compounds to elicit pharmaceutical/therapeutical effects influencing various physicochemical properties of chemical substances on biomolecules that they interact with. Phys. is responsible for action whereas chem. able to react extracellularly.

Question 5

What is solubility and how it can be improved? Why is it important for pharmacy?

Answer 5

It is the concentration of dissolved solute which is in equilibrium with solid solute. Depends on the nature of solute and solvent, T, p, and pH. The solubility of drug is its affinity or repulsion for either aqueous or organic solvent. Atoms and molecules are held by bond that has impact on solubility. Improved by:
1. structure modification
2. employing of surfactant
3. complexion
4. using of cosolvent
Important for pharmacy:
1. governs preparation of liquid doseg and drug must be in solution before it is absorbed by the body to produce biological action
2. must be in solution in order to react with receptor

Question 6

What is partition co-efficient? Which factors affect it?

Answer 6

It influences drug transport and distribution, how drug reaches site of action from site of applicaton. It is affected by:
1. pH
2. Co solvent
3. surfuctant
4. complexion

Question 7

How partition co-efficient can be measured?

Answer 7

We use 1-octanol as the lipid phase and phosphate buffer as an aqueous phase of pH=7.4. 1-octanol is used as lipid phase:
a. it has both polar and nonpolar regions
b. Po/w is easily measured
c. Po/w correlates with many biological properties
d. can be predicted using the computational mode

Question 8

What is the importance of partition co-efficient?

Answer 8

1. in combination with Pka to predict the distribution of drugs in a biological system
2. factors such as absorption, excretion, and penetration of CNS may be related to the log P value of the drug
3. drug should be designed with the lowest possible log P to reduce toxicity, nonspecific binding, and bioavailability

Question 9

How log P can be measured?

Answer 9

It is used as a measure of lipophilicity. It can be measured ba:
1. shake-flask method
2. chromatographic method

Question 10

What is hydrogen bonding and what type do we have?

Answer 10

Hydrogen bonding is a dipole-dipole interaction with the electron-rich atom (N, O, F) and electron-deficient atom H. It is classified into 2 types:
1. intermolecular (between two or more than two molecules of the same or different compound, increasing boiling point and molecular weight of compound)
2. intramolecular (between two atoms of the same molecule, it is known as chelation, and a decrease in boiling point happens)

Question 11

Effect of hydrogen bonding?

Answer 11

1. boiling and melting point
2. water solubility
3. strength of acids
4. spectroscopic properties
5. on surface tension and viscocosity
6. biological products
7. drug-receptor interaction