Drug discovery

Introduction:
Drug discovery is the research process of designing and discovering a new drug for the required biological responses in animals resulting in desired effects in human beings. The process of drug discovery is done in different fields like Pharmacology, Biotechnology and medicine.

In old times, drug was discovered either
1. checking the ingredients from conventional or known remedies or
2. by accidental discoveries

But now study is done even the minutest molecular and physiological level so that the better drugs, targeting the specific receptors, are developed. Drug discovery is one the most lengthy and expensive processes in Pharmaceutical and related fields. One of the most important process for Drug discovery is High-Throughput screening.

Stages for an approved new molecular entity:
A new molecular entity passes through the following stages:
1. Drug Discovery
    a. Identification
    b. Synthesis
    c. Characterization
    d. Screening
    e. Assays for therapeutic effectiveness
2. Drug Development or Preclinical Development
3. Clinical Trials
    a. Phase 0
    b. Phase 1
    c. Phase 2
    d. Phase 3
    e. Phase 4

Challenges to Overcome in Drug Discovery:

Following changes are usually considered in Drug Discovery:
1. Effective targeting of the drug
2. Drug must be cost effective
3. Patient Compliance
4. Prevention of drug from degradation
5. Extended life of the drug product

Drawbacks in Drug Discovery and its removal:
This process is
- lengthy,
- difficult,
- expensive and
- Inefficient having low rate of new drug discovery.

Nowadays, the knowledge of human genome has very benefacial effects on the drug discovery as it has removed many steps of drug discovery including the study of new drug targets.

Liposome

Introduction:
Liposome is the type of extremely small artificial sacks made up of lipid monolayers or the layers can be more than one.

The outer layers are very reactive chemically and helps in the coupling of antigens, nucleic acid probes, cell recpetors and antibodies.

Size:
Liposomes may range from 50 nm to 800 nm.

Statistical Quality Control in Pharmaceutics

Definition:

Statistical quality control (SQC)is defined as:
“The monitoring of quality by application of statistical method in all stages of production.”

Explanation:
Statistical methods of investigation are based on the theory of probability.

It relates to the characteristic of product from both qualitative and quantitative point of views to meet the established standards.

Uses:

It has been used to serve:

• As a basis for improved evaluation of materials through more representative sampling technique

• As a means of achieving sharper control in certain manufacturing processes

• To provide logical approach to variations

Selection:

Selection of appropriate method depends on:
• Type of measurement
• Sampling techniques
• Design of Experiments
• Type of Sample distribution

Procedure:

The procedure consists of:

• Proper sampling of product
• Determining quality variations of the sample
• Making inferences to the entire batch under investigation from the observed data
• Once the characteristic data pattern of a process has been determined, the pattern can be utilized to predict the limits within which future data can be expected to fall as a matter of chance, and to determine when significant variations in the process have taken place.

Data Analysis:
Data can be analyzed by using appropriate method of analysis:

t-test:
t-test for comparison of two populations. T-value is calculated and from t-value the P-value is noted from the table:

If
P>0.05; test is non-significant

And if
P<0.05; test is significant.

ANOVA:
It means analysis of variance and is used for comparison of more than 2 parameters.

Objectives:
The objective is to determine whether the major source of observed variations is by chance or assignable.

Types of variations:

Chance variations:
These variations are inevitable because any program of production and inspection has its own unique chance causes of variations which can not be controlled or eliminated and often cannot be identified.

Assignable variations:
These variations can usually be detected and corrected by statistical techniques. Assignable variations are usually caused by machine or a specific batch of production or a container.

Thus the use of SQC permits the:
• Evaluation of magnitude of chance variation of product quality.
• Detection of assignable variations of product quality by means of QC charts.

Evolutionary operations in Optimization

Evolutionary operations is also referred to "EVOP" and is well suited for the production side of the industry.

In this prcoess, constant repetition and careful planning of the production process such as formulation is used to move towards better processes.

Industrial Pharmacy

Multiple Choice Questions (MCQs) from Industrial Pharmacy

1. Industrial pharmacy is basically concerned with………

a. Dispensing of medicines
b. Storage of medicines
c. Preparation of medicines
d. All of above
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2. To develop new drugs into effective medicines is the aim of ………

a. Retail pharmacy
b. Industrial pharmacy
c. Forensic pharmacy
d. Hospital pharmacy
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3. Basic facilities for pharmaceutical industry are………

a. Water
b. Light
c. Gas
d. Labour
e. All of above
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4. The proper site for pharmaceutical industry………

a. Should not be near a chemical industry
b. Must be near the city
c. Should be near a chemical industry
d. All are correct except “c”
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5. Which one of the following is the advantage of industrial pharmacy……

a) Extemporaneous preparations
b) Bulk compounding
c) Quality assurance
d) All of above
e) b and c are correct
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Answers of Multiple Choice Questions (MCQs) from Industrial Pharmacy

1. Answer is “c” that is “Preparation of medicines”

2. Answer is “b” that is “Industrial pharmacy”

3. Answer is “e” that is “All of above”

4. Answer is “d” that is “All are correct except c”

5. Answer is “e” that is “b and c are correct”

(These MCQs are helpful for the preparation of Pharmacy Exams)

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Further Reading:

The theory and practice of industrial pharmacy,

Industrial Pharmacy

Pharmaceutical Manufacturing Handbook: Production and Processes (Pharmaceutical Development Series)

Remington: The Science and Practice of Pharmacy (Remington the Science and Practice of Pharmacy)

Ansel's Pharmaceutical Dosage Forms and Drug Delivery Systems

Vesicles

Introduction:
Small packets or bubbles that are used for the transport of materials within a cell and across the cell membrane.

Classification of Vesicles:
We can classify the vesicles on the following factors:
1. Structure
2. Liposomal preparation
1. Classification on the basis of structure
There are following types of vesicles on the basis of structure:

a. Small unilamellar vesicles; abbreviated as SUV. Size ranges from 20-100 nanometer.
b. Medium sized unilamellar vesicles; abbreviated as MUV.
c. Large unilamellar vesicles; abbreviated as LUV. Size is greater than 100 nanometer.
d. Oligolamellar vesicles; abbreviated as OLV. Size ranges from 0.1-1 micrometer.
e. Multilamellar large vesicles; abbreviated as MLV. Size is greater than 0.5 micrometer.
f. Giant unilamellar vesicles; abbreviated as GUV. Size is greater than 1 micrometer.
g. Unilamellar vesicles; abbreviated as UV. All size range.
h. Multivesicular vesicles; abbreviated as MVV. Size is large, usually greater than 1 micrometer.

2. Classification on the basis of liposomal preparations

There are following types of vesicles on the basis of liposomal preparations:
 a. Vesicles made by reverse phase evaporation method:
      i. Oligolamellar vesicles (also known as single vesicles); abbreviated as REV
      ii. Multilamellar vesicles ; abbreviated as MLV-REV
 b. Stable plurilamellar vesicles; SPLV
 c. Vesicles prepared by extrusion methods; abbreviated as VET
 d. Frozen and thawed multilamellar vesicles; abbreviated as FATMLV

 e. Dehydration-rehydration vesicles; abbreviated as DRV

Time and Motion Study

Study on the efforts which utilize minimum effective time for a particular task. And how to use time effectively for doing work and undoing unnecessary activities. It is particularly use in Business efficiency for the good results.

For example in a study, reserchers (Abraham B. Bergman M.D. et al.) study how a paediatrician spend his time and work during practice.

(J. S. MCDONALD et al.) Through time and motion study, researchers have found that anaesthetist's can increase their working efficiency by sensible use of the personnel, machines or both. And by reducing their attention to unused tasks.

References:
Abraham B. Bergman M.D., Steven W. Dassel M.D. and Ralph J. Wedgwood M.D. TIME-MOTION STUDY OF PRACTICING PEDIATRICIANS , PEDIATRICS, Vol. 38 No. 2 August 1966, Pages 254-263.

J. S. MCDONALD, M.D. and R. R. DZWONCZYK, M.S.B.M.S.E., A TIME AND MOTION STUDY OF THE ANAESTHETIST'S INTRAOPERATIVE TIME. British Journal of Anaesthesia, 1988, Vol. 61, No. 6, Pages 738-742.

Further Reading:
MOTION AND TIME STUDY :PRINCIPLES AND PRACTICE , THIRD EDITION SECOND PRINTING 1961 by Marvin E. Mundel

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