Pharmaceutical analysis

Pharmaceutical analysis is a branch of practical chemistry that involves a series of process for identification, determination, quantification and purification of a substance, separation of the components of a solution or mixture, or determination of structure of chemical compounds.

 

The substance may be a single compound or a mixture of compounds and it may be in any of the dosage form. 

The substance used as pharmaceuticals are animals, plants, microorganisms, minerals and various synthetic products.

 

The different pharmaceutical agents are as follows:

 

1.         Plants

 

2.         Microorganisms

 

3.         Minerals

 

4.         Synthetic compounds

 

Pharmaceutical analysis is traditionally defined as analytical chemistry dealing with drugs both as bulk drug substances and as pharmaceutical products (formulations). 

However, in academia, as well as in the Pharmaceutical Industry. other  branches of analytical chemistry are  also  involved,  viz.  bioanalytical  chemistry,  drug metabolism studies  and  analytical biotechnology.  

The development of drugs  in the pharmaceutical industry is  a long-term process, often taking more than a decade from the start of a research project to the appearance of a drug on the market. 

That process involves several decision points, such as the choice of the candidate drug after the preclinical screening phase, the investigational new drug (IND) application before testing the compound for the first time in man, and finally the new drug application (NDA) which summarizes the data obtained from all the studies needed for marketing approval of the drug as a medicine. 

In all these steps, especially the IND and NDA, the amount of data generated is enormous. 

Analytical chemists take part in many of the studies that constitute this documentation. 

Substance quality and its specifications are based on substance analysis, and that knowledge is later used for quality control during full-scale production. 

Product analysis involves dealing with the various formulations and starts after the IND has been approved. 

The results from such work lead to specifications that form the basis for the quality control of the product. 

For both substances and formulations there is an increasing interest in the introduction of process analytical chemistry.

 

The sample to be analysed is called as analyse.

 

    Quality control and quality assurance

    Chromatographic techniques

    Quantitative and qualitative analysis

    Validation methods

    Stoichiometry between reactants & products

Scope of Pharmaceutical Analysis

Pharmaceutical Analysis is one of the most sort after specializations in masters of pharmacy.

People specialised  in  pharmaceutical  analysis  are  indispensable to  the manufacturing, quality control and analytical manifestations of the industry.

They can work in quality control department which oversees the purity, qualitative aspects and the matching of the stringent regulatory limits required by a finished product.

Research and development has huge implications on the results of the analysis and detection of new compounds. More and more companies are stressing on a separate analytical R&D department.

Pharmaceutical analysis students also find takers in the medical devices companies, equipment companies, regulatory agencies etc.

Always remember, no matter what compounds you discover or formulation you make nothing is valid until it is evaluated, analysed and validated.

Based upon the determination type, there are mainly two types of analytical methods.

 They are as follows:

Qualitative analysis:

 

Quantitative analysis:

 

1. Qualitative analysis

This method is used for the identification of the chemical compounds. Qualitative analysis is performed to establish composition of natural/synthetic substances. These tests are performed to indicate whether the substance or compound is present in the sample or not.

 

2. Quantitative analysis

This method is used for the determination of the amount of the sample. Quantitative analytical techniques are mainly used to quantify any compound or substance in the sample. There are various methods to find out the quantity of a substance in a product.

 

Various types of Qualitative analysis:

1.Chemical methods

a) volumetric or titrimetric methods 

b) gravimetric methods

c) gasometric analysis

2.Electrical methods

3.Instrumental methods

4.Biological and microbiological

Methods of Expressing Concentration of Solution

 

Concentration of solution is the amount of solute dissolved in a known amount of the solvent or solution. The concentration of solution can be expressed in various ways as discussed below,

 

(1) Percentage: It refers to the amount of the solute per 100 parts of the solution. It can also be called as parts per hundred (pph). It can be expressed by any of following four methods,

 

(i)Weight to weight percent

% w/w =       Wt of solute   x 100

 

Wt of solution

(ii) Weight to volume percent

% w/v =       Wt of solute  x 100

 

Volume of solution

(iii) Volume to volume percent

% v/v=       Volume of solute   x 100

Volume of solution

(iv)Volume to weight percent

 

% v/w =       Volume of solute   x 100

                        Wt of solution

 

(2) Parts per million (ppm) and parts per billion (ppb):

 

When a solute is present in trace quantities, it is convenient to express the concentration in parts per million and parts per billion. It is the number of parts of solute per million (101) or per billion (109) parts of the solution. It is independent of the temperature.

Ppm=     mass of solute component   x 10

                    Total mass of solution

                                                                      9

Ppb=     mass of solute component   x 10

               Total mass of solution

 

(3) Normality (N)

 

It is defined as the number of gram equivalents (equivalent weight in grams) of a solute present per litre of the solution. Unit of normality is gram equivalents litre–1. Normality changes with temperature since it involves volume. When a solution is diluted  times, its normality also decreases by  times. Solutions in term of normality generally expressed as,

 

N= Normal solution; 5N= Penta normal,

10N= Deca normal;N/2= semi normal N/10= Deci normal; N/5= Penti normal N/100 or 0.01N= centinormal,

N/1000 or 0.001= millinormal

 

Mathematically normality can be calculated by following formula

 

Normality (N) =     Number of gm eq. of solute

 

Volume of solution (l)

(* 1 equivalent = 1000 mill equivalent or meq.)

 

(4) Molarity

 

The number of moles of solute per litter of solution OR the molar concentration of a solution usually expressed as the number of moles of solute per liter of solution.

 

It is also known as molar concentration, is the number of moles of a substance per litter of solution. Solutions libelled with the molar concentration are denoted with a capital M. A 1.0

M solution contains 1 mole of solute per litter of solution.

 

Molarity (M) =    Mole of solute

 

       Litres of solution

 

Molarity - M → moles per litter solution

 

(5) Molality

The number of moles of solute per kilogram of solvent. It is important the mass of solvent is used  and  not  the  mass  of  the  solution.  Solutions  labelled  with  molal  concentration  are denoted with a lower case m. A 1.0 m solution contains 1 mole of solute per kilogram of solvent.

 

Molality (m) =    Mole of solute  Kg of solvent

Molality - m → moles per kilogram solvent