Pharmaceutical Analysis I – B. Pharma 1st Semester Notes

Scope: Pharmaceutical Analysis B. Pharma 1st Semester Notes deals with the fundamentals of analytical chemistry and principles of electrochemical analysis of drugs

Objectives: Upon completion of the course student shall be able to understand the principles of volumetric and electrochemical analysis carry out various volumetric and electrochemical titrations develop analytical skills

Course Content:

Pharmaceutical Analysis 1 – UNIT-I

(a) Pharmaceutical Analysis- Definition and scope

i) Different techniques of analysis

ii) Methods of expressing concentration

iii) Primary and secondary standards.

iv) Preparation and standardization of various molar and normal solutions- Oxalic acid, sodium hydroxide, hydrochloric acid, sodium thiosulphate, sulphuric acid, potassium permanganate, and ceric ammonium sulfate

(b)Errors: Sources of errors, types of errors, methods of minimizing errors, accuracy, precision, and significant figures

(c)Pharmacopoeia, Sources of impurities in medicinal agents, limit tests.

Pharmaceutical Analysis 1 – UNIT-II

Acid-base titration: Theories of acid-base indicators, classification of acid-base titrations, and theory involved in titrations of strong, weak, and very weak acids and bases, neutralization curves

Non-aqueous titration: Solvents, acidimetry, and alkalimetry titration and estimation of Sodium benzoate and Ephedrine HCl

Pharmaceutical Analysis 1 – UNIT-III

Precipitation titrations: Mohr’s method, Volhard’s, Modified Volhard’s, Fajans method, estimation of sodium chloride.

Complexometric titration: Classification, metal ion indicators, masking, and demasking reagents, estimation of Magnesium sulfate, and calcium gluconate.

Gravimetry: Principle and steps involved in the gravimetric analysis. Purity of the precipitate: co-precipitation and post-precipitation, Estimation of barium sulfate.

Basic Principles, methods, and Application of diazotization titration.

Pharmaceutical Analysis 1 – UNIT-IV

Redox titrations

(a) Concepts of oxidation and reduction

(b) Types of redox titrations (Principles and applications) Cerimetry,  Iodimetry, Iodometry,  Bromatometry,  Dichrometry, Titration  with potassium iodate

Pharmaceutical Analysis 1 – UNIT-V

Electrochemical methods of analysis

Conductometry- Introduction, Conductivity cell, Conductometric titrations, applications.

Potentiometry – Electrochemical cell, construction and working of reference (Standard hydrogen, silver chloride electrode, and calomel electrode) and indicator electrodes (metal electrodes and glass electrode), methods to determine the end point of potentiometric titration and applications.

Polarography – Principle, Ilkovic equation, construction and working of dropping mercury electrode and rotating platinum electrode, applications

Pharmaceutical Analysis: A Comprehensive Overview

Pharmaceutical analysis is a crucial discipline within the realm of pharmaceutical sciences. It encompasses a wide range of techniques and methodologies employed to assess the quality, purity, and potency of pharmaceutical substances and formulations. By employing various analytical tools, pharmaceutical analysts ensure that the medicines we consume are safe, effective, and meet the required standards. In this post, we will delve into the fundamental aspects of pharmaceutical analysis, exploring its definition, scope, and the different techniques utilized in this field.

Definition and Scope:
Pharmaceutical analysis refers to the scientific investigation and examination of pharmaceutical substances and products to determine their chemical composition, identity, purity, and potency. It involves a diverse range of analytical techniques, including both classical and modern methods, to assess the quality and compliance of pharmaceutical formulations. The scope of pharmaceutical analysis extends to various areas, such as drug development, manufacturing, quality control, regulatory compliance, and forensic analysis.

Errors in Pharmaceutical Analysis:
Despite the meticulousness and precision involved in pharmaceutical analysis, errors can still occur during the analytical process. These errors can be categorized into systematic errors and random errors. Systematic errors arise due to instrument calibration, improper sample preparation, or faulty methodology, leading to consistent deviations in results. On the other hand, random errors are unpredictable and can occur due to variations in measurement conditions, human factors, or other uncontrollable factors. To minimize errors, analysts employ rigorous validation protocols, quality control measures, and statistical analysis techniques.

Pharmacopoeia:
Pharmacopoeias serve as authoritative reference books that provide comprehensive information and guidelines for the quality control of pharmaceutical substances and formulations. They contain standards for drug identity, purity, strength, and other critical parameters. Pharmacopoeias, such as the United States Pharmacopeia (USP), Indian Pharmacopoeia, European Pharmacopoeia, and British Pharmacopoeia (BP), play a pivotal role in harmonizing the quality standards of pharmaceutical products worldwide, facilitating international trade and ensuring patient safety.

Analytical Techniques in Pharmaceutical Analysis:
1. Acid-Base Titration: Acid-base titration involves the determination of the concentration of an acid or a base in a solution using a standardized reagent of known concentration. This technique is widely employed in pharmaceutical analysis to assess the acid-base properties of pharmaceutical substances.

2. Non-aqueous Titration: Non-aqueous titration refers to titration methods conducted in solvents other than water. It is particularly useful when water-sensitive or poorly soluble substances need to be analyzed. Non-aqueous titrations find application in assessing pharmaceutical compounds that exhibit limited solubility in water.

3. Precipitation Titrations: Precipitation titrations involve the formation of insoluble precipitates as a result of a chemical reaction between the analyte and the titrant. These titrations are commonly used to determine the concentration of halides, sulfates, and other pharmaceutical substances that form precipitates with suitable reagents.

4. Complexometric Titration: Complexometric titration involve the formation of stable complexes between metal ions and complexing agents. This technique finds extensive use in pharmaceutical analysis for the determination of metal impurities, such as heavy metals, in drug substances and formulations.

5. Gravimetry: Gravimetric analysis involves the determination of the quantity of an analyte based on its mass or the mass of a product formed during a chemical reaction. Gravimetric techniques are utilized in pharmaceutical analysis for determining the purity of drug substances and the content uniformity of pharmaceutical formulations.

6. Redox Titrations: Redox titrations are based on oxidation-reduction reactions between the analyte and titrant. These titrations are valuable in pharmaceutical analysis for the determination of active ingredients, antioxidants, and other substances that exhibit redox properties.

7. Electrochemical Methods of Analysis: Electrochemical methods, such as voltammetry, amperometry, and potentiometry, utilize the electrical properties of substances to determine their concentration or analyze their electrochemical behavior. These techniques are employed in pharmaceutical analysis for the quantification of various pharmaceutical compounds and the evaluation of electrochemical stability.

PHARMACEUTICAL ANALYSIS (Practical)

1 Limit the Test to the following

(1) Chloride

(2) Sulphate

(3) Iron

(4) Arsenic

2 Preparation and standardization of

(1) Sodium hydroxide

(2) Sulphuric acid

(3) Sodium thiosulfate

(4) Potassium permanganate

(5) Ceric ammonium sulfate

3 Assay of the following compounds along with Standardization of Titrant

(1) Ammonium chloride by acid-base titration

(2) Ferrous sulfate by Cerimetry

(3) Copper sulfate by Iodometry

(4) Calcium gluconate by complexometry

(5) Hydrogen peroxide by Permanganometry

(6) Sodium benzoate by non-aqueous titration

(7) Sodium Chloride by precipitation titration

4 Determination of Normality by electro-analytical methods

(1) Conductometric titration of strong acid against a strong base

(2) Conductometric titration of strong acid and weak acid against a strong base

(3) Potentiometric titration of strong acid against a strong base

Pharmaceutical Analysis 1st semester -Recommended Books: (Latest Editions)

1. A.H. Beckett & J.B. Stenlake’s, Practical Pharmaceutical Chemistry Vol I & II, Stahlone Press of University of London

2. A.I. Vogel, Text Book of Quantitative Inorganic analysis

3. P. Gundu Rao, Inorganic Pharmaceutical Chemistry

4. Bentley and Driver’s Textbook of Pharmaceutical Chemistry

5. John H. Kennedy, Analytical chemistry principles

6. Indian Pharmacopoeia.