Industrial Processing and Basic Principles – Pharmaceutical Engineering B. Pharm Third Semester PDF Notes

Industrial Processing and Basic Principles

Learning objectives

At the end of this lecture student will be able to:

• Outline the industrial applications of pharmaceutical
engineering

• Explain the difference between unit operation and unit
process

• List the unit operations with pharmaceutical applications

• Describe the concept of material and energy balances

• Explain the basic laws involved in stoichiometry

Industrial Processing and Basic Principles

Engineering

Engineering is the application of scientific knowledge in
order to invent, design, build, maintain, research and improve structures, machines, device systems, materials and processes

Pharmaceutical Engineering

It is a branch of pharmaceutical sciences and technology
that involves development and manufacture of product, processes and component in pharmaceutical industry

Pharmaceutical engineering is concerned with the study of
industrial processes in which raw materials are changed or separated into pharmaceutically useful products (drugs and excipients)

Raw materials ——> Value added products

Pharmaceutical engineering is also the study of chemical
engineering principles with special relevance to pharmacy

Objective:

Developing an approach of chemical engineering to the field
of bulk drug manufacturing and pharmaceutical processing

Applications of Pharmaceutical Engineering

Production of dosage forms

Conversion of drugs into dosage forms Ex:   Diclofenac sodium – tablets, capsule, gel, solution

Production of bulk drugs

Ex: Salicylic acid is acetylated to aspirin

Production of antibiotics

Fermentation technology Using microbes with the aid of precursor
Ex: penicillin G using Penicillium Chrysogenum along with phenyl acetic acid

Extraction of Drug

Production of biologicals from animal, plants, minerals and
native raw materials into purified product

Ex: Vaccine, DNA recombinant technology product, insulin

Unit operations

A physical or chemical process frequently consists of a
fewer number of distinct individual steps and each step is called as unit operation.

Each unit operation follows its own scientific principle.

Drying

Filtration

Size reduction

Distillation

Size separation

Evaporation

Normally every process involves a series of steps which are
performed individually as it is an economical way of organizing a process

Unit process

It is the one in which several unit operations are combined
in a sequence to achieve the objectives of a chemical or physical process.

• Unit process – Physical process: manufacture of common
salt

Transportation of fluids and solids > Transfer of heat
> Evaporation > Crystallization > Filtration > Drying >
Screening

• Unit process – Chemical process: sequence of reactions for
the production of paracetamol

                 Nitration                   Reduction Al/ H2SO4 10 h            Acetylation

Benzene————-Nitrobenzene———————P-Aminophenol———————Paracetamol


      HNO3 / H2SO4, 1 h                                                  Acetic anhydride / sulphuric acid

In the previous process, three unit processes are involved:
nitration, reduction and acetylation.

Each unit process in turn contains number of unit
operations. Ex: Nitration of benzene to nitrobenzene

1. Fluid flow: Charging of nitric acid into the reactor

2. Heat transfer: Cold brine is passed to reduce the
temperature to 150 C

3. Fluid flow: Addition of sulphuric acid

4. Fluid flow: Addition of benzene in small quantities

5. Heat transfer: Heating to 600 C for 1 hour

6. Filtration

7. Drying

8. Crystallization

Several steps are carried in a sequence in order to achieve
a process efficiently and economically

Basic laws

The general law of conservation can be applied to any
process in the form of material balance and energy balance

Material balance

The law of conservation of matter states that material
cannot be destroyed or created, it can be changed from one form to another.

The given input must be accounted for an output.

It can be applied to an equipment, or to the process or any
part of it.

INPUT
L OUTPUT

Amount of raw materials =     Amount of changed materials + Amount of unchanged materials

Exception: Radioactive process

Estimation of material balance

Normally the amount is expressed in concentration units;
Moles/ltr, Molal unit, %w/w, %w/v

 Advantages

   Provide information on yield value and percent recovery

   Validation of processes and equipment (ISO)

   Assumed central place in the current industrial development

Tie Substance

The material that comes into the process in just one stream
and leaves unchanged in only one stream.

Unit operation: Evaporation, Drying                                        

Tie substance: Dissolved solid, Bone dry material

Energy balance

• The first law of thermodynamics is a statement of
conservation of energy

• Energy cannot be created or destroyed, though energy can
be transported from one kind to another

• The law of conservation of energy states that the energy
output must be same as the energy input in a chemical process

   It includes all forms of energies (heat, mechanical, electrical, chemical, radiation)

• When one kind of energy is destroyed or consumed, an equal amount of another kind must be formed

Applications

   In the study of fluid flow

   Working of a pump

   Energy losses due to friction can be accounted

   Balancing of energy from a nonrenewable sources (efficiency and economy are important parameters)

Stoichiometry

   It means carrying out of calculations based on quantitative relationship

Stoichiometric calculations

   The numerical problems involving the use of stoichiometric equations

   A chemical reaction is a symbolic representation of a chemical change

Reactants ——–> products

Skeletal equation

H2 + O2 ——–> H2O

Balanced equation

2H2 + O2 ——–> 2H2O

The coefficients 2, 1 and 2 in equation are called
stoichiometric coefficients

• A balanced chemical equation indicates the exact number of various elements participating in the reaction

Applications

• Help in understanding the quantitative relationship
between different reactants

• Determination of the amount of reactants to be added for
carrying out a reaction

Scale of operations

The scale of a chemical process refers to the rough ranges
in mass or volume  of a chemical reaction or process that define the appropriate category of chemical apparatus and equipment required to accomplish it, and the concepts, priorities, and economies that operate at each

   Practically speaking, the scale of chemical operations also relates to the training required to carry them out, and can be broken out roughly as follows:

• Procedures performed at the laboratory scale, which involve the sorts of procedures used in academic teaching and research laboratories in the training of chemists and in
discovery chemistry venues in industry

   A pilot plant is a small industrial system which is operated to generate information about the behavior of the system for use in design of larger facilities.

• Pilot plant is a relative term in the sense that plants are typically smaller than full-scale production plants, but are built in a range of sizes.

• operations at the pilot plant scale, e.g., carried out by process chemists, which, though at the lowest extreme of manufacturing operations, are on the order of 200- to 1000-
fold larger than laboratory scale, and used to generate information on the behavior of each chemical step in the
process that might be useful to design the actual chemical production facility

• Some pilot plants are built in laboratories using stock
lab equipment, while others are constructed of fabricated metal on dedicated concrete slabs and cost millions of dollars. They can also be used to train personnel for a full-scale plant

• Pilot  plants  are used  to  reduce the  risk  associated with  construction  of large  process  plants Intermediate bench scale sets of procedures, 10- to 200-fold larger than the discovery laboratory, sometimes inserted between the preceding two

• Operations at the pilot plant scale, e.g., carried out by
process chemists, which, though at the lowest extreme of manufacturing operations, are on the order of 200- to 1000- fold larger than laboratory scale, and used to generate information on the behavior of each chemical step
in the   process that might be useful to design the actual chemical production facility

• Some pilot plants are built in laboratories using stock
lab equipment, while others are constructed of fabricated metal on dedicated concrete slabs and cost millions of dollars. They can also be used to train personnel for a full-scale plant

• Pilot plants are used to reduce the risk associated with
construction of large process plants Intermediate bench scale sets of procedures, 10- to 200-fold larger than the discovery laboratory, sometimes inserted between the preceding two

• Operations  at  demonstration scale,  full-scale production,  industrial  scale; whose  sizes  are determined by the nature of  the chemical product, available chemical technologies, the market for the product, and manufacturing requirements, where the aim of the first of these is literally to demonstrate operational stability of developed manufacturing procedures over extended periods (by operating the suite of manufacturing equipment at the feed rates anticipated for commercial production)

• For instance, the production of the streptomycin-class of
antibiotics, which combined bio-technologic and chemical   operations, involved use of a 130,000 liter fermenter, an operational scale approximately one million-fold larger than the microbial shake flasks used in the early laboratory scale studies

   Nomenclature can vary between manufacturing sectors; some industries use the scale terms pilot plant and demonstration plant interchangeably

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