The above Presentation discusses about the chapter polymers.Its definition, Types and important applications.It also covers about the process of bio degradation of polymers in the body.
The above Presentation discusses about the chapter polymers.Its definition, Types and important applications.It also covers about the process of bio degradation of polymers in the body.
Introduction
Types of polymer
Classification of Polymer
Polymerization
Biodegradable Polymer
Application of biodegradable polymer
Natural polymer
They occur naturally and are found in plants and animals. For example, proteins, starch, cellulose, and rubber. To add up, we also have biodegradable polymers called biopolymers.
Semi-synthetic Polymers:
They are derived from naturally occurring polymers and undergo further chemical modification. For example, cellulose nitrate, and cellulose acetate.
Synthetic Polymers
These are man-made polymers. Plastic is the most common and widely used synthetic polymer. It is used in industries and various dairy products. For example, nylon-6, 6, polyether’s etc.
Thermosetting polymersThese polymers greatly improve the material’s mechanical properties. It provides enhanced chemical and heat resistance. For example, phenolics, epoxies, and silicones.Addition Polymerization: For Example, poly ethane, Teflon, Polyvinyl chloride (PVC)Condensation Polymerization: Example, Nylon -6, 6, perylene, polyesters.
Polymer - a long chain molecule made up of many small identical units of Monomer is known as Polymer.
Monomer - the smallest repeating unit is known as Monomer.
Polymer is a molecule is obtained by natural and synthetic origin having group of Smallest repeating unit is known as polymer.
Polymer is important for increasing the stability of drug molecule, it is important to influencing the solubility of drug molecule, it is important to maintain the Physicochemical properties, it is important to maintain the prolong stability of drug molecule in extended period of time, it is important for influencing the Bioavailability of drug.
Polymer is important for Pharmaceutical industries and research purpose.
Polymers Used in Pharmaceutical SciencesOyshe Ahmed
INTRODUCTION
CLASSIFICATION AND CHARACTERISTICS OF POLYMERS
MECHANISM OF DRUG RELEASE FROM POLYMER
BIO DEGRADATION OF POLYMERS
SYNTHESIS OF POLYMERS
POLYMERS USED IN FORMULATION OF DIFFERENT DRUG DELIVERY SYSTEM.
APPLICATION OF POLYMERS
POLYMERS IN SOLID STATE, PHARMACEUTICAL APPLICATIONS OF POLYMERS AND RECENT A...Priyanka Modugu
A description on polymers in solid state, solid state properties of polymers, mechanical properties of polymers, heat of crystallization & fusion, thermodynamics of fusion & crystallization, pharmaceutical applications of polymers and recent advances in the use of polymers for drug delivery system
Solutions: types and properties of solutions. Units of concentration, ideal and real
solutions. Henry’s law, distribution of solids between two immiscible liquids, distribution
law. Partition coefficient and solvent extraction.
Introduction
Types of polymer
Classification of Polymer
Polymerization
Biodegradable Polymer
Application of biodegradable polymer
Natural polymer
They occur naturally and are found in plants and animals. For example, proteins, starch, cellulose, and rubber. To add up, we also have biodegradable polymers called biopolymers.
Semi-synthetic Polymers:
They are derived from naturally occurring polymers and undergo further chemical modification. For example, cellulose nitrate, and cellulose acetate.
Synthetic Polymers
These are man-made polymers. Plastic is the most common and widely used synthetic polymer. It is used in industries and various dairy products. For example, nylon-6, 6, polyether’s etc.
Thermosetting polymersThese polymers greatly improve the material’s mechanical properties. It provides enhanced chemical and heat resistance. For example, phenolics, epoxies, and silicones.Addition Polymerization: For Example, poly ethane, Teflon, Polyvinyl chloride (PVC)Condensation Polymerization: Example, Nylon -6, 6, perylene, polyesters.
Polymer - a long chain molecule made up of many small identical units of Monomer is known as Polymer.
Monomer - the smallest repeating unit is known as Monomer.
Polymer is a molecule is obtained by natural and synthetic origin having group of Smallest repeating unit is known as polymer.
Polymer is important for increasing the stability of drug molecule, it is important to influencing the solubility of drug molecule, it is important to maintain the Physicochemical properties, it is important to maintain the prolong stability of drug molecule in extended period of time, it is important for influencing the Bioavailability of drug.
Polymer is important for Pharmaceutical industries and research purpose.
Polymers Used in Pharmaceutical SciencesOyshe Ahmed
INTRODUCTION
CLASSIFICATION AND CHARACTERISTICS OF POLYMERS
MECHANISM OF DRUG RELEASE FROM POLYMER
BIO DEGRADATION OF POLYMERS
SYNTHESIS OF POLYMERS
POLYMERS USED IN FORMULATION OF DIFFERENT DRUG DELIVERY SYSTEM.
APPLICATION OF POLYMERS
POLYMERS IN SOLID STATE, PHARMACEUTICAL APPLICATIONS OF POLYMERS AND RECENT A...Priyanka Modugu
A description on polymers in solid state, solid state properties of polymers, mechanical properties of polymers, heat of crystallization & fusion, thermodynamics of fusion & crystallization, pharmaceutical applications of polymers and recent advances in the use of polymers for drug delivery system
Solutions: types and properties of solutions. Units of concentration, ideal and real
solutions. Henry’s law, distribution of solids between two immiscible liquids, distribution
law. Partition coefficient and solvent extraction.
Polfosfazenlerin aşı formulasyonunda kullanımı ile ilgili bir yayın değerlendirilmiştir. Adjuvanlar ve onların kullanımı ile ilgili bilgiler verilmiştir.
Nanopartiküller ve immun sistem; etkileri ve güvenilirlikleriSema Arısoy
Son yıllarda etkin maddelerin yan etkilerini azaltmak ve hedeflendirme sağlamak için nanopartiküler ilaç sistemleri geliştirilmiştir. Ancak bu sistemler insan vücudunda her zaman istenen etkiyi sağlayamamaktadır. Bunun nedenlerinden biride immun sistemdir.
*CONTENT 1. INTRODUCTION 2. CLASSIFICATION 3. PROPERTIES OF POLYMERS 4. ADVANTAGES 5. APPLICATIONS
INTRODUCTION
➢ Polymers are becoming increasingly important in the field of drug
delivery. ➢ The pharmaceutical applications of polymers range from their used as
binders in tablets formulations to viscosity and flow controlling agents
in liquids, suspensions and emulsions.➢ Polymers are macromolecules with high molecular mass composed of
considerable numbers of monomers.➢ The term polymer is derived from the Greek words, poly means many
and meros means unit or parts.➢ Polymerization is the process of combining two or more monomers
under the definite condition of temperature, pressure and in the
presence of suitable catalyst.
POLYMERS
Introduction:
It is synonym for Plastic.
Also known as Macromolecules.
The word ‘polymer’ comes from Greek words: polymeros
Poly means ‘many’ and ‘mer’ means ‘parts’.
These are very large molecules consisting of many repeating units called monomers [small molecules] and are formed by a process called polymerization.
In other words, polymers are very large molecules made when 100’s of monomers join together to form long chains.
Ideal Properties:
1. It should be inert.
2. It should be non-toxic.
3. It should be compatible with environment.
4. It should be easy to fabricate and inexpensive.
5. It should be biodegradable and biocompatible.
6. It should provide good drug polymer linkage.
Classification of Polymers
1. Based on the Source of Availability
There are three types of classification under this category, namely, natural, synthetic, and semi-synthetic polymers.
a. Natural Polymers
They occur naturally and are found in plants and animals. For example, proteins, starch, cellulose and rubber. To add up, we also have biodegradable polymers called biopolymers.
b. Semi-synthetic Polymers
They are derived from naturally occurring polymers and undergo further chemical modification. For example, cellulose nitrate and cellulose acetate.
c. Synthetic Polymers
These are human-made polymers. Plastic is the most common and widely used synthetic polymer. It is used in industries and various dairy products. For example, nylon-6, 6, polyether, etc.
2. Based on the Structure of the Monomer Chain:
a. Linear Polymers
The structure of polymers containing long and straight chains falls into this category. PVC, i.e., polyvinyl chloride, is largely used for making pipes, and an electric cable is an example of a linear polymer.
b. Branched-chain Polymers
When linear chains of a polymer form branches, then such polymers are categorized as branched chain polymers. For example, low-density polythene.
c. Cross-linked Polymers
They are composed of bifunctional and trifunctional monomers. They have a stronger covalent bond in comparison to other linear polymers. Bakelite and melamine are examples of cross-linked polymers.
3. Classification Based on Polymerization
a. Addition Polymerization: For example, poly ethane, Teflon, polyvinyl chloride (PVC), etc.
b. Condensation Polymerization: Eg include nylon -6, 6, perylene, polyesters, etc.
4.Classification Based on Monomers
a. Homomer: In this type, a single type of monomer unit is present. Eg, polyethene.
b. Heteropolymer or co-polymer: It consists of different types of monomer units. Eg, nylon -6, 6.
5.Classification Based on Molecular Forces
a. Elastomers: These are rubber-like solids, and weak interaction forces are present in them. Eg, rubber.
b. Thermoplastics: These have intermediate forces of attraction. eg polyvinyl chloride.
c. Thermosetting polymers: These polymers greatly improve the material’s mechanical properties. It provides enhanced chemical and heat resistance. Eg silicones, phenolics.
Polymers are very large molecules made when hundreds of monomers join together to form long chains .
The word POLYMER comes from the Greek words poly means many and mer means parts .
Polymer is used as a synonym for plastic .
All plastics are polymers , but not all polymers are plastics
Unveil the fascinating realm of polymers with our comprehensive PowerPoint presentation. Delve into the intricate chemistry behind these versatile materials and discover their diverse range of properties and applications.
Our presentation begins with an exploration of polymer chemistry, elucidating fundamental concepts such as polymerization mechanisms and macromolecular structures. Gain insights into the synthesis methods employed to fabricate polymers with tailored properties, including addition polymerization, condensation polymerization, and more.
Moving forward, we delve into the myriad properties exhibited by polymers, spanning mechanical, thermal, electrical, and optical characteristics. Explore how polymer structure and composition influence these properties, paving the way for innovative applications in various industries.
From everyday items to cutting-edge technologies, polymers play a pivotal role in countless applications. Learn about the wide-ranging uses of polymers in sectors such as packaging, automotive, healthcare, electronics, and aerospace. Discover how advancements in polymer science continue to drive innovation and shape our modern world.
Moreover, our presentation sheds light on emerging trends in polymer research and development, including biodegradable polymers, nanocomposites, and smart polymers. Explore the sustainable aspects of polymers, such as recycling and bioplastics, as we strive towards a more environmentally conscious future.
Whether you're a student, researcher, or industry professional, this PowerPoint presentation serves as an invaluable resource for understanding the science, technology, and impact of polymers in today's society. Join us on a journey through the captivating world of polymers and unlock the boundless opportunities they present.
Polymers have played an integral role in the advancement of drug delivery technology by providing controlled release of therapeutic agents in constant doses over long periods, cyclic dosage, and tunable release of both hydrophilic and hydrophobic drugs.
Standardization of Acids and bases.
2. Determination of pKa and pKb values
3. Preparation of solutions of different pH & buffer capacities.
4. Determination of phase diagram of binary systems.
Determination of distribution coefficients.
6. Determination of molecular weight by Victor Meyer’s Method.
7. Determination of heats of solutions by measuring solubility as a function of temperature
(Van’t Hoff equation.)
A. Qualitative analysis of metal ions and acid radicals:
Na+, K+, Ca+2, Ag+, Mn+4, Fe+2, Fe+3, Co+2, Mg+2, Al+3, Cu+2 and acid radicals CO3,
halides, Citrate
SO4-2, NO3-, SO3-2, etc.
B. Identification of inorganic drugs in their formulation:
1. Ca+2, from supplied preparations
2. Fe+2 from supplied preparations
3. Al+3 from supplied preparations
4. Mg+2 from supplied preparations
5. K+ from supplied reparations
6. Na+ from supplied preparations
C. Conversion of different water insoluble or sparingly soluble drugs into water soluble
forms:
1. Na/ K – salicylate from salicylic acid
2. Na/ K – benzoate from benzoic acid
3. Na/ K – citrate from citric acid
Plants in complimentary and traditional systems of medicine MANIKanikImran Nur Manik
Plants in complimentary and traditional systems of medicine: Introduction-different types of
alternative systems of treatments (e.g. Ayurvedic, Unani and Homeopathic medicine). Contribution
of traditional drugs to modern medicines. Details of some common indigenous traditional drugs:
Punarnava, Vashaka, Anantamul, Arjuna, Chirata, Picrorhiga, Kalomegh, Amla, Asoka, Bahera,
Haritaki, Tulsi, Neem, Betel nut, Joan, Karela, Shajna, Carrot, Bael, Garlic, Jam and Madar.
Crude drugs: A general view of their origin, distributions, cultivation, collection, drying and
storage, commerce and quality control.
a) Classification of drugs.
b) Preparation of drugs for commercial market
c) Evaluation of crude drugs.
d) Drug adulteration.
Carbohydrate and related compounds: Sugars and sugar containing drugs. Sucrose,
dextrose, glucose, fructose etc. Polysaccharides and polysaccharide containing drugs,
Starches, dextrins etc. Gums and mucilages, tragacanth, acacia, sterculia, sodium
alginate, agar and cellulose.
Volatile oils and related terpenoids-Methods of obtaining volatile oils,
chemistry, their medicinal and commercial uses, biosynthesis of some important
volatile oils used as drugs.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
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Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
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Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Are There Any Natural Remedies To Treat Syphilis.pdf
Polymer Science For Pharmaceuticals-MANIK
1.
2. Md.
Imran
Nur
Manik
Md.
Imran
Nur
Manik
Polymer Science For Pharmaceuticals
Prepared By: Md. Imran Nur Manik; M.Pharm. (R.U.) Page 1
manikrupharmacy@gmail.com; Lecturer; Department of Pharmacy; Primeasia University.
Polymer Science for Pharmaceuticals
Introduction
Polymer Science or Macromolecular Science is a subfield of Materials Science. It is relatively a
new branch of science; concerned with polymers, primarily synthetic polymers such as plastics
and elastomers.
Polymer Science has been the backbone for the development of new formulations for past few
years and its advances have led to development of several applications in pharmaceutical
science.
Definition: Polymers
The term "polymer" derives from the ancient Greek word polus, meaning "many, much" and
meros, meaning "parts", and refers to a molecule whose structure is composed of multiple
repeating units.
Polymers are high molecular weight compounds or macromolecules composed of many
repeating subunits called “MONOMERS”, connected by covalent bonds or chemical bonds. The
reaction involving combination of two or more monomer units to form a long chain polymer is
termed as polymerization.
The key difference between early polymers and pharmaceutical polymers is biocompatibility.
These are widely used as Pharmaceutical aids like suspending agents, Emulsifying agents,
Adhesives, Coating agents, Adjuvants etc. Packaging material and medical devices both in
conventional and controlled drug delivery systems.
Other Definitions
A Polymer is like a thread that is joined by many coins punched through the center, in the end we get a string of
coins, the coins would be the monomers and the chain with the coins would be the polymer.
E.g. Polyethylene = Ethylene-ethylene-ethylene-ethylene-…
Polymers are long chain giant organic molecules assembled from many smaller molecules called monomers. A
polymer is analogous to a necklace made from many small beads.
Herman Staudinger, who received the Nobel Prize in Chemistry in 1953, coined the term “macromolecule” in
1922 and used it in reference to polymers. The difference between the polymers and macromolecules is that
polymers are made of repeating units, whereas the term macromolecule refers to any large molecule, not
necessarily just those made of repeating units. So, polymers are considered to be a subset of macromolecules.
A monomer is a small molecule that combines with other molecules of the same or different types to form a
polymer. If two, three, four, or five monomers are attached to each other, the product is known as a dimer, trimer,
tetramer, or pentamer, respectively. An oligomer contains from 30 to 100 monomeric units. Products containing
more than 200 monomers are simply called a polymer (Fig. 20–1). From a thermodynamic perspective, polymers
cannot exist in the gaseous state because of their high molecular weight. They exist only as liquids or high solid
materials.
3. Md.
Imran
Nur
Manik
Md.
Imran
Nur
Manik
Polymer Science For Pharmaceuticals
Prepared By: Md. Imran Nur Manik; M.Pharm. (R.U.) Page 2
manikrupharmacy@gmail.com; Lecturer; Department of Pharmacy; Primeasia University.
Classification of Polymers
A. Based on Backbone
1. Polymers with carbon chain backbone:
Polyethylene, Polypropylene, Polystyrene, Poly (vinyl chloride), Polyacrylonitrile,
Polyacrylamide, Poly (vinyl alcohol), Poly (methyl methacrylate), Poly vinylpyrrolidone
2. Polymers with heterochain backbone:
Poly (ethylene oxide), Poly (propylene oxide), cellulose (Poly-glucopse,→1.4), Amyloose
(Poly-glucoside,→1,4) {Component of starch), Pectinic acid (Polygalacvtouronoside),
Polyehylene glycolterepthalate, Polydimethylsiloxane etc.
B. Based on Occurrence
1. Natural polymers: Natural polymers are derived from natural sources and can be
polysaccharides and proteins in chemical nature.
Protein-based polymers: Collagen, albumin, gelatin
Polysaccharides: Agarose, alginate, carrageenan, hyaluronic acid, dextran, chitosan,
cyclodextrins
2. Synthetic polymers: Synthetic polymers are of artificial origin which consists of fibers
like Teflon and Dacron, Synthetic Rubbers, Plastics and PVC.
It has the following subtypes
I. Biodegradable Polymers: Biodegradable polymers are defined as polymers comprised of
monomers linked to one another through functional groups and have unstable links in the backbone.
They are broken down into biologically acceptable molecules that are metabolized and removed from
the body via normal metabolic pathways.
4. Md.
Imran
Nur
Manik
Md.
Imran
Nur
Manik
Polymer Science For Pharmaceuticals
Prepared By: Md. Imran Nur Manik; M.Pharm. (R.U.) Page 3
manikrupharmacy@gmail.com; Lecturer; Department of Pharmacy; Primeasia University.
It includes the followings
a. Natural bio-degradable polymers: These polymers are very common in nature. The use of
these polymers is limited because of their high costs and questionable purity.
Examples-Albumin, Collagen, Gelatin, Starch etc.
b. Synthetic Bio-degradable polymers:
These types of polymers are preferred rather than natural bio-degradable polymers due to their
inertness and easy and cheap formulation.
Synthetic bio-degradable polymers have following advantages over natural ones:
• Localized delivery of drug.
• Sustain delivery of drug.
• Stabilization of drug.
• Reduced side effects etc.
Examples- Poly lactide homopolymer, Polyester etc.
c. Semi-Synthetic Polymers:
These types of polymers are derived from naturally occurring polymers by means of chemical
modifications.
E.g. Vulcanized rubber, Gun cotton, Cellulose diacetate, HPMC etc.
d.Polyesters: Poly (lactic acid), poly(glycolic acid), poly(hydroxy butyrate),
poly(- caprolactone), poly(-malic acid), poly(dioxanones)
e.Polyanhydrides: Poly (sebacic acid), poly(adipic acid),poly(terphthalic acid) and various
copolymers
f.Polyamides: Poly (imino carbonates), polyamino acids
g.Phosphorous-based polymers: Polyphosphates, polyphosphonates, polyphosphazenes
h.Others: Poly (cyano acrylates), polyurethanes, polyortho esters, polydihydropyrans,
polyacetals
II. Non-biodegradable: It includes the followings
a.Cellulose derivatives: Carboxymethyl cellulose, ethyl cellulose, cellulose acetate, cellulose
acetate propionate, hydroxypropyl methyl cellulose
b.Silicones: Polydimethylsiloxane, colloidal silica
c. Acrylic polymers: Polymethacrylates, poly(methyl
methacrylate),polyhydro(ethylmethacrylate)
d.Others: Polyvinyl pyrrolidone, ethyl vinyl acetate, poloxamers, poloxamines
C. Based Upon Molecular Forces
I. Thermoplastic Polymer: Some polymer are soften on heating and can be converted into any
shape that they can retain on cooling. Such polymer that soften on heating and stiffen on cooling
are termed as `thermoplastic‟ polymers. Ex. Polyethylene, PVC, nylon, sealing wax.
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II. Thermosetting Polymer : Polymer that become an infusible and insoluble mass on heating
are called „thermosetting‟ polymers. Thermosetting polymers are cross-linked polymers, which
are formed upon combined application of a cross-linker and heat or combined application of
heat and reaction of internal functional groups.
Plastics made of these polymers cannot be stretched, are rigid and have a high melting point.
Ex. Polyurethanes, Bakelite, phenol-formaldehyde ,Melamine resin ,Epoxy resin , Polyimides
III. Elastomers: When plastics are vulcanised into rubbery products exhibiting good strength
and elongation, polymers are known as „elastomers‟. E.g. silicone rubber, natural rubber,
synthetic rubber, etc.
IV. Fibres: The polymers which are filament like materials, having their length at least 100 times
to their diameter, are said to be „fibres‟. E.g. Nylon, terylene.
D. Based on Composition:
1. Homopolymer:
Homopolymers- consist of chains with identical bonding linkages to each monomer unit. This
usually implies that the polymer is made from all identical monomer molecules.
These may be represented as : -[A-A-A-A-A-A]-
e.g. Polyethylene, polystyrene
2. Copolymer:
A polymer of two or more different monomers. The synthetic rubber used to make tire treads
and shoe soles, for example, is a copolymer made of the monomers butadiene and styrene
These may be represented as : -[A-B-A-B-A-B]-
e.g. Silicone, Ethyl cellulose
Physical, chemical and mechanical properties of Polymer
Polymer properties are broadly divided into several classes based on the scale at which the
property is defined as well as upon its physical basis. These are as follows:
1. Monomers and repeat units
2. Microstructure
2.1. Polymer architecture
2.2. Chain length
2.3. Monomer arrangement in copolymers
2.4. Tacticity
3. Polymer morphology
3.1. Crystallinity
3.2. Chain conformation
4. Mechanical properties
4.1. Tensile strength
4.2. Young's modulus of elasticity
5. Transport properties
6. Phase behavior
6.1. Melting point
6.2. Glass transition temperature
6.3. Mixing behavior
6.4. Inclusion of plasticizers
7. Chemical properties
8. Optical properties
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1. Monomers and repeat units
The first and most important attribute of the repeat units (monomer residues, also known as
"mers") comprising a polymer is its identity. Polymers that contain only a single type of repeat
unit are known as homopolymers, while polymers containing a mixture of repeat units are
known as copolymers.
For example, polynucleotides such as DNA are composed of a variety of nucleotide subunits.A polymer molecule
containing ionizable subunits is known as a polyelectrolyte or ionomer.
2. Microstructure
The microstructure of a polymer (sometimes called configuration) relates to the physical
arrangement of monomer residues along the backbone of the chain. These are the elements of
polymer structure that require the breaking of a covalent bond in order to change.
2.1. Polymer architecture
An important microstructural feature of a polymer is its architecture and shape, which relates to
the way in which the branch points lead to a deviation from a simple linear chain. A polymer's
architecture affects many of its physical properties including, solution viscosity, solubility in
various solvents, glass transition temperature and the size of individual polymer coils in
solution.
2.2. Chain length
The physical properties of a polymer are strongly dependent on the size or length of the
polymer chain. For example, as chain length is increased, melting and boiling temperatures
increase quickly. Increasing chain length furthermore tends to decrease chain mobility,
increase strength and toughness, and increase the glass transition temperature (Tg).
2.3. Monomer arrangement in copolymers
Monomers within a copolymer may be organized along the backbone in a variety of ways.
Alternating copolymers
Periodic copolymers
Statistical copolymers
Block
Graft or grafted copolymers
2.4. Tacticity
Tacticity describes the relative stereochemistry of chiral centers in neighboring structural units
within a macromolecule.
There are three types: isotactic (all substituents on the same side), atactic (random placement of substituents),
and syndiotactic (alternating placement of substituents).
3. Polymer morphologyPolymer morphology generally describes the arrangement and
microscale ordering of polymer chains in space.
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3.1. Crystallinity
Synthetic polymers may consist of both crystalline and amorphous regions; the degree of
crystallinity may be expressed in terms of a weight fraction or volume fraction of crystalline
material.
3.2. Chain conformation
The space occupied by a polymer molecule is generally expressed in terms of radius of
gyration, which is an average distance from the center of mass of the chain to the chain itself.
4. Mechanical properties
These are the properties that dictate how the polymer actually behaves on a macroscopic scale.
4.1. Tensile strength
The tensile strength is very important in applications that rely upon a polymer's physical
strength or durability.
4.2. Young's modulus of elasticity
Young's Modulus quantifies the elasticity of the polymer.
It is defined, for small strains, as the ratio of rate of change of stress to strain. Like tensile strength, this is highly
relevant in polymer applications involving the physical properties of polymers, such as rubber bands.
5. Transport properties
Transport properties are very important in many applications of polymers for films and
membranes.
6. Phase behavior
6.1. Melting point
The term melting point, when applied to polymers, suggests not a solid–liquid phase transition
but a transition from a crystalline or semi-crystalline phase to a solid amorphous phase.
6.2. Glass transition temperature
A parameter of particular interest in synthetic polymer manufacturing is the glass
transition temperature (Tg), at which amorphous polymers undergo a transition from a rubbery,
viscous liquid, to a brittle, glassy amorphous solid on cooling. The glass transition temperature
may be engineered by altering the degree of branching or crosslinking in the polymer or by
the addition of plasticizer.
6.3. Mixing behavior
In general, polymeric mixtures are far less miscible than mixtures of small molecule materials.
In dilute solution, the properties of the polymer are characterized by the interaction between
the solvent and the polymer.
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6.4. Inclusion of plasticizers
Inclusion of plasticizers tends to lower Tg and increase polymer flexibility.
7. Chemical properties
The attractive forces between polymer chains play a large part in determining polymer's
properties.
8. Optical properties
Polymers such as Poly(methyl methacrylate) ;PMMA and HEMA: MMA are used as matrices in the
gain medium of solid-state dye lasers that are also known as polymer lasers.
Characteristics of an ideal polymer
An ideal polymer should have the following properties
1. It should be versatile and possess a wide range of mechanical, physical, chemical
properties.
2. It should be non‐toxic.
3. It should have good mechanical strength.
4. It should be easily administered.
5. It should be inexpensive and easy to fabricate the dosage form.
6. It should be inert to host tissue.
7. It should be compatible with environment.
Selection Parameters for Biomedical Polymers
The design and selection of biomaterials depend on different properties –
Host Response: The response of the host organism (local and systemic) to the implanted
polymeric material or device.
Biocompatibility: The ability of a material to perform with an appropriate host response, in a
specific application.
Toxicology: Should not be toxic
Appropriate Design and Manufacturability: Biomaterials should be machinable, moldable,
extrudable.
Mechanical Properties of Biomedical polymers: Tensile strength, yield strength, elastic
modulus, surface finish, creep, and hardness.
Application of Biomedical Polymers
1. Artificial Heart.
2. Bones, Joints, and Teeth.
3. Contact Lenses and Intraocular Lenses.
4. Artificial Kidney and Hemodialysis Materials.
5. Oxygen-Transport Membranes.
6. Surgical Sutures.
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manikrupharmacy@gmail.com; Lecturer; Department of Pharmacy; Primeasia University.
POLYMERS IN PHARMACEUTICAL AND BIOMEDICAL APPLICATIONS
Water-Soluble Synthetic Polymers
Poly (acrylic acid): Immobilization of cationic drugs, base for Carbopol polymers
Poly (ethylene oxide): Coagulant, flocculent, swelling agent
Poly (ethylene glycol): plasticizer, base for suppositories
Poly (vinyl pyrrolidone): Used to make betadine (iodine complex of PVP) with less toxicity than
iodine, plasma replacement, and tablet granulation
Poly (vinyl alcohol): Water-soluble packaging, tablet binder, tablet coating
Polyacrylamide: Gel electrophoresis to separate proteins based on their molecular weights,
coagulant,absorbent
Poly (isopropyl acrylamide) and poly (cyclopropyl methacrylamide): Thermogelling acrylamide
derivatives, its balance of hydrogen bonding, and hydrophobic association changes with
temperature
Cellulose-Based Polymers
Ethyl cellulose: Insoluble but dispersible in water, aqueous coating system for sustained release
applications
Carboxymethyl cellulose: Superdisintegrant, emulsion stabilizer
Hydroxyethyl and hydroxypropyl celluloses: Soluble in water and in alcohol, tablet coating
Hydroxypropyl methyl cellulose: Binder for tablet matrix and tablet coating, gelatin alternative
as capsule material
Cellulose acetate phthalate: Enteric coating
Hydrocolloids
Alginic acid: Oral and topical pharmaceutical products; thickening and suspending agent in a
variety of pastes, creams, and gels, as well as a stabilizing agent for oil-in-water emulsions;
binder and disintegrant
Carrageenan: Modified release, viscosifier
Chitosan: Cosmetics and controlled drug delivery applications, mucoadhesive dosage forms,
rapid release dosage forms
Hyaluronic acid: Reduction of scar tissue, cosmetics
Pectinic acid: Drug delivery
Water-Insoluble Biodegradable Polymers
(Lactide-co-glycolide) polymers: Microparticle–nanoparticle for protein delivery
Starch-Based Polymers
Starch: Glidant, a diluent in tablets and capsules, a disintegrant in tablets and capsules, a tablet
binder
Sodium starch glycolate: Superdisintegrant for tablets and capsules in oral delivery
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manikrupharmacy@gmail.com; Lecturer; Department of Pharmacy; Primeasia University.
Plastics and Rubbers
Polyurethane: Transdermal patch backing (soft, comfortable, moderate moisture transmission),
blood pump, artificial heart, and vascular grafts, foam in biomedical and industrial products
Silicones: Pacifier, therapeutic devices, implants, medical grade adhesive for transdermal
delivery
Polycarbonate: Case for biomedical and pharmaceutical products
Polychloroprene: Septum for injection, plungers for syringes, and valve components
Polyisobutylene: Pressure sensitive adhesives for transdermal delivery
Polycyanoacrylate: Biodegradable tissue adhesives in surgery, a drug carrier in nano- and
microparticles
Poly (vinyl acetate): Binder for chewing gum
Polystyrene: Petri dishes and containers for cell culture
Polypropylene: Tight packaging, heat shrinkable films, containers
Poly (vinyl chloride): Blood bag, hoses, and tubing
Polyethylene: Transdermal patch backing for drug in adhesive design, wrap, packaging,
containers
Poly (methyl methacrylate): Hard contact lenses
Poly (hydroxyethyl methacrylate): Soft contact lenses
Ethylene vinyl acetate and polyethylene terephthalate:Transdermal patch backing (occlusive, heat
sealable, translucent)
Ethylene vinyl acetate and polyethylene: Transdermal patch backing (heat sealable, occlusive,
translucent)
Polyethylene and polyethylene terephthalate: Transdermal patch backing (when ethylene vinyl
acetate copolymer is incompatible with the drug)
PLASTICIZER
A plasticizer or softener is a substance incorporated in a material (usually a plastic) to increase
the flexibility, elongation, workability, dispensability.
A Plasticizer is a distinct polymer additive, that increase the plasticity or viscosity of a material.
Ideal properties of plasticizers:
1. It should be flexible resilient (থিথিিাপক /elastic) and easier to handle.
2. It should be non-volatile with high boiling point.
3. It should not come out from materials to which it is added.
4. Plasticizers used for internal purpose should be non-toxic.
5. It should lower the tensile strength and softening temperature, of the polymeric materials
to which it is added.
6. It should reduce the brittleness, improve flow, flexibility, and increase toughness, shear
strength, and impart resistance to the polymeric film coating.
7. It should lower the glass transition temperature of the polymeric film coating.
8. It should reduce the viscosity of materials to which it is added.
9. It should impart permanent properties such as liability, shock resistance, hand drop.
10. The main role of the plasticizer is to improve mechanical properties of the polymers by
increasing flexibility, decreasing tensile strength and lowering the second order
transition temperature.
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Why do we need plasticizers?
Almost all the film forming agents or polymers are brittle in nature due to their complex
structure. Most commonly used polymers are the cellulose derivatives or cellulose related
compounds like HPMC, MC, EC, Nitrocellulose, HPMCP etc. These polymers are widely used as
film forming materials as they:-
Produce transparent films
Produce intact films
They have lower values for water vapor permeability rate.
They have lower values for oxygen transmission rates.
They can be structurally modified to achieve sustained release, like HPMC can be converted to
HPMCP for enteric coating. But due to presence of multiple polymeric strands within a single
molecule of polymer makes them brittle. When such a material is applied as a film coat on to
tablet a smooth film will not be obtained. This condition necessitates the addition of plasticizers
to the coating/Film forming dispersions. The addition of plasticizers to polymeric material
causes them to diffuse within the polymers and cause polymer deformation and coalescence
into homogeneous films.
The effectiveness of plasticizers on polymeric dispersion depends upon polymer compatibility
and the permanence of plasticizer during the course of shelf life, or when it comes in contact
with physiological fluids.
Effect of Plasticizers
• Easy melt
• Improve flexibility
• Increase Softness and Flexibility.
• Improve Process ability.
• Alters Softening point, Tensile Strength, Elongation at break & Impact.
Mechanism of action
The mechanism of action of plasticizers is defined as to interpose between every
individual strand of polymer and thereby causing breakdown of polymer -polymer
interactions.
The tertiary structure of the polymer is modified into more porous, flexible and with less
cohesive structure.
Plasticizers soften and swell the polymer (latex spheres) which aids in overcoming their
resistance to deformation.
As a result the plasticized polymer would deform at a lower tensile force as compared to
without plasticizer. This enhances the polymer -plasticizer interaction.
This effect in turn enhances the film elongation effect.
This interaction to a greater extend depends upon the glass transition temperature of
polymers. Glass transition temperature, Tg is the temperature at which hard glassy
polymer is converted into a rubbery material.
All polymers have higher glass transition temperatures and addition of plasticizers
reduces the glass transition temperature.
As plasticizers usually possess relatively long alkyl chains, they have the effect of
screening the polymer chains from each other, thereby preventing them from re-forming
the chain-chain interactions which give the unplasticized polymer its rigidity.
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Plasticization
Plasticization, in general, refers to a change in the thermal and mechanical properties of a given
polymer which involves:
(a) Lowering of rigidity at room temperature;
(b) Lowering of temperature, at which substantial deformations can be effected with not too
large forces;
(c) Incensement of the elongation to break at room temperature;
(d) Incensement of the toughness (impact strength) down to the lowest temperature of
serviceability.
These effects can be achieved:
(1) By compounding the given polymer with a low molecular weight compound or with another
polymer and
(2) By introducing into the original polymer a comonomer (one of the constituents of a
copolymer) which reduces crystallizability and increases chain flexiblity
Plasticization theories
There are mainly 03 theories regarding plasticization. Therese are as follows.
Lubricity theory:
According to Lubricity Theory the Plasticizer acts as a lubricant, reducing
intermolecular friction between polymer molecules responsible for rigidity of the
polymer.
This theory a.ssumes the rigidity of the resin (pure polymer) arises from “intermolecular
friction.”
A “dry” polymer, a resin without plasticizer, is rigid because friction exists between its
chains, binding them into a network.
When the polymer is heated in order to be plasticized, the binding is weakened and the
smaller plasticizer molecules are able to slip in between the chains.
When the polymer cools, the plasticizer molecules act as a lubricant between the chains,
allowing them to “slip.”
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Gel theory:
According to Gel Theory the Polymers are formed by an internal three-dimensional
network.
The plasticizer molecules break up the polymer-polymer interaction by getting in
between the chains and “obscuring” these interaction sites from the polymer molecules.
Resin-resin interactions occur at “centers of attachment.”
Plasticizer molecules break these interactions and masks the centers from each other,
preventing re-formation.
This theory is not sufficient to describe interaction– should be combined with Lubricity
Theory.
The free volume theory:
According to the Free Volume Theory the Plasticizer lowers the glass transition
temperature (Tg) of the polymer.
The free volume of a polymer can be described as the “empty internal space” available
for the movement of the polymer chains. The free volume of a polymer greatly increases
when it reaches the glass transition temperature.
At the glass transition temperature, the molecular motion begins to occur, which
corresponds to an increase in the free volume of the polymer.
Plasticizer is meant to decrease the glass transition temperature, imparting increased
flexibility to polymer at room temperature.
These plasticizer molecules are having low glass transition temperature than the
polymer, so that Tg of the resulting mixture will be lower.
Mechanistic Theory: Plasticizer molecules are not bound permanently to the polymer
molecules form.
PLASTICIZERS IN FILM COATING
There are more than 300 different types of plasticizers available. The most commonly used
plasticizers are ester like phthalates, adipates and trimellitates.
The commonly used plasticizers can be categorized into three groups:
1. Polyols:
(a) Glycerol (glycerin);
(b) Propylene glycol;
(c) Polyethylene glycols PEG (generally the 200–6000 grades).
2. Organic esters:
(a) Phthalate esters (diethyl, dibutyl);
(b) Dibutyl sebacete;
(c) Citrate esters (triethyl, acetyl triethyl, acetyl tributyl);
(d) Triacetin.
3. Oils/ glycerides:
(a) Castor oil;
(b) Acetylated monoglycerides;
(c) Fractionated coconut oil
4. Newer Plasticizers – DBS (Dibutyl Sebacate).
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Plasticized Polymers
A plasticizer is added to a polymer formulation to enhance its flexibility and to help its
processing. It facilitates relative movement of polymer chains against each other. The addition
of a plasticizer to a polymer results in a reduction in the glass transition temperature of the
mixture. Since plasticizers increase molecular motion, drug molecules can diffuse through the
plasticized polymer matrix at a higher rate depending on the plasticizer concentration.
Example: Plasticized Polymers
Fluoxetine (ProzacWeekly) (fluoxetine hydrochloride) capsules contain hydroxypropyl
methylcellulose and hydroxypropyl cellulose acetate succinate plasticized with sodium lauryl
sulfate and triethyl citrate.
Omeprazole magnesium (Prilosec), a delayed release oral suspension, contains
hydroxypropyl cellulose, hydroxypropyl methylcellulose, and methacrylic acid copolymer
plasticized with glyceryl monostearate, triethyl citrate, and polysorbate.
Triacetin can be found in ranitidine HCl (Zantac) 150-tablet formulations, which contains
hydroxypropyl methylcellulose as its polymer matrix.
Dibutyl sebacate is found in methylphenidate HCl (Metadate) CDwhich contains polymers
such as povidone, hydroxypropyl methylcellulose, and ethyl cellulose.
Elastomers
An elastomer is a polymer with viscoelasticity (having both viscosity and elasticity) .The term,
which is derived from elastic polymer, is often used interchangeably with the term rubber,
although the latter is preferred when referring to vulcanisates.
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Elastomeric materials are those materials that are made of polymers that are joined by
chemical bonds, acquiring a final slightly cross-linked structure. The main characteristic of
elastomer materials is the high elongation and flexibility or elasticity of these materials,
against its breaking or cracking.
Depending on the distribution and degree of the chemical bonds of the polymers, elastomeric
materials can have properties or characteristics similar to thermosets or thermoplastics, so
elastomeric materials can be classified into:
1. Thermoset Elastomers - are those elastomer materials which do not melt when heated.
2. Thermoplastic Elastomers - are those elastomers which melt when heated.
Properties of elastomer materials:
1. Do not melt (before melting they pass into a gaseous state.).
2. Swell in the presence of certain solvents.
3. Generally insoluble.
4. Flexible and elastic.
5. Lower creep resistance than the thermoplastic materials.
Examples and applications of elastomer plastic materials:
1. Natural rubber – It is used in the pharmaceutical vial closures.
2. Polyurethanes – Generally they are used in these medical applications:
a) Diaphragms
b) Membranes
c) Surgical apparatus
d) Mechanical supports
3. Neoprene – It is used primarily in the manufacture of Medical gloves.
4. Silicone – Silicones are used in a wide range of materials and areas due their excellent
thermal and chemical resistance. Silicones are used today in many life-saving medical
devices like pacemakers or hydrocephalic shunts. They are also used as excipients in
topical formulations or adhesives to affix transdermal drug delivery systems. They also
have found use as active pharmaceutical ingredients in products such as antacid and
antiflatulent formulations.
5. Medical Thermoplastic elastomers (TPE) products include drip chambers, seals, medical
hoses, artificial skin to many of the artificial human body parts, drug encapsulation
purposes etc.