The document discusses preformulation studies that are conducted to characterize the physical, chemical, and mechanical properties of new drug substances. It covers topics like solubility, permeability, polymorphism, hygroscopicity, particle size, and powder flow properties. The objectives of preformulation are to develop stable, safe, and effective dosage forms and generate useful information for formulating an optimal drug delivery system. It also discusses various analytical methods used to characterize solid forms during preformulation.
Preformulation is a group of studies that focus on the physicochemical properties of a new drug candidate that could affect the drug performance and the development of a dosage form. ... This property provides the framework for drugs combination with pharmaceutical ingredients in the fabrication of dosage form.
Preformulation is a group of studies that focus on the physicochemical properties of a new drug candidate that could affect the drug performance and the development of a dosage form. ... This property provides the framework for drugs combination with pharmaceutical ingredients in the fabrication of dosage form.
It is a small presentation about the preformulation studies, which help students in their exams.
Preformulation is a crucial stage in pharmaceutical research and development that encompasses a series of scientific studies and experiments conducted before the formulation of a drug product begins. Its primary purpose is to gather essential information and data about the physical, chemical, and biopharmaceutical properties of a drug substance or active pharmaceutical ingredient (API).
Understanding the Drug Substance:
Preformulation starts with a comprehensive characterization of the drug substance. This includes identifying its chemical structure, molecular weight, and purity. Various analytical techniques are employed for this purpose, such as nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and high-performance liquid chromatography (HPLC).
2. Assessing Physicochemical Properties:
Preformulation studies delve into the physicochemical properties of the drug substance. Researchers investigate properties such as solubility, melting point, crystallinity, hygroscopicity, and polymorphism. These properties can profoundly affect formulation design and stability.
Preformulation and physicochemical property of the drugSHIVANEE VYAS
“It is the study of the physical and chemical properties of the
drug prior to compounding process”.
Preformulation commences when a newly synthesized drug shows sufficient pharmacologic promise in animal models towarrant evaluation in man.
These studies should focus on physicochemical properties of new compound that affect drug performance & development of efficaciouss dosage form.
This properties may provide;
A rationale for formulation design
Support the need for molecular modification.
The chapter deals with the preformulation studies that have to be considered while designing a dosage form and developing a formulation that is suitable for a patient. Here, physical and chemical properties of a drug substance are studied along with biopharmaceutical classification of drugs. Also a detailed study on the application of preformulation studies in different dosage forms are also studied.
A drug injected intravascularly directly enters the systemic circulation and exerts its pharmacological effects.
Majority of drugs administered extravascularly, generally orally.
If intended to act systemically, such drugs can exert their pharmacological actions only when they come into blood circulation from their site of application. So, absorption is an important step.
Struggling with intense fears that disrupt your life? At Renew Life Hypnosis, we offer specialized hypnosis to overcome fear. Phobias are exaggerated fears, often stemming from past traumas or learned behaviors. Hypnotherapy addresses these deep-seated fears by accessing the subconscious mind, helping you change your reactions to phobic triggers. Our expert therapists guide you into a state of deep relaxation, allowing you to transform your responses and reduce anxiety. Experience increased confidence and freedom from phobias with our personalized approach. Ready to live a fear-free life? Visit us at Renew Life Hypnosis..
It is a small presentation about the preformulation studies, which help students in their exams.
Preformulation is a crucial stage in pharmaceutical research and development that encompasses a series of scientific studies and experiments conducted before the formulation of a drug product begins. Its primary purpose is to gather essential information and data about the physical, chemical, and biopharmaceutical properties of a drug substance or active pharmaceutical ingredient (API).
Understanding the Drug Substance:
Preformulation starts with a comprehensive characterization of the drug substance. This includes identifying its chemical structure, molecular weight, and purity. Various analytical techniques are employed for this purpose, such as nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and high-performance liquid chromatography (HPLC).
2. Assessing Physicochemical Properties:
Preformulation studies delve into the physicochemical properties of the drug substance. Researchers investigate properties such as solubility, melting point, crystallinity, hygroscopicity, and polymorphism. These properties can profoundly affect formulation design and stability.
Preformulation and physicochemical property of the drugSHIVANEE VYAS
“It is the study of the physical and chemical properties of the
drug prior to compounding process”.
Preformulation commences when a newly synthesized drug shows sufficient pharmacologic promise in animal models towarrant evaluation in man.
These studies should focus on physicochemical properties of new compound that affect drug performance & development of efficaciouss dosage form.
This properties may provide;
A rationale for formulation design
Support the need for molecular modification.
The chapter deals with the preformulation studies that have to be considered while designing a dosage form and developing a formulation that is suitable for a patient. Here, physical and chemical properties of a drug substance are studied along with biopharmaceutical classification of drugs. Also a detailed study on the application of preformulation studies in different dosage forms are also studied.
A drug injected intravascularly directly enters the systemic circulation and exerts its pharmacological effects.
Majority of drugs administered extravascularly, generally orally.
If intended to act systemically, such drugs can exert their pharmacological actions only when they come into blood circulation from their site of application. So, absorption is an important step.
Struggling with intense fears that disrupt your life? At Renew Life Hypnosis, we offer specialized hypnosis to overcome fear. Phobias are exaggerated fears, often stemming from past traumas or learned behaviors. Hypnotherapy addresses these deep-seated fears by accessing the subconscious mind, helping you change your reactions to phobic triggers. Our expert therapists guide you into a state of deep relaxation, allowing you to transform your responses and reduce anxiety. Experience increased confidence and freedom from phobias with our personalized approach. Ready to live a fear-free life? Visit us at Renew Life Hypnosis..
CHAPTER 1 SEMESTER V - ROLE OF PEADIATRIC NURSE.pdfSachin Sharma
Pediatric nurses play a vital role in the health and well-being of children. Their responsibilities are wide-ranging, and their objectives can be categorized into several key areas:
1. Direct Patient Care:
Objective: Provide comprehensive and compassionate care to infants, children, and adolescents in various healthcare settings (hospitals, clinics, etc.).
This includes tasks like:
Monitoring vital signs and physical condition.
Administering medications and treatments.
Performing procedures as directed by doctors.
Assisting with daily living activities (bathing, feeding).
Providing emotional support and pain management.
2. Health Promotion and Education:
Objective: Promote healthy behaviors and educate children, families, and communities about preventive healthcare.
This includes tasks like:
Administering vaccinations.
Providing education on nutrition, hygiene, and development.
Offering breastfeeding and childbirth support.
Counseling families on safety and injury prevention.
3. Collaboration and Advocacy:
Objective: Collaborate effectively with doctors, social workers, therapists, and other healthcare professionals to ensure coordinated care for children.
Objective: Advocate for the rights and best interests of their patients, especially when children cannot speak for themselves.
This includes tasks like:
Communicating effectively with healthcare teams.
Identifying and addressing potential risks to child welfare.
Educating families about their child's condition and treatment options.
4. Professional Development and Research:
Objective: Stay up-to-date on the latest advancements in pediatric healthcare through continuing education and research.
Objective: Contribute to improving the quality of care for children by participating in research initiatives.
This includes tasks like:
Attending workshops and conferences on pediatric nursing.
Participating in clinical trials related to child health.
Implementing evidence-based practices into their daily routines.
By fulfilling these objectives, pediatric nurses play a crucial role in ensuring the optimal health and well-being of children throughout all stages of their development.
Defecation
Normal defecation begins with movement in the left colon, moving stool toward the anus. When stool reaches the rectum, the distention causes relaxation of the internal sphincter and an awareness of the need to defecate. At the time of defecation, the external sphincter relaxes, and abdominal muscles contract, increasing intrarectal pressure and forcing the stool out
The Valsalva maneuver exerts pressure to expel faeces through a voluntary contraction of the abdominal muscles while maintaining forced expiration against a closed airway. Patients with cardiovascular disease, glaucoma, increased intracranial pressure, or a new surgical wound are at greater risk for cardiac dysrhythmias and elevated blood pressure with the Valsalva maneuver and need to avoid straining to pass the stool.
Normal defecation is painless, resulting in passage of soft, formed stool
CONSTIPATION
Constipation is a symptom, not a disease. Improper diet, reduced fluid intake, lack of exercise, and certain medications can cause constipation. For example, patients receiving opiates for pain after surgery often require a stool softener or laxative to prevent constipation. The signs of constipation include infrequent bowel movements (less than every 3 days), difficulty passing stools, excessive straining, inability to defecate at will, and hard feaces
IMPACTION
Fecal impaction results from unrelieved constipation. It is a collection of hardened feces wedged in the rectum that a person cannot expel. In cases of severe impaction the mass extends up into the sigmoid colon.
DIARRHEA
Diarrhea is an increase in the number of stools and the passage of liquid, unformed feces. It is associated with disorders affecting digestion, absorption, and secretion in the GI tract. Intestinal contents pass through the small and large intestine too quickly to allow for the usual absorption of fluid and nutrients. Irritation within the colon results in increased mucus secretion. As a result, feces become watery, and the patient is unable to control the urge to defecate. Normally an anal bag is safe and effective in long-term treatment of patients with fecal incontinence at home, in hospice, or in the hospital. Fecal incontinence is expensive and a potentially dangerous condition in terms of contamination and risk of skin ulceration
HEMORRHOIDS
Hemorrhoids are dilated, engorged veins in the lining of the rectum. They are either external or internal.
FLATULENCE
As gas accumulates in the lumen of the intestines, the bowel wall stretches and distends (flatulence). It is a common cause of abdominal fullness, pain, and cramping. Normally intestinal gas escapes through the mouth (belching) or the anus (passing of flatus)
FECAL INCONTINENCE
Fecal incontinence is the inability to control passage of feces and gas from the anus. Incontinence harms a patient’s body image
PREPARATION AND GIVING OF LAXATIVESACCORDING TO POTTER AND PERRY,
An enema is the instillation of a solution into the rectum and sig
India Clinical Trials Market: Industry Size and Growth Trends [2030] Analyzed...Kumar Satyam
According to TechSci Research report, "India Clinical Trials Market- By Region, Competition, Forecast & Opportunities, 2030F," the India Clinical Trials Market was valued at USD 2.05 billion in 2024 and is projected to grow at a compound annual growth rate (CAGR) of 8.64% through 2030. The market is driven by a variety of factors, making India an attractive destination for pharmaceutical companies and researchers. India's vast and diverse patient population, cost-effective operational environment, and a large pool of skilled medical professionals contribute significantly to the market's growth. Additionally, increasing government support in streamlining regulations and the growing prevalence of lifestyle diseases further propel the clinical trials market.
Growing Prevalence of Lifestyle Diseases
The rising incidence of lifestyle diseases such as diabetes, cardiovascular diseases, and cancer is a major trend driving the clinical trials market in India. These conditions necessitate the development and testing of new treatment methods, creating a robust demand for clinical trials. The increasing burden of these diseases highlights the need for innovative therapies and underscores the importance of India as a key player in global clinical research.
QA Paediatric dentistry department, Hospital Melaka 2020Azreen Aj
QA study - To improve the 6th monthly recall rate post-comprehensive dental treatment under general anaesthesia in paediatric dentistry department, Hospital Melaka
How many patients does case series should have In comparison to case reports.pdfpubrica101
Pubrica’s team of researchers and writers create scientific and medical research articles, which may be important resources for authors and practitioners. Pubrica medical writers assist you in creating and revising the introduction by alerting the reader to gaps in the chosen study subject. Our professionals understand the order in which the hypothesis topic is followed by the broad subject, the issue, and the backdrop.
https://pubrica.com/academy/case-study-or-series/how-many-patients-does-case-series-should-have-in-comparison-to-case-reports/
CRISPR-Cas9, a revolutionary gene-editing tool, holds immense potential to reshape medicine, agriculture, and our understanding of life. But like any powerful tool, it comes with ethical considerations.
Unveiling CRISPR: This naturally occurring bacterial defense system (crRNA & Cas9 protein) fights viruses. Scientists repurposed it for precise gene editing (correction, deletion, insertion) by targeting specific DNA sequences.
The Promise: CRISPR offers exciting possibilities:
Gene Therapy: Correcting genetic diseases like cystic fibrosis.
Agriculture: Engineering crops resistant to pests and harsh environments.
Research: Studying gene function to unlock new knowledge.
The Peril: Ethical concerns demand attention:
Off-target Effects: Unintended DNA edits can have unforeseen consequences.
Eugenics: Misusing CRISPR for designer babies raises social and ethical questions.
Equity: High costs could limit access to this potentially life-saving technology.
The Path Forward: Responsible development is crucial:
International Collaboration: Clear guidelines are needed for research and human trials.
Public Education: Open discussions ensure informed decisions about CRISPR.
Prioritize Safety and Ethics: Safety and ethical principles must be paramount.
CRISPR offers a powerful tool for a better future, but responsible development and addressing ethical concerns are essential. By prioritizing safety, fostering open dialogue, and ensuring equitable access, we can harness CRISPR's power for the benefit of all. (2998 characters)
2. Preformulation
Preformulation may be described as a phase of the research
and development process where the preformulation
scientist characterizes the physical, chemical and
mechanical properties of a new drug substance, in order to
develop stable, safe and effective dosage form.
The word preformulation is composed of two words pre
and formulation. Activities done prior to formulation
development are called as preformulation studies. It
provides the scientific basis for formulation development.
3. Objectives
The preformulation investigations confirm that
there are no significant barriers to the
compound’s development as a marketed drug.
The formulation scientist uses these information's
to develop dosage forms.
4. Significance
Preformulation studies helps to develop the elegant
dosage forms (stable, effective & safe).
It is important to have an understanding of the physical
description of a drug substance before dosage form
development.
It is 1st step in rational development of a dosage form of
a drug substance before dosage form development.
It generates useful information to the formulator to
design an optimum drug delivery system
It helps to establish the kinetic rate profile of new drug
substance with their compatibility with the common
excipients.
5. Classification of preformulation study.
There are two classes of preformulaion study
1. fundamental preformulation,
2. derived preformulation
6. Fundamental preformulation
These are specific to the drug molecule and are dependent on
the chemical structure of the drug molecule. Such as
• Solubility: solubility in different solvents, dissociation
constant (pKa), salt formation, partition or distribution
coefficient (log P or log D), pH solubility profile and
dissolution kinetics,
• Permeability,
• Solid state properties like solid form, crystalinity,
polymorphism, solvated forms and amorphous form
• Solid state stability and solution state stability, wherein
inherent stability, pH – stability profile and photo-stability
are studied.
7. Derived preformulation:
These properties are carried out to learn about the
issues related to development of a particular
dosage form like solid oral, liquid oral or parenteral.
Derived preformulation properties are specific to
the intended dosage form to be developed. For
solid oral dosage form like tablet, include –
• characterization of particle properties like
morphology and particle size
• bulk density
• flow properties and
• compaction behavior
Cont……
8. In case a capsule dosage form is to be developed,
compaction behavior, shall not be required. The
last activity performed in pre-formulation studies
is the compatibility studies, wherein the physical
and chemical stability of the drug molecule is
studied in presence of excipients. Obviously, the
choice of excipients is dictated by the type of
dosage form to be developed.
9. Preliminary evaluation and molecular optimization
Once a pharmaceutically active compound has been identified,
a project team consisting of representatives from the
disciplines indicated in the following figures has
responsibility for assuring that the compound enters the
development process in its optimum molecular form. While
each discipline may have its own criteria for an ‘optimized’
molecule, the physical pharmacist must focus on how the
product will be formulated and administered to patients.
Commonly, stability and/or solubility shortcomings can
adversely affect these aspects of drug performance.
Cont…..
10. When the first quality sample of the new drug becomes
available, probing experiments should be conducted to
determine the magnitude of each suspected problem areas.
If a deficiency is detected, then the project team should
decide on the molecular modifications that would most
likely improve the drugs properties. Salts, prodrugs,
solvates, polymorph or even new analogs may emerge from
this modification effort.
11.
12. Following figure shows how drug formulation goes in to market
stepwise representation is mentioned in it.
13. Major area of preformulation research:
1. Bulk characterization:
Crystallinity & polymorphism
Hygroscopicity
Fine particle characterization
Powder flow properties.
2. Solubility analysis:
Ionization constant Pka
pH solubility profile
Common ion effect-Ksp
Solubilization
Dissolution
Partition co-efficient
Cont……
15. Bulk characterization
When a drug molecule is discovered all the solid
forms are hardly identified. So during bulk
characterization the following characteristics
are studied.
1. Crystallinity & polymorphism
2. Hygroscopicity
3. Fine particle characterization
4. Powder flow properties.
16. Crystallinity & polymorphism
Crystal habit & internal structure of drug can affect
physic-chemical properties which range from flow
ability to chemical stability. Habit means the
description of outer appearance of a crystal. While
internal structure describes the molecular
arrangement within the solid, changes in internal
structure usually alter crystal habit.
Ex. 1: Conversion of sodium salt to its free acid form
produce both a change in internal structure & crystal
habit.
Ex. 2: Conversion of Sod. Benzoate to Benzoic acid.
18. Idea about salts, solvates, hydrates and co-crystals
Figure. 3: General idea about polymorphs, amorphous, solvates,
salts, and co-crystals.
19. Crystalline
Crystals are characterized by repetitious spacing of
constituent atoms or molecule in a dimensional
array. Evaluation of crystal structure,
polymorphism, & solvate form is an important
preformulation activity. The changes in crystal
characteristics can influence bioavailability,
chemical and physical stability, & can have
implication in dosage form process functions. It can
be a significant factor relating to tablet formulation
because of flow and compaction behavior among
other.
e.g. Nacl, CsCl crystal.
20. Crystal morphology
Repetition of atom or molecule in regular three
dimensional arrays (structure) there are six
crystalline systems
1. Cubic
2. Tetragonal
3. Orthorhombic
4. Monoclinic
5. Triclinic
6. Hexagonal.
21.
22. Amorphous / non crystalline
In this forms the solids do not have any fixed
internal structure. They have atoms or molecules
randomly placed as in a liquid. Due to higher
thermodynamic energy of amorphous form than
crystalline form they shows greater dissolution
rates and upon standing amorphous forms tends to
reverts to more stable forms. This thermodynamic
instability is a major disadvantage for developing
amorphous forms.
e.g. Amorphous Novobiocin.
24. Polymorphism(Crystal forms)
When a substance exists in more than one crystalline
form, the various forms are called Polymorphs and
the phenomenon is called polymorphism. e.g .
Chloramphenicol palmitate has three polymorphs A,
B and C. An important factor affect on formulation
is the crystalline or amorphous form of the drug.
Polymorphic form exhibits different physico-
chemical properties including melting point and
solubility. Polymorphic form in drug are relatively
common, it has been estimated that at least 1/3 of all
organic compounds exhibit polymorphism.
25. Types
Polymorphs are two types
1. Enantiotrophic polymorphs,
2. Monotrophic polymorphs
Enantiotrophic polymorphs: Enantiotrophic
polymorphs is the one which can be reversibly
changed into another form by altering the
temperature or pressure.
e.g: Sulfur. Carbon. Nitrogen .Oxygen.
26. Monotrophic polymorphs: The transition take place in only
one direction is called as monotrophic polymorphs. Or is
one which is unstable at all temperature & pressure. Ex:
glyceryl steartes.
The polymorphs differ from each other with respect to their
physical properties, such as solubility, melting point,
density, hardness, dissolution, compression characteristics.
Polymorphs (Drugs and There Polymorphic forms)
Steroids like Progesterone has 5 polymorphs.
Barbiturates like Barbitone have 2, & Pentabarbitone has 3.
A sulphonamide like Sulphabenzamide has 4 polymorphs &
3 solvates. Caffeine has 2 polymorphs
Chlorpropamide has 3 polymorphs.
27. Properties of solvates / hydrates
Generally, the anhydrous form of a drug has greater
aqueous solubility than its hydrates. This is because
the hydrates are already in equilibrium with water
and therefore have less demand for water. e.g.
anhydrous forms of theophyline and ampicillin have
higher aqueous solubility than the hydrates.
Non aqueous solvates have greater aqueous
solubility than the non-solvates. E.g. chloroform
solvates of griseofulvin are more water soluble than
their non-solvate forms.
28. Effects of polymorphs
Effect on Bioavailablity
Different polymorphic forms of a given drug shows
difference in the dissolution rate & solubility. When
absorption of drug is dissolution rate limited, as more
soluble and faster dissolving form may be utilized to improve
the rate and extent of bioavailability.
For example: Chloramphenicol palmitate Comparative blood
level data obtained in human after oral administration of
1.5gm of pure A & pure B forms of Chloramphenicol
palmitate & their mixtures. These data shows that the pure
form B is more soluble so was most bioavailable. Where as
pure form A is less soluble so least bioavailable.
29. Effect on chemical stability
For drugs prone to degradation in the solid state, the
physical form of drug influence the rate of degradation.
Ex. Aztreonam (monobactam antibiotic) Exist in needle
like α and spherical β-crystalline forms. In the presence
of high humidity ( 37 C / 75% RH),the α-form undergoes
β-lactum hydrolysis more readily with a half life of about
6 months Where as the β-form under identical condition
is stable for several years . In as much as two crystal
forms of labile drugs could exhibit widely different solid
state stabilities. So the Preformulation scientist might
have consider changing the crystal form for eliminating a
stability problem.
30. Effect on tableting behaviors
.
In a typical tableting operation flow and compaction
behaviors of the powder mass to be tableted are
important. These properties among other are related
to morphology, tensile strength, and density, of the
powder bed which becomes significantly different for
two polymorphic forms of same drug.
31. Effect on physical stability
One form of the polymorphic form is thermodynamically
stable at given tempt. & pressure. The other form converts
to the stable form that time. This transformation may be
rapid or slow. The stable polymorph exhibit highest melting
point, the lowest solubility and maximum physical and
chemical stability under safe condition to justify its use for
reason of better dissolution or ease of tableting.
Polymorphic transformation can occur during grinding,
granulation, drying, and compressing operation. Ex.
Digoxine, Spironolacton, and estradiol are reported to
undergo, polymorphic transformation during the size
reduction.
32. Analytical methods for characterization of solid forms
Method Material required per
sample
Microscopy
Hot stage microscopy
Differential Scanning Calorimetry (DSC)
Differential Thermal Analysis (DTA)
Thermogravimetric Analysis
Infrared Spectroscopy
X-ray Powder Diffraction
Scanning Electron Microscopy
Dissolution / Solubility Analysis
1 mg
1 mg
2 – 5 mg
2 – 5 mg
10 mg
2 – 20 mg
500 mg
2 mg
mg to gm
33. Hygroscopicity
Many pharmaceutical materials have a tendency to adsorb
atmospheric moisture (especially water-soluble salt forms).eg. CaO,
NaCl, Sucrose. They are called hygroscopic materials and this
phenomenon is known as hygroscopicity. Most pharmaceutical
compounds lose or gain water from the atmosphere depending on the
relative humidity (RH). Materials unaffected by RH are termed as non
hygroscopic. Pharmaceutical air conditioning is usually set bellow
50%RH and very hygroscopic products that are moisture sensitive are
made and stored below 40% RH. Tablets and capsules must be
hydrophilic to facilitate wetting, deaggregation and dissolution during
drug delivery. As a paradox, they must have limited hygroscopisity to
ensure good chemical and physical stability under all reasonable
climatic condition.
Deliquescent materials: They absorb sufficient amount of moisture and
dissolve completely in it. (e.g. anhydrous calcium chloride).
34. Why do we care about
Hygroscopicity?
Amorphous compounds may take up water and re-crystallize & or
degrade. Anhydrous material may hydrate and become less soluble.
The weight change with sorption may cause errors in potency.
The volume changes associated with water gain and loss may
compromise dosage form integrity.
Changing the solid state form in the dosage form requires regulatory
approval.
Different forms may have different compaction, flow and charging
characteristics.
Prevention of Hygroscopicity
Good packaging ( air tight glass bottles)
Use of foil blisters
Use of desiccants.
35. Significance of hygroscopicity test
1. To decide special handling procedure (with respect to
time).
2. To decide
the storage condition i.e. at low humidity
environment.
special packaging – e.g. with desiccant.
3. Moisture level in a powder sample may affect the flow
ability and compactibility which, are important factors
during tableting and capsule filling.
4. After adsorption of moisture, if hydrates are formed then
solubility of that powder may change affecting the
dissolution characteristics of the material.
5. Moisture may degrade some materials. So humidity of a
material must be controlled.
36. Fine particle characterization
Bulk flow, formulation homogeneity and surface area
controlled processes such as dissolution and chemical
reactivity are directly affected by size, shape, and surface
morphology of drug particles. In general new drug candidate
should be tested during preformulation with the particle size
as is practical to facilitate preparation of homogeneous
samples and maximize the surface area for actions. A light
microscope with a calibrated grid usually provides size and
shape characterization for drug particles. Brauner, Emmet,
and Teller (BET) Nitrogen adsorption is a more precise
measurement for surface area determination and also surface
morphology may be observed by scanning electron
microscopy (SEM).
37. Powder flow properties
Pharmaceutical powders may be classified as a free-flowing or
cohesive (non free flowing). Most flow properties are significantly
affected by changes in particle size, density, shape, electrostatic
charge and adsorbed moisture which may arise from processing or
formulation. As a result, a free flowing drug candidate may become
cohesive during development, thus necessitating an entirely new
formulation strategy. Preformulation powder flow investigation should
quantitatively assess the pharmaceutical consequences of each
process movement and provide direction for the formulation
development project team such as granulation or densification via
slugging, the need for special auger feed equipment or a test system
for evaluating the improvements in flow brought about by
formulation. Free-flowing properties may be characterized by a simple
flow rate apparatus and cohesive powders may be characterized by
tensile testing or evaluated in a shear cell.