This document discusses semisolid dosage forms including ointments, creams, and gels. It defines these forms, describes common ingredients used in their preparation such as bases, preservatives, and gelling agents. Methods of preparation including fusion and emulsification are outlined. The document also discusses ideal properties and how these forms are evaluated based on parameters like penetration, release of active ingredients, and irritation potential.
Semisolid dosage forms: Definitions, classification, mechanisms and factors influencing dermal penetration of drugs. Preparation of ointments, pastes, creams and gels. Excipients used in semi solid dosage forms. Evaluation of semi solid dosages forms
Liquid dosage forms are effective pharmaceutical products containing a mixture of active pharmaceutical ingredients (API/Drug) and non drug components (excipients). It is a dose of a drug used as a medicine for consumption or administration. Many liquid dosage forms are used in the pharmacy, but the most commonly used are syrup, suspension, and elixirs. The general category of liquid oral doses includes a broad range of dosage forms, broadly classified as monophasic and biphasic. Whereas dosage forms in both types comprise at least one drug, monophasic forms are homogeneous and completely dissolve in liquid, whereas biphasic forms in a vehicle do not dissolve.
Semisolid dosage forms: Definitions, classification, mechanisms and factors influencing dermal penetration of drugs. Preparation of ointments, pastes, creams and gels. Excipients used in semi solid dosage forms. Evaluation of semi solid dosages forms
Liquid dosage forms are effective pharmaceutical products containing a mixture of active pharmaceutical ingredients (API/Drug) and non drug components (excipients). It is a dose of a drug used as a medicine for consumption or administration. Many liquid dosage forms are used in the pharmacy, but the most commonly used are syrup, suspension, and elixirs. The general category of liquid oral doses includes a broad range of dosage forms, broadly classified as monophasic and biphasic. Whereas dosage forms in both types comprise at least one drug, monophasic forms are homogeneous and completely dissolve in liquid, whereas biphasic forms in a vehicle do not dissolve.
Semisolid dosage forms are neither solid nor liquid, however, they are a combination or mixture of both, and they used for both local and systemic effects. Pharmaceutical semisolid dosage forms such as creams, ointments, gels, suppositories, and paste are used for topical application. Semisolid dosage forms are intended used as drug carriers that are transported topically through the skin, buckle tissue, rectal tissue, outer ear lining nasal mucosa, urethral membrane, vagina, and cornea. The semisolid may adhere adequately before washing on the surface of the application; this helps to extend the supply of drugs on the application site.
Semisolid dosage forms are neither solid nor liquid, however, they are a combination or mixture of both, and they used for both local and systemic effects. Pharmaceutical semisolid dosage forms such as creams, ointments, gels, suppositories, and paste are used for topical application. Semisolid dosage forms are intended used as drug carriers that are transported topically through the skin, buckle tissue, rectal tissue, outer ear lining nasal mucosa, urethral membrane, vagina, and cornea. The semisolid may adhere adequately before washing on the surface of the application; this helps to extend the supply of drugs on the application site.
Semisolid Dosage Form: Ointment, creams & Gel.
Learn more with me Asst. Prof. Mr. Manohar D. Kengar, Nootan College of Pharmacy, Kavathemahankal.
Suppository Dosage Form: Type of Suppository, Preparation method, Evaluation
https://youtu.be/NUgFoLuT3cs
his presentation delves into the formulation, advantages, and applications of semisolid dosage forms, including creams, ointments, and gels. Learn about their unique properties, manufacturing processes, and considerations for drug delivery. Whether you're a student or a pharmaceutical professional, this presentation offers valuable insights into this essential aspect of medication delivery.
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
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.
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
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TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
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
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
2. Semisolid dosage form
• INTRODUCTION
• Pharmaceutical semisolid dosage preparations
include :ointments, pastes, cream, plasters, gels
and rigid foams.
• They contain one or more active ingredients
dissolved or uniformly dispersed in a suitable base
and any suitable excipients such as emulsifiers,
viscosity increasing agents, anti microbial agents,
antioxidants, or stabilizing agents etc..
3. DEFINITION
• Semi solids are the topical dosage form used
for the therapeutic, protective or cosmetic
function. They may be applied to the skin, or
used nasally, vaginally, or rectally…
4. Advantage of semi-solid dosage form:
• It is used externally
• Probability of side effect can be reduce
• First pass gut and hepatic metabolism is avoided.
• Local action and Site specific action of drug on
affected area.
• Convenient for unconscious patient or patient
having difficulty on oral administration.
• Suitable dosage form for bitter drugs.
• More stable than liquid dosage form
5. Disadvantages of semi-solid dosage
form:
• There is no dosage accuracy in this type of dosage
form
• The base which is used in the semi-solid dosage form
can be easily oxidized.
• May cause staining.
• They are bulky to handle.
• Application with finger may cause contamination.
• Physico-chemically less stable than solid dosage
form.
• May cause irritation or allergy to some patients
6. IDEAL PROPERTIES OF
SEMISOLIDS
• PHYSICAL PROPERTIES:
• Smooth texture
• Elegant in appearance
• Non dehydrating
• Non gritty
• Non greasy and non staining
• Non hygroscopic
7. IDEAL PROPERTIES OF
SEMISOLIDS
• PHYSIOLOGICAL PROPERTIES
• Non irritating
• Do not alter membrane / skin functioning
• Miscible with skin secretion
• Have low sensitization index
• APPLICATION PROPERTIES
• Easily applicable with efficient drug release.
• High aqueous wash ability.
8. PREPARATION OF SEMISOLIDS
DOSAGE FORMS
INGREDIENTS USED IN PREPARATION:
• Bases
• Preservative
• Humectants
• Antioxidants
• Emulsifier
• Gelling agent
• Permeation enhancer
• Buffers
9. 1. BASES:
• It is one of the most important ingredient used
in formulation of semisolid dosage form.
Ointment bases do not merely act as the
carriers of the medicaments, but they also
control the extent of absorption of
medicaments incorporated in them.
10. 1. BASES:
IDEAL PROPERTIES OF A BASE:
They should be:
• Inert, non-irritating and non-sensitizing.
• Compatible with skin pH and the drug.
• Good solvent and/or emulsifying agent.
• Emollient, protective, non-greasy and easily
removable.
• Release medicament readily at the site of application.
• Pharmaceutically elegant and possess good stability
11. CLASSIFICATION OF
BASES :
Ointments bases are classified by the
USP into four general groups:
A- hydrocarbon bases (oleaginous bases)
(Petrolatum , Paraffin, Lanolin…..)
B- absorption bases (cold cream, anhydrus
lanolin …)
C- water-removable bases ( oil in water)
D- water-soluble bases (polyethylene glycol)
12. ANTIOXIDANTS :
Oxygen is a highly reactive atom that is capable
of becoming part of potentially damaging
molecules commonly called “free radicals.”
Free radicals are capable of attacking the
healthy cells of the body, causing them to lose
their structure and function. To prevent this
an antioxidants are added.
E.g. Butylated hydroxy anisole, Butylated
hydroxy toluene
13. PERMEATION ENHANCERS :
• Skin can act as a barrier. With the introduction
of various penetration enhancers, penetration
of the drug through the skin can be improved.
• Oleic acid
14. EMULSIFIER :
• An emulsifier (emulgent) is a substance that
stabilizes an emulsion by increasing its kinetic
stability.
- Must reduce surface tension for proper
emulsification.
- Prevents coalescence.
- Ability to increase the viscosity at low
concentration.
15. •Emulsifying agents
- Sodium lauryl sulfate :O/W emulsion
- Sodium stearate and calcium stearate.
- Glyceryl monostearate: weak W/O emulsifying
agents and used as stabilization agents and emollient
in the O/W emulsion.
16. HUMECTANT:
A humectant is a hygroscopic substance, Humectants are used
to :
• increase the solubility of the active ingredient
• to elevate its skin penetration.
• elevate the hydration of the skin.
BUFFERS:
Buffers are added for various purpose such as :
- Compatibility with skin.
- Drug solubility.
- Drug stability.
- Influence ionization of drug. Skin, due to its weak acidic
nature, tolerates weak acidic preparations.
17. •Antimicrobial preservatives
-To inhibit the growth of contaminating microorganisms,
So require the addition of chemical antimicrobial preservatives to
the formulation
-E.G. para-hydroxybenzoates (parabens), phenols,
benzoic acid, sorbic acid, quaternary ammonium
salts and other compounds.
18. 1- Ointments
• Ointments are homogenous, translucent,
viscous semi-solid preparations, most
commonly a greasy, thick oil (oil 80% - water
20%) intended for external application to the
skin or mucous membrane. They are used as:
- Emollients
- Protective
- Therapeutic
- Prophylactic purpose
19. Classification of ointments
A- Epidermic ointments
• These ointments are intended to produce their action
on the surface of the skin and produce local
effect,they are not absorbed.
• They acts as protectives, antiseptics and parasiticides.
B- Endodermic ointments
• These ointments are intended to release the
medicaments that penetrate into the skin. They are
partially absorbed and acts as emollients, stimulants
and local irritants.
C- Diadermic ointments
• These ointments are intended to release the
medicaments that pass through the skin and produce
systemic effects.
21. Preparation of Ointments
- Both on a large and a small scale, ointments are
prepared by three general methods:
(1) incorporation method
(2) fusion method
(3) emulsification method
The method for a particular preparation depends
primarily upon the nature of the ingredients
22. (1) incorporation
-The components of the ointment are mixed together by
various means until a uniform preparation has been
attained.
- On a small scale, the pharmacist may mix the components
of an ointment in a mortar with a pestle, or a spatula
and an ointment slab may be used to rub the ingredients
together.
24. (2) fusion
By the fusion method, all or some of the components of an
ointment are combined by being melted together and cooled
with constant stirring until congealed.
Those components not melted are generally added to the
congealing mixture as it is being cooled and stirred.
Naturally, heat-labile substances and any volatile components
are added last when the temperature of the mixture is low
enough not to cause decomposition of volatilization of the
components.
26. • In the preparation of ointments having an emulsion type of
formula, the general method of manufacture involves a
melting process as well as an emulsification process.
(3) emulsification
27.
28. Evaluation of ointments
A- Penetration
• Weighed quantities of the ointments are
rubbed over definite areas of the skin for a
given length of time. Thereafter the
unabsorbed ointment is collected from the skin
and weighed. The difference between the
two weights roughly represents the amount
absorbed.
29. Evaluation of ointments
B- RATE OF RELEASE OF MEDICAMENT:
• To assess rate of release of medicament, small
amount of the ointment can be placed on the surface
of nutrient agar contained in a Petri dish.
• If the medicament is bactericidal the agar plate is
previously seeded with a suitable organism like
s.aureus. After asuitable period of incubation, the
zone of inhibition is measured and correlated with the
rate of release.
30. RATE OF RELEASE OF
MEDICAMENT
• smear internal surface of test tubes with thin
layers of ointment, fill the tubes with
saline/serum and after a gap of time estimating
the amount of drug present in the serum/saline.
31. Evaluation of ointments
C- ABSORPTION OF MEDICAMENT
INTO
BLOOD STREAM:
• Definite amount of ointments should be
rubbed through the skin. Under standard
conditions and medicaments are estimated in
the blood plasma or urine
32. Evaluation of ointments
D- IRRITANT EFFECT:
• The irritant effect can also be judged to a
certain extent by injecting the ointment into
thigh muscles and under the abdominal skin of
rats. Reaction are noted at intervals of
24,48,72 and 96 hours. Presence of patches on
the skin within 2 weeks indicate irritancy to
pressing skin
33. 2- creams:
Creams are homogeneous, semi-solid preparations
consisting of opaque emulsion ,contains lipophilic
emulsifying agent . Their consistency depend on the
type of emulsion, either water-in-oil (w/o) or oil-in –
water (o/w), and on the nature of the solids in the
internal phase. Creams are intended for the
application to the skin or certain mucous membranes
for:
- Protective
- Therapeutic
- prophylactic purposes
34. Classification of creams
• Creams containing microspheres
( VIT. A CREAM … 200-250 micron)
• Lamellar faced creams
( liquid paraffin in water emulsion )
• Cream containing liquid nanoparticles
(a w/o cream , more occlusive )
35. Preparation of creams
Steps
- Preparation of oil phase :flack/powder
ingredient are dispersed in mineral oil or
silicone oil ) heating may required for melting
- Hydration of aqueous phase: emulsifiers,
stabilizer, thickener are dispersed in water
heating may required for hydrating
- Forming the emulsion: two phases are
blended under vigorous agitation
- Dispersion of active ingredient
36. Evaluation of creams
A- Rheology:
• . The rheology or viscosity should remain
constant. Rheologic measurements are utilized
to characterize the ease of pouring from a
bottle, squeezing from a tube or container
- maintaining product shape in ajar or after
extrusion, rubbing the product onto the skin
• The viscosity can be measured using
viscometers used for such liquids.
37. Evaluation of creams
B- Sensitivity:
As various types of ingredients are used with occasional
use of antiseptic, hormones. etc., there is a possibility
of sensitization or photosensitization of the skin. This
should be tested before hand. This test is normally
done by patch test on skin and can be either open or
occlusive. The test sample is applied along with a
standard market product at different places and effect
is compared after a period of time.
38. Evaluation of creams
C- Effect of thermal stresses:
It is usual to evaluate the stability of an
emulsion by subjecting it too high and low
temperatures in alternating cycles. The
samples are first exposed to 60 C for a few⁰
hours and then to o to 40 C. Such exposures⁰
are repeated a number of times and emulsion
stability assessed after each cycle.
39. Evaluation of creams
D- phase separation:
The rate and degree of phase separation in an emulsion
can be easily determined by keeping a certain amount
in a graduated cylinder and measuring the volume of
separated phase after definite time intervals. The
phase separation may result from creaming or
coalescence of globules. The phase separation test
can be accelerated by centrifugation at low/moderate
speeds.
40. 3- Gels:
• Gels are homogeneous, clear, semisolid
systems consisting of dispersions of small or
large molecules in an aqueous liquid vehicle
rendered jellylike by the addition of a gelling
agent.
Gels are aqueous colloidal suspensions of the
hydrated forms of insoluble medicament, used
for medication and lubrication.
41. gelling agents
• Among the gelling agents used
- Synthetic macromolecules, such as carbomer
934
- Cellulose derivatives, such as
carboxymethylcellulose or hydroxypropyl
methylcellulose
- Natural gums, such as tragacanth
42. TYPES OF GEL-PHASETYPES OF GEL-PHASE
Single Phase
Gels in which the
macromolecules are uniformly
distributed throughout a liquid
with no apparent boundaries
between the dispersed
macromolecules and the liquid
Usually involve organics
Two Phase(Domain)
When the gel mass consists of
floccules of small distinct
particles
Usually involve inorganics
44. Evaluation of gels
- Drug content -1gm of gel was accurately weighed in a 50ml
of volumetric flask to which 20ml purified water was added
with continuous shaking. Volume was adjusted with a mixture
of 10% methanol in water. Absorbance of the solution with the
blank was measured at 360nm using UV-spectrophotometer.
- Measurement of pH -The pH of gels were determined by
digital pH meter. One gram of gel was dissolved in 100ml of
distilled water and stored at 4°C for two hours.
45. Evaluation of gels
- Viscosity -Brookfield viscometer is used for
determination of viscosity. Gels were filled in jar
and spindle was lowered perpendicularly taking
care that spindle do not touch bottom of the jar.
The spindle was rotated in the gel at increasing
shear rates 0.5, 1, 2.5 and 5rpm. At each speed,
the corresponding dial reading was noted.
46.
47. Evaluation of gels
- Spreadability- A modified apparatus consisting of
two glass slides containing gel in between with the lower
slide fixed to a wooden plate and the upper one attached
to a balance by a hook was used to determine
spreadability.
- Extrudability - A simple method was adopted for
determination of extrudability in terms of weight in grams
required to extrude a 0.5cm ribbon of gel in 10 seconds