Recent advances in sterilization

1. STERILIZATION TECHNIQUES
‘NEWSTERILIZATION METHODS’
Presented by:
NAIR RAHUL RAGHAVAN
1st yr M.Pharm (Pharmaceutics), SRIPMS
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2. Contents
 What is sterilization?
 Methods of sterilizations(traditional methods)
 New sterilization methods
 Conclusion
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3. What is sterilization?
 Sterilization can be defined as any process that
effectively kills or eliminates transmissible agents
(such as fungi, bacteria, viruses and prions) from
a surface, equipment, foods, medications, or
biological culture medium.
 DISINFECTION:
Disinfection describes a process that eliminates
many or all pathogenic microorganisms, except
bacterial endospores
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5. PHYSICAL METHODS
HEAT STERILIZATION:
-Heat sterilization is the most widely used and reliable method of
sterilization, involving destruction of enzymes and other essential cell
constituents
i) Dry Heat (160-180˚C): Oxidative changes occur.
Sterilization for thermostable products, moisture sensitive materials
ii) Moist heat (121-134˚C): Hydrolysis & denaturation occurs
Sterilization is used for moisture-resistant materials
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6.  The efficiency with which heat is able to inactivate
microorganisms is dependent upon
>the degree of heat, the exposure time and
the presence of water.
 The action of heat will be due to induction of lethal
chemical events mediated through the action of water
and oxygen.
 In the presence of water much lower temperature
time exposures are required to kill microbe than in the
absence of water.
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7.  Thermal methods includes:
i) Dry Heat Sterilization
Ex:1. Incineration
2. Red heat
3. Flaming
4. Hot air oven
ii) Moist Heat Sterilization
Ex:1.Dry saturated steam – Autoclaving
2. Boiling water/ steam at atmospheric pressure
3. Hot water below boiling point
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8. Dry heat sterilization
 Temp range of 160-180˚C & exposure time up to 2 hrs
 Good penetrability & non-corrosive nature: useful for sterilizing glass
wares & metal surgical instruments. Also used for sterilizing non-
aqueous thermostable liquids and thermostable powders.
 Dry heat destroys bacterial endotoxins (or pyrogens): applicable for
sterilizing glass bottles which are to be filled
aseptically
 Application: Sterilization of dry powdered
drugs, Suspensions of drug in non aq. solvents,
Oils, fats, waxes, soft & hard paraffin,
Oily injections, implants, ophthalmic ointments
& ointment bases etc 8
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HOT AIR OVEN

9. Moist heat sterilization
 Moist heat sterilization involves the
use of steam in the range of 121-
134˚C. Steam under pressure(upto
15lbs) is used to generate high
temperature needed for sterilization.
 Saturated steam acts as an effective
sterilizing agent
 Application: Sterilization of surgical
dressings & instruments, containers,
closures, medical devices, culture
media, etc
AUTOCLAVE
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10. Radiation sterilization
 EMR e.g. Gamma rays and UV light &
Particulate radiation (e.g. Accelerated electrons).
Major target for these radiation is Microbial DNA.
 Use: Sterilization of heat & moisture sensitive products.
 Gamma-rays (from Cobalt 60) are used to sterilize antibiotic,
hormones, sutures, plastics and catheters etc.
 UV light: Has Lower energy & poor penetrability
Surface sterilization of aseptic work areas; for treatment of
manufacturing grade water; but is not suitable for sterilization of
pharmaceutical dosage forms.
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11. Filtration sterilization
 Does not destroy but removes the microorganisms
Used for clarification and sterilization of liquids and gases
 The major mechanisms of filtration are Sieving, Adsorption
and Trapping within the matrix of the filter material
Ex: HEPA FILTERS
 Used in the treatment of heat sensitive injections &
ophthalmic solutions, biological pdts & air & other gases for
supply to aseptic areas.
 Used in industry as part of the venting systems on
fermentors, centrifuges, autoclaves and freeze driers.
 Membrane filters are used for sterility testing 11
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12.  2 types of filters used:
(a)Depth filters: fibrous or granular materials so packed as
to form twisted channels of minute dimensions. Made of
diatomite, porcelain, sintered glass or asbestos.
(b)Membrane filters: Porous membrane 0.1 mm thick,
made of cellulose acetate, cellulose nitrate,
polycarbonate, etc.
Membranes are supported on a frame and held in special
holders. Fluids are made to transverse membranes by
positive or negative pressure or by centrifugation.
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13. CHEMICAL METHODS
GASEOUS STERILIZATION
-Gases like formaldehyde & ethylene oxide have biocidal activity
–MOA: Alkylations of sulphydryl, amino, hydroxyl and carboxyl groups on
proteins & amino gps of nucleic acids.
-Conc. Range 800- 1200 mg/L for ethylene oxide & 15-100 mg/L for
formaldehyde with operating temperatures of 45-63°C & 70-75°C
respectively.
-Sterilizing hormones, proteins, various heat sensitive drugs etc.
-Demerits: These gases are potentially mutagenic & carcinogenic. They
also produce acute toxicity including irritation of the skin, conjunctiva and
nasal mucosa 13
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14. LIQUID STERILIZATION
 Peracetic acid is sporicidal at low concentrations.
 Merits: Water soluble & leaves no residue after rinsing. Has no
harmful health or environmental effects.
 MOA: Disrupts bonds in proteins and enzymes and may also
interfere with cell membrane transportation through the
rupture of cell walls and may oxidize essential enzymes and
impair vital biochemical pathways.
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15. RECENT ADVANCES IN STERILIZATION
 Sterilization, as a specific discipline, has been with us for
approximately 120 years, since the invention of the steam autoclave
by Charles Chamberland in 1879
 We have seen progressive refinement in steam sterilizers: from the
early, manually operated equipment to modern microprocessor-
controlled, automatic machines.
 Although the efficiency, reliability, and performance monitoring of
modern equipment is continually improving, the fundamental
process remains essentially the same.
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16. NEW STERILISATION METHODS
Chemical methods Physical methods Physicochemical
methods
Synergistic methods
-Surfacine -Pulsed light
sterilization
-Gas plasma
sterilization
-Psoralen and UVA
-Superoxidized
water
-Ultra high pressure
sterilization
-Ultrasound and
bactericide
-Chlorine dioxide -Hydroclave
-Glutaraldehye
-Ortho
phthalaldehyde
-Endoclens
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17. SURFACINE
 Surfacine is a surface coating that kills microorganism on
contact, by selectively delivering Silver.
 Used on animate or inanimate surfaces.
 Despite the fact that silver ions possess antimicrobial efficacy
equal to or greater than other heavy metals ions, but is almost
non toxic to mammals.
 Silver has a broad spectrum of activity (bacteria, yeast and fungi)
CHEMICAL METHODS OF STERILIZATION
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18. Mechanism of SURFACINE
 It incorporates silver iodide in a surface-immobilized coating
(a modified polyhexamethylenebiguanide) that is capable
of chemical recognition and interaction with the lipid
bilayer of the bacterial cell membrane by electrostatic
attraction.
 The intimate microbial contact with the surface results in
transfer of silver directly from the coating to the organism.
 Microorganisms contacting the coating accumulate silver
until the toxicity threshold is exceeded; dead
microorganisms eventually lyse and detach from the surface.
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19.  A 3-D polymeric network is immobilized onto the
substrate surface
 The immobilized surface network is impregnated
with sub-micron particles of silver iodide that
result in the formation of AgCl-polymer complex
 Solubility characteristics of this complex prevent
ionic silver from leaching into solutions contacting
the surface coating
 Silver is available, however, to react with
bacterial cells contacting the coating
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20.  Silver is preferentially transferred directly to
the microorganism causing a toxic accumulation
that results in cell death.
 The silver halide reservoir within the polymeric
network replenishes the coating surface with
silver, allowing the coating to maintain high
surface anti microbial activity to microorganisms
that contact it for further challenges
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21. Advantages
 Very low leaching of silver into solutions
 Duration of activity: Long term
 Reservoir capacity: High
 Non toxic to humans
Disadvantage
 Not active against viruses and very less activity against spores.
Applications:
Can be used in:
 Medical devices: prostheses, catheters, endotracheal tubes etc
 Dental care products
 Food preparation & packaging
 Water storage, treatment and delivery systems 21
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22. SUPEROXIDIZED WATER (STERILOX/MEDILOX)
 Broad spectrum disinfectant, introduced recently.
 Prepared by electrolyzing saline solution with titanium-
coated electrodes at 9 amp
 The main products are Hypochlorous acid[HClO] as
well as free chlorine radicals & superoxide radicals
 The product generated has a pH of 5.0-6.5 and an redox
potential of >950 mV.
 MOA is not clear but probably relates to a mixture of
oxidizing species.
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23. Applications:
 Freshly generated superoxidized water is rapidly effective (<2
minutes) against microorganisms (Mycobacterium tuberculosis, M.
chelonae, poliovirus, HIV, MRSA, E.coli, Candida
albicans, Enterococcus faecalis, Pseudomonas aeruginosa)
Advantages:
 Basic materials i.e saline and electricity, are cheap & the end product
(water) is not damaging to the environment.
 Nontoxic to Humans
 Noncorrosive and nondamaging to endoscopes
Disadvantage:
 Equipment used to produce the product may be expensive because
parameters such as pH, current, and redox potential must be closely
monitored. 23
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24. CHLORINE DIOXIDE(ClO2)
 Prepared by reacting Hypochlorus acid and sodium or potassium
chlorate.
MOA
 It is a molecular free radical and disinfects by oxidation
 Organic materials in bacterial cells react with chlorine dioxide,
causing several cellular processes to be interrupted
 Chlorine dioxide reacts directly with amino acids and the RNA in the
cell ->proteins synthesis is blocked-> cell death
 Application:
-Drinking water disinfection
-Can be used against anthrax (ClO2 is effective against spore forming
bacteria)
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25. Advantages:
 Alternative to chlorine- Better disinfectant activity than chlorine.
Deactivates chlorine resistant Giardia and Cryptosporidium
 No odour nuisance, unlike chlorine.
 Unlike chlorine, prevents formation of harmful halogenated
disinfection by-products.
 Low contact time required.
Disadvantages:
 Explosive
 Safety equipment must be used while handling as it causes irritation,
watery eyes
 Highly unstable when in contact with sunlight.
 More expensive than chlorine. 25
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26. GLUTARALDEHYDE
 Trade names: Cidex, Sonacide, Sporicidin, Hospex.
 Cold sterilant- used to sterilize a variety of heat sensitive instruments
viz. endoscopes, bronchoscopes, dialysis equipment, anesthesia &
respiratory equipment, transducers & spirometry apparatus
 Concentration: 2-3% -is active against a wide range of microorganisms:
Gram positive & negative, mycobacteria & spores
MOA:
 Causes Alkylation of sulfhydryl, hydroxyl, carboxyl, and amino groups of
microorganisms ->alters RNA, DNA, and protein synthesis.
 Aqueous solution of glutaraldehyde is not sporicidal. Only when it is
activated(made alkaline) using alkylating agents (pH 7.5-8.5) does the
solution become sporicidal.
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27. Spectrum of activity:
 Active against MRSA(methicillin resistant Staphylococcus aureus),
VRE(vancomycin resistant enterococci), Influenza A virus, E.coli,
Salmonella typhi, P.aeruginosa, Klebsiella, Avian rotavirus.
 Inactive against Mycobacterium chelonae, M.avium-intracelulare,
M.xenopi, fungal ascospores, Cryptosporidium
Engineering controls:
 The goal of engineering controls is to keep the vapours from
entering the work room & the employee’s breathing zone by
containing & removing at the source of release.
 General room ventilation
 Local exhaust hoods
 Transfer procedures 27
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28. Use and handling:
 While transferring, pour the liquids carefully and minimize
splashing and agitation
 Rinse soaked instruments under running water.
 Use adequate ventilation
 Use protective equipments: Gloves, Glasses, gas masks, etc
Transportation and storage:
 Should be done in closed containers wih tight fitting lids to
minimize potential for spills
 Store in a cool, secured and properly labelled area
 Dispose off outdated solutions properly
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29. Advantages:
 Biodegradable
 Non carcinogenic (unlike formaldehyde)
 Non corrosive to metals, rubbers, plastics
 Relatively inexpensive
 Excellent material compatibility
Disadvantages:
 Side effects due to glutaraldehyde vapours: Respiratory and dermal
irritant, occupational asthma, itching of eyes, rhinitis.
 Pungent & irritating odour
 Slower mycobacterial activity as compared to OPA
 Exposure to vapours should be monitored
 Protective equipment to be used during handling and transfer of gas.29
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30. ORTHO-PHTHALDEHYDE(OPA)
OPA received clearance by FDA in Oct. 1999.
MOA – similar to glutaraldehyde
Advantages:
Potential advantages compared with glutaraldehyde:
 Active against glutaraldehyde resistant Mycobacterium
 Non-irritant to the eyes and nasal passages
 Has excellent stability over a wide range of pH (pH 3-9)
 Does not require exposure monitoring, and has a barely perceptible
odour.
 Like glutaraldehyde, OPA has excellent material compatibility.
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31. Disadvantages:
 OPA stains proteins gray (including unprotected skin) and
thus must be handled with caution (i.e., use of gloves, eye
protection, fluid-resistant gowns when handling contaminated
instruments, contaminated equipment, and chemicals).
 Limited clinical studies of OPA are available.
Disposal:
 If OPA disposal in the sanitary sewer is restricted, glycine
(25 g/gallon) can be used to neutralize the OPA and make
it safe for disposal.
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32. ENDOCLENS
 Used for sterilization of flexible endoscopes
 Consists of a computer-controlled endoscope-
reprocessing machine that uses performic acid as
a sterilant. The sterilant is produced by automatic
mixing of the two component solutions of
hydrogen peroxide and formic acid
The system's major features are:
 an automatic cleaning process
 capability to process two flexible scopes asynchronously
 filter water rinsing and scope drying after sterilization
 hard-copy documentation of key process parameters
 user-friendly machine interface
 total cycle time (scope testing, washing, sterilization,
and drying) is less than 30 minutes.
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33. PHYSICAL METHODS OF STERILIZATION
PULSED LIGHT STERILIZATION
 It is a nonthermal method for sterilization that involves the use of
intense, short duration pulses of a broad spectrum to ensure
microbial decontamination.
MOA:
 It appears that both the visible and infrared regions, combined
with the high peak power of pulsed light, contribute to killing
microorganisms.
 Various mechanisms have been proposed to explain the lethal
effect of pulsed light, all of them related to the UV part of the
spectrum and its photochemical and(or) photo-thermal effect.33
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34. Photo chemical mechanism
 Primary target of pulsed light is nucleic acids because DNA is a target
molecule for these UV wavelengths.
 The germicidal effect of UV light has been attributed primarily to a
photo-chemical transformation of pyrimidine bases in the DNA of
bacteria ,viruses ,and other pathogens to form dimers.
 Formation of such bonds prevents DNA unzipping for replication & the
organism becomes incapable of reproduction. Without sufficient repair
mechanisms , such damage results in mutations, impaired replication
and genetranscription, and ultimately the death of the organism.
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35. Photo thermal mechanism:
 The lethal action of pulsed light also can be due to a photothermal effect.
Disinfection is achieved through bacterial disruption during their temporary
over heating resulting from the absorption of all UV light from a flashlamp.
 This over heating can be attributed to a difference in UV light absorption
by bacteria and that of a surrounding medium.
 The water content of bacteria is vaporized, that induces membrane
disruption.
Types of damage induced by pulsed UV light are:
 Photolysis
 Loss of colony-forming ability
 Inability to support phage growth (enzyme inactivation)
 Destruction of nucleic acid. 35
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36. CLARANOR STERILIZATION EQUIPMENT:
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37. Operation:
The pulse is produced in 2 steps:
 1. A 20 kV pulse lasting a few nanoseconds makes the xenon-filled
lamp conductive while creating an electric arc in the lamp
 2. The capacitor charged at 3000 V discharges in this arc during a
300 microsecond pulse, which ionizes the gas in the lamp and
generates a plasma emitting a very high intensity white light
(20,000 times greater than sunlight on the earth's surface)
 The energy of the lamp, which is delivered over a very short period
(0.3 ms), produces a power of 1 MW, half of which is dissipated in
heat and the other half in optical energy.
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38. Advantages:
 Total DNA destruction
 Quick process
 No chemicals used.
 Worker-friendly (safe and easy to use)
 Minimum space requirements.
 Water circulated for cooling of lamps can be recycled.
Disadvantages:
 Pulsed light is a surface treatment. The decontaminated areas are those
which receive the light pulse
Applications:
 Sterilization of caps, cups, lids and other packaging materials
 Sterilization of food packaging
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39. HYDROCLAVE
 The Hydroclave is essentially a double-walled
(jacketed) cylindrical, pressurized vessel,
horizontally mounted, with one or more side or top
loading doors, and a smaller unloading door at the
bottom.
CHARACTERISTICS:
 Sterilizes the waste utilizing steam, similar to an
autoclave, but with much faster & much more even
heat penetration
 Hydrolyses the organic components of the waste such
as pathological material.
 Removes the water content (dehydrates) the waste.
 Breaks up the waste into small pieces of fragmented
material.
 Reduces the waste substantially in weight and volume
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40. STEPS INVOLVED IN THE TREATMENT CYCLE
a) Loading
b) Heat-up and fragmentation
c) Sterilization period
d) De-pressurization and De-hydration
e) Unloading
a) Loading
 In smaller units, materials to be sterilized are packed &
loaded manually
 In large sized units, a combination of conveyors, hoppers
and tippers are available to load the waste into large top
loading doors. 40
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41. b) Heat-up and fragmentation
 After loading, the vessel doors are closed, and the outer jacket of
the vessel is filled with high temperature steam, which acts as an
indirect heating medium for heating the waste
 During heat-up, the shaft and mixing arms rotate, causing the
waste to be fragmented & continuously tumbled against the hot
vessel walls.
 The moisture content of the waste will turn to steam & the vessel
will start to pressurize.
 At the end of this period, the correct sterilization temperature and
pressure are reached, and the sterilization period is initiated
automatically
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42. c) Sterilization period
 By computer, the temperature & pressure are maintained
for the desired time to achieve sterilization.
 The mixing/fragmenting arms continue to rotate during
the entire sterilization period, to ensure thorough heat
penetration into each waste particle.
 Sterilization time of 15 minutes at 132 C, or 30 minutes at 121 C
d) De-pressurization and De-hydration
 After sterilization period ends, the vessel is de-pressurized via a
steam condenser, which causes initial waste dehydration due to
depressurization.
 The steam to the jacket will remain on, agitation continues, and the
waste loses its remaining water content through a combination of
heat input from the jacket and continued agitation.
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43. e) Unloading
 Due to the unique construction of the mixing arms, the opposite rotation
causes the fragmented waste to be pushed out of the vessel discharge
door, into a waste container, or onto a conveyor.
 The vessel is now ready for another treatment cycle, having retained most
of its heat for the treatment of the next batch.
Uses:
The Hydroclave can sterilize:
 Bagged waste, in ordinary bags
 Sharps containers and needles
 Liquid containers
 Cardboard containers
 Metal objects
 Plastics
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44. Advantages:
 Performance
 Guaranteed high level of sterilization, including wet waste, metals,
liquids and sharps.
 Automatic operation, and not dependent on operator skill for sterility.
 No infectious or harmful emissions.
 Economic
 Low operating cost with low energy consumption.
 Low maintenance costs.
 No costly bags, filters or chemicals in the process.
 Very large weight and volume reduction of the waste.
 Dry waste, regardless of its original water content.
 Low odour, due to the dryness. 44
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45. Hydroclave Autoclave
•Low operating cost by recycling
steam.
•No special bags required
•Treats wet or liquid loads easily
•Strong weight reduction
•Strong volume reduction
•Consistent high sterility
•Higher operating cost, no steam
recycling
•High temp. bags required
•Cannot treat wet or liquid loads
•Weight increase
•No volume reduction
•Spotty sterility
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46.  Also called High hydrostatic pressure sterilization(HHP)/
Pascalization. Mainly used in food sterilization technology
 It is a cold sterilization technique by which products, already sealed
in its final package, are introduced into a vessel and subjected to a
high level of isostatic pressure (200–600MPa/43,500-87,000psi)
transmitted by water, for few seconds to few minutes.
 Pressures > 400 MPa at cold
(+ 4ºC to 10ºC)inactivate vegetative
flora(bacteria, virus, yeasts, moulds
& parasites) present in food,
extending its shelf life
ULRA HIGH PRESSURE (UHP) STERILIZATION
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47. MOA:
• Under UHP the volume of the pdt is compressed, results in the deeper
penetration of proteins & other macromolecules into the pdt,
resulting in the destruction of its 3-D structure
• Thus the food's proteins are denatured, hydrogen bonds are fortified,
& noncovalent bonds in the food are disrupted, while the product's
main structure remains intact -> causes starch and protein
denaturation and enzyme inactivation, all of which may have an
effect on the texture of the product. Pressure is instantly and evenly
applied to the product, regardless of its size, shape and volume.
• Because UHP sterilization is not heat-based, covalent bonds are not
affected, causing no change in the food's taste
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48. Advantages:
 Being a cold sterilization the characteristics of the fresh product are
retained, nutritional properties, flavor and taste remain almost intact.
 Destroys pathogens (Listeria, Salmonella, Vibrio, Norovirus, etc.)
 Extends product shelf life: improved customer satisfaction.
 Avoids or reduces the need for food preservatives: Clean label foods
(Natural/Additive Free).
 Only needs water (which is recycled) & lower electricity consumption:
Environment friendly.
Disadvantages:
 For the inactivation of bacterial endospores require synergistic action
of very high pressure(>600MPa) & temperature(>60*C)
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49. PHYSICOCHEMICAL METHODS OF STERILIZATION
GAS PLASMA STERILIZATION
 Discovered by Sir William Crookes in 1879. This technology was
patented in 1987 and marketed in U.S in 1993
 Plasma is defined as an ionized gas with an equal no. of +ve & -ve
ions. 4th state of matter. Its properties are similar to those of both
gases and liquids.
 Gas plasma is generated in an enclosed
chamber under deep vacuum (low pressure)
using radiowaves or microwaves to excite
gas molecules (hydrogen peroxide) to
produce ionized gas particles 49
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50.  MOA: It operates synergistically via three mechanisms:
1. Free radicals interactions
2. UV/VUV radiative effects
3. Volatilization
 UV/VUV radiation causes
-Formation of thymine dimers in DNA, inhibiting bacterial
replication.
-Base damage
-Strand breaks
 Volatilization: It is able to vaporize microbiological matter,
causing physical destruction of spores.
Application: STERRAD System enable sterilization of surgical instruments,
rigid and flexible endoscopes, cameras, catheters,etc.
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51. Steps involved in plasma steriliztion:
 1. The Vacuum Phase: Internal pressure is reduced by evacuating the chamber
 2. The Injection Phase:
Liquid peroxide is injected into the chamber, evaporating the aqueous hydrogen
peroxide solution & dispersing it into the chamber, where it kills bacteria on any surface
it can reach
 3. Diffusion phase:
The H202 vapor permeates the chamber, exposing all load surfaces to the Sterilant and
rapidly sterilizes devices and materials without leaving any toxic residues
 4. The Plasma Phase
An electromagnetic field is created in which the H2O2 vapour breaks apart, producing a
low-temperature plasma cloud that contains ultraviolet light and free radicals.
 5. The Vent Phase
The chamber is vented to equalize the pressure enabling the chamber door to be opened.
There is no need for aeration or cool-down. Devices are ready for immediate use.
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52. Advantages:
 The process is usually at room temperature and hence poses no dangers
associated with high temperatures (unlike autoclaves)
 Byproducts are generally water and oxygen-harmless to the environment
 Time of treatment is fast(1 min or less)
Disadvantages:
 Weak penetrating power of the plasma. Complications arise in:
-Presence of organic residue
-Packaging material
-Complex geometries
-Bulk sterilization of many devices
 High power consumption
 Can corrode certain materials
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53. SYNERGISTIC STERILIZATION METHODS
PUVA (Psoralen and UVA)
 Psoralen is a coumarin derivative which occurs naturally in the seeds
of Psoralea corylifolia, as well as in the common fig, celery, parsley
and in all citrus fruits
 MOA: Psoralen intercalates into DNA and on exposure to ultraviolet
(UVA) radiation can form monoadducts and covalent interstrand
cross-links (ICL) with thymine, resulting in apoptosis.
Uses:
 -Sterilization of Blood plasma and platelets
 -It is also active against viruses ex.HIV, hepatits, etc
 -Other uses of PUVA: Treatment of psoriasis, eczema, vitiligo53
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54. ULTRASOUND AND BACTERICIDE:
 Low(20kHz) or High(250kHz) frequency ultrasound energy is
synergistic with low concentration Glutaraldehyde
 This technique is effective in killing bacterial endospores.
Advantages:
 -Heat sensitive materials can be sterilized(plastics and rubber
equipments)
 -Inexpensive and quick sterilization is possible.
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55. CONCLUSION
 We have seen the new methods used in sterilization, which have
been developed in the past few decades and currently in use in
the industries for sterilizing medical instruments, foods and
pharmaceuticals.
 Most of these methods are automated and efficient, environment
friendly, have low running cost, can sterilize on a large scale,
highly effective against certain resistant microorganisms and
ensure complete sterility of products.
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56. REFERENCE
 The theory and practice of industrial pharmacy by Lachman and Lieberman
 Gas Plasma Sterilization in Microbiology: Theory, Applications, Pitfalls and New Perspectives by
Hideharu Shintani, Akikazu Sakudo
 Disinfection, sterilization and preservation by Seymour Stanton
 Hospital sterilization by Anand Nagaraja Prem
 www.Medscape.com
 www.mddionline.com
Thank You….56
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