Problem with Modern Antibiotics

Let us start with a little bit of the background on the problems involving the use of modern antibiotics.

First one into the list will be Antimicrobial Resistance. Years after years into using, for example, alcohol-based disinfectants have caused bacteria to evolve resistance and this is a worrying phenomenon worldwide because drug-resistant bacteria can spread at an unprecedented rate and cause infections that are much more difficult to treat. And then, some of those antibiotics are actually carcinogenic, rendering them unsafe for many applications.

Then we have those organic-based substances, which might work well in certain areas but they decompose at high temperature, making their use in say, polymer processing a big challenge. Metal oxides compound do not have this problem, but they rely on external stimuli, such as UV, to generate Reactive Oxygen Species, limiting their practical use in general.

We also have other problems such as being unnatural, where the use of a certain product may negatively impact the ecosystem, or they just simply don’t work long enough, like alcohol, they’re effective but they vaporize too quickly. And that’s still not mentioning the fact that it is hard to find a product that is effective against a wide spectrum of bacteria species.

Antimicrobial Technology

This is defined as a substance that works to inhibit the growth and reproduction of all or some of  microbes ie bacteria and fungus like molds and mildews

Unlike alcohol which has a limited residue once the treated surface dries an antimicrobial technology substance works to continuously minimise the presence of microbes throughout the life of the product.

What is an Antimicrobial Additive

It is a powder or liquid or pellet that contains an appropriate amount of antimicrobial agent integrated at stage of manufacture or processing to be able to provide continuous antimicrobial protection for the product over its usage time.

Antimicrobial Additives classifications and their properties.

Antimicrobial Additives are either Organic(chemically synthesised) or Inorganic(natural metals or compounds of metals)

Competitive Advantages of Rozinco

Organic Additives:

i. Arsenic Based

Oxybisphenoxarsine(OBPA)

Often used in plastics, shower curtains, industrial parts to prevent bacterial and fungal growth.

Disadvantages:
1. Highly corrosive and toxic.
2. A chemical used popular in 1960s but not so much currently due to toxicity concerns as it contains arsenic and pollutes the environment.

Advantages:
1. Cheap
2. Available in liquid and powder form so easier in applications as a binder or carrier in not needed.

ii. Phenols

Synthesised from petroleum industry e.g. phenol is a derivative from benzene. This is also called carbolic acid.

Chemically synthesised Phenols in common use:
• Chloroxylenol
• Hexachlorophene
• Triclosan
• Widely used in cosmetics, consumer products like body and hand wash, toothpaste.

Disadvantages:
1. In concentration it is toxic
2. Corrosive to skin and mucous membranes
3. Many are banned as cosmetic ingredient for either preservative or antibacterial usage.
4. Can trigger allergies in mammals including human
5. Very toxic to fish and cats
6. Effective antibacterial against gram positive bacteria S. aureus but weak against gram negative like E.coli and P. aeruginosa.
7. Some like Triclosan suspected to trigger DNA mutation and mammals and now banned by FDA for many applications. It is a suspected carcinogen.
8. Hexachlorophene (famous for acne wash Phisohex).
9. FDA has warned against using baths with more than 3% of hexachlorophene as it is suspected that absorption by skin can lead to brain and nerve damages.(Toxic in even low concentrations)
10. The antimicrobial agents are consumed as they are used up killing bacteria. For continued efficacy, it requires topping up of antimicrobial agents.

iii. Quaternary Ammonium Compounds(Quats)

Benzalkonium Chloride (BAK)
Benzethonium Chloride
Benzyltrimethylammoniun fluoride

• BAK is usually used in skin creams for antibacterial effects and as preservative.
• It is also used in non-alcohol wipes and towels.
• Also widely used as surface cleaners, in bath and shampoos mixes. Even in baby care products.

Disadvantages:
1. It is a skin irritant and commercial products cannot exceed 0.1%.
2. It is also toxic in higher concentrations.
3. It is effective mostly with gram positive bacteria like S. aureus. And hardly any effect on gram negative bacteria like E.coli.
4. Encourage growth of  gram negative opportunistic bacteria like Pseudomonas.
5. Has varying efficacy on fungus and molds.
6. Forms films on surfaces applied.

Advantages:
1. Leaves no odour
2. Easily soluble

iv. Biguanides

PHMB or Polyhexamethylene biguanide or Polyhexanide or
Chlorhexidine

• Widely used topically in wound cleaning and disinfection(not exceeding 0.04% concentration)
• It has a surface active substance (surfactant) which helps penetrate biofilms of bacteria infection.
• It is effective on gram positive gram negative bacteria as well as fungus.
• It is used in contact lens cleaning, gargles and dental hygiene.
• It is used in swimming pool cleaning.

Disadvantages:
1. Toxic to fish and marine life.
2. Acute toxicity on human cells in relatively low concentrations.
3. Toxicity of use of PHMB in water treatment is under debate.
4. The Scientific Community for Consumer Safety(SCCS) has concluded that PHMB is not safe as a cosmetic or skin care ingredient at concentrations over 0.1%.
5. Many countries have banned PHMB in skin care products
6. Dr Shetler and Dr Falsetti have declared that evidence of animal and human studies show PHMB is carcinogenic(causes cancer) gene mutation and affects the reproductive system.
7. May cause skin irritation and chemical burns in premature infants.

a)Inorganic Additives

i.Titanium Dioxide
· It is extensively used in surface and paint coatings, food contact and packaging surfaces.
· Low toxicity and stable.
· Effective against gram positive and gram negative bacteria.
· Considered USFDA as GRAS(Generally  Recognised as safe) in food is amounts are less than 0.5%, and usable in candies and dairy products.
· It kills bacteria on contact by generating free radicals so does not lead to antibiotic resistance in mass use like silver.
· Useful for mixing in polymers for textiles and sputtering on surfaces.

Disadvantages:
1. Require UV or sunlight to activate its antimicrobial properties.
2. Classified by International Agency for Research on Cancer(IARC) as a Group 2B carcinogen means possible may cause cancer to humans.
3. Rising Titanium Dioxide prices.

i.Silver

• Silver in the form of Nanosilver particles or silver ions have antibacterial effect. Silver ions are used directly in liquid suspensions. Silver oxide is a very weak antimicrobial and has limited commercial applications except in skin creams.
• Silver kills gram positive and gram negative bacteria also kill fungus.
• Silver is used in many products including toothbrushes, washing machines, bandages, medical devices, household water filters, cosmetics, toys, plastic appliance and textiles especially exercise shirts, socks and towels.
• The particle are between 1 to 100 nanometres compared to human hair at about 80,000 nanometres(80 microns)
• Silver is relatively non toxic except for causing argyria (turning a person purple blue)

· Disadvantages:
1. Most products use Nanosilver which is toxic to human cells when as these can easily be transdermal. Animal studies have demonstrated toxicity to liver, lung and kidney cells.
2. These nanoparticles are also toxic to aquatic life and may harm the environment.
3.The build-up of Nanosilver in the food web raises concerns.

• Nano Silver acts by emitting silver ions which penetrate bacteria and kill bacteria by interfering with the replication process and also prevent the manufacture of ATP(Adenosine Triphosphate) which is the food source of the bacteria thus starving and killing the bacteria.


• Silver kills gram positive and gram negative bacteria also kill fungus.
• Silver is used in many products including toothbrushes, washing machines, bandages, medical devices ,household water filters, cosmetics, toys, plastic appliance and textiles especially exercise shirts, socks and towels.
• The particle are between 1 to 100 nanometres compared to human hair at about 80,000 nanometres(80 microns)
• Silver is relatively non toxic except for causing argyria (turning a person purple blue)

·Disadvantages:
1.Most products use Nanosilver which is toxic to human cells when as these can easily be transdermal. Animal studies have demonstrated toxicity to liver, lung and kidney cells.
2.These nanoparticles are also toxic to aquatic life and may harm the environment.
3.The build-up of Nanosilver in the food web raises concerns.
•Nano Silver acts by emitting silver ions which penetrate bacteria and kill bacteria by interfering with the replication process and also prevent the manufacture of ATP(Adenosine Triphosphate) which is the food source of the bacteria thus starving and killing the bacteria.
4. This unfortunately allows bacteria to mutate and makes it harder for silver to enter the bacteria which also activates an efflux pump to expel silver that have entered the bacteria.
5. This creates antibiotic resistance in the long run.
6. Colloidal silver as an antimicrobial to be ingested is baseless.
7. Price of Nano silver is about US$ 200 to US$ 400 per Kilo.  This is US $0.30 per gram before manufacturing into final product.

• Zinc Oxide displays effective antimicrobial in Nano state.
• 1000 nanometers = 1 micrometre(micron)
• Ordinary Zinc Oxide  displays minimal antimicrobial efficacy.
• Zinc Oxide is safe and classified as a skin protectant.

Nano Zinc Oxide is used extensively in skin lotions and sunscreens, in plasters, wound bandage and in industrial uses including batteries.

Disadvantages
1. It is cheap compared to Nano silver but is not a strong antimicrobial
2. Nano Zinc is considered an environment risk in quantities.
3. In concentration Zinc Oxide may be toxic.