Quick Search

PRODUCTS

NIPAGUARD BNPD

Nipaguard BNPD is used as preservative for the cosmetic industry.

CAS number:
52-51-7

Chemical name:
Bronopol; 1,3-Propanedio-l,2-Bromo-2-Nitro

INCI designation:
2-Bromo-2-Nitropropane-1,3-diol

Nipaguard BNPD is used in personal care products. 
Nipaguard BNPD acts as a preservative. 
Nipaguard BNPD shows good performance against both bacteria and fungi.

Product properties of Nipaguard BNPD:
Appearance:
White or almost white crystals or crystalline powder

Chemical and physical data of Nipaguard BNPD:
pH 1% w/v in water: 5.0 – 7.0
Melting point ca: 130 °C
Sulphated ash Not more than: 0.1%
Water content: 0.5% max
Bronopol content: 99.0 – 101.0%
Solubility oil: not miscible
Stability Light: stable

Uses of Nipaguard BNPD:
Nipaguard BNPD is a broad spectrum antimicrobial agent designed for preservation of a wide range of cosmetics and toiletries. 
Nipaguard BNPD is suitable for both rinse- off and leave- on formulations.
Bronopol has been safely used in Personal Care for more than 30 years.

Applications of Nipaguard BNPD:
Nipaguard BNPD is effective against bacteria, fungi and yeast.
The recommended use level of Nipaguard BNPD to preserve most product types is normally in the range of 0.02 - 0.1% based on the total weight of the finished product.

Cosmetics and leave-on products:
Adding 100ppm to 1000ppm (0.01% to 0.1%) Nipaguard BNPD to suncare creams, liquid colour cosmetics, lotions, lipsticks and eye make-up will provide effective long-term preservation. 
The most common use level is 200ppm (0.02%) and it is frequently used together with an appropriate fungicide such as parabens or Protectol DA.

Babycare Products:
Creams, lotions, toiletries and toothpastes are effectively preserved by 100ppm to 200ppm (0.01% to 0.02%) Nipaguard BNPD. 
Nipaguard BNPD can also be used in oral pharmaceuticals for children.

Toiletries:
Nipaguard BNPD can be used to preserve a wide range of formulation types. 
Common use levels are between 100ppm to 300ppm (0.01% to 0.03%). 
Nipaguard BNPD is especially suitable for shampoos, conditioners, bath and shower gels and other rinse-off product types.

Bulk Surfactants and other Raw Materials:
Nipaguard BNPD is suitable for the preservation of aqueous dilutions of key surfactants such as sodium lauryl ether sulphate, for supply or at in-situ holding tanks. 
Typical use concentrations are between 100ppm and 300ppm (0.01 to 0.03%)

Regulatory Status:
Nipaguard BNPD can be used up to a maximum concentration of 0.1 % in cosmetic product; formation of nitrosamines must be avoided, according to Annex VI, 76/768/EEC (Europe).
Nipaguard BNPD is not permitted for Japan.
Nipaguard BNPD is considered safe as used up to a maximum concentration of 0.1 % except under circumstances where its action with amines or amides can result in the formation of nitrosamines or nitrosamides by Cosmetic Ingredient Review (1980, 1984).

Incorporation:
Nipaguard BNPD is up to 28 % soluble in water, and miscible with many organic solvents (e.g. Phenoxyethanol, Propylene Glycol, Ethanol, Butylene Glycol), surfactants and emulsifiers, Nipaguard BNPD is easily incorporated into the materials to be preserved. 
Nipaguard BNPD is not stable at alkaline pH and high temperatures. 
When Nipaguard BNPD disintergrates, one of the by-products is nitrous-oxide (NO2) which has the potential to form nitrosamines when primary and secondary amines (Triethanolamine, Cocamide DEA, Coconut Diethanolamine, etc) are present.

Factors affecting stability:
The stability of Bronopol in a formulation is dependent upon three main factors, namely temperature, pH and the oxidising/ reducing capacity of the system.

Temperature:
The antibacterial activity of Bronopol is maintained over a wide temperature range, however, the chemical stability of Bronopol decreases with increasing temperature.
Bronopol is best incorporated at the final stage in any production process. 

This is obviously important for hot process products where Bronopol should be added after first cooling to below 40°C, ensuring no reheating occurs.
Best practice is achieved by adding Bronopol in the form of a 10 % solution, freshly prepared using cold water or by using one of the commercially available liquid concentrates. 

The method of application is either by open pouring or by metered pumping following the handling instructions outlined in the safety data sheet. 
Where products undergo forced cooling, care should be taken to add at the lowest temperature commensurate with effective mixing.

Product pH:
The antibacterial activity of Bronopol is maintained over a wide pH range, however, the chemical stability of Bronopol decreases as the formulation becomes more alkaline. 
In alkaline formulations, Bronopol can act as a useful labile preservative, however, it may not confer long term preservation to the system. 

In more acidic formulations, Bronopol will provide long term antibacterial action and facilitate a product shelf-life over at least 2 years, as shown in Table 1.
Bronopol should be added at the final stage in the production process, as recommended above, and direct contact with strongly alkaline materials should be avoided. 
Examples of such materials include NaOH, KOH and TEA frequently used as neutralizing agents for ingredients such as fatty acids and carbomer type gels.

Oxidising / Reducing Agents:
The efficacy and stability of Bronopol is not affected by the vast majority of cosmetic and toiletry ingredients, however, in common with many performance chemicals, strong oxidising and reducing agents should be avoided. 
Bronopol can tolerate strong oxidising agents, such as chlorine, only at low levels (5ppm) particularly in alkaline environments. 

During product manufacture, care should be taken to ensure that any plant cleaned using hypochlorite is wellflushed with purified water prior to use. 
Hydrogen peroxide at levels at or below 50ppm will not significantly degrade Bronopol over contact periods up to 24 hours, however, higher levels or prolonged contact should be avoided. 

Strong reducing agents such as sodium thiosulphate and sodium metabisulphite can cause the rapid breakdown of Bronopol as well as reducing its antibacterial efficacy. 
Thioglycollic acid and its salts, frequently used in depilatory and permanent waving preparations cause similar problems and should be avoided.

Compatibility:
Surfactant Compatibility:
Unlike a number of other biocidal ingredients, Bronopol is compatible with all classes of surfactant, anionic, non-ionic, cationic and amphoteric; it is also used extensively by many producers to preserve bulk surfactants in diluted form prior to use in cosmetic and toiletry products.
The compatibility of Bronopol with surfactants has been studied using both chemical and microbiological techniques. 

Solutions were prepared and stored for 12 weeks at 4°C, ambient (22- 25°C) and 40°C. 
The Bronopol content was measured chemically using HPLC and the microbiological activity was determined using an agar diffusion technique. 
The different surfactant types are shown below:

Type / Trade Name / Common Name
Nonionic / Nonidet LG C9-C11 / Alcohol ethoxylate
Nonionic / Synperonic BD100 / C13-C15 Alcohol- ethoxylate
Nonionic / Ethylan C40AH / Ethoxylated castor oil
Nonionic / Ethylan KEO / Nonyl phenol ethoxylate
Amphoteric / Amphosol CA / Alkyl amido Betaine
Anionic / Texapon ES 1/S / Sodium lauryl ether sulphate
Anionic / Maypon 4CT / Protein hydrolysate
Anionic / Bioterge AS40 / Sodium C14-C16 sulphonate

Nonionic Surfactants:
Results on the above materials showed no significant reduction in chemical stability or microbiological performance of Bronopol under the test conditions.

Anionic Surfactants:
Three anionics were tested and with one, the protein hydrolysate, there was evidence of some loss in the chemical stability of Bronopol - ~35% loss over 12 weeks at 40°C. 
However, the microbiological data showed only a 6% drop in efficacy compared with storage at 4°C.

Very occasionally, material provided by some surfactant suppliers will degrade Bronopol. 
This can usually be traced to an excess of reducing agent from the manufacturing processes or the alkalinity of the stock solution.

Amphoteric Surfactants:
The data on the amphoteric surfactant indicated that there was a slight drop (4 to 8%) in both the chemical stability and the microbiological performance of Bronopol, but only after 12 weeks and at the highest temperature (40°C).

Cationic Surfactants:
In other assays, Bronopol has been shown to be chemically and physically compatible with a wide range of cationic surfactants ranging from the simple dialkyldimethyl ammonium halide types through alkyl aryl ammonium halides to heterocyclic and polymeric quaternary compounds.
Similar compatibility has also been shown with quaternary phosphonium halides and quaternary sulphonium compounds.

Protein Compatibility:
The activity of Bronopol is generally unaffected by the presence of proteins. 
For example, 10% Ox serum and 10% milk solution have been shown not to affect the bacteriostatic activity of Bronopol against Pseudomonas aeruginosa. 

Problems can be encountered with proteins/polypeptides rich in the amino acid cysteine due to the reducing capacity of its sulphydryl grouping. 
Similarly, other ingredients such as cysteine hydrochloride and cysteine itself should be avoided.

Compatibility with Other Ingredients:
Other commonly used ingredients such as co-preservatives, sunscreens, humectants, emollients, pigments, colours and gelling agents are not known to cause a problem with either the activity or stability of Bronopol. 
The performance of these ingredients is not usually affected by the presence of Bronopol.

pH stability:
Nipaguard BNPD remains fully stable over a wide pH range from 4.0 - 8.0.

Temperature stability:
Nipaguard BNPD should be incorporated during the cooling stage of hot processes. 
The recommended maximum handling temperature is 60°C.

Storage instructions:
Nipaguard BNPD should be stored at temperatures within the range 4- 40°C. 
Containers containing Nipaguard BNPD should not be exposed to direct sunlight. 

Storage conditions should also be in conformance with applicable legal, fire and insurance regulations.
Further information on handling, storage and dispatch is given in the EC safety data sheet.

Microbial Activity:
Nipaguard BNPD has a broad spectrum of activity which includes the following common spoilage organisms.

Microorganisms / MIC (ppm):
Bacteria:
Pseudomonas aeruginosa: 50
Escherichia coli: 50
Proteus vulgaris: 50
Pseudomonas putida: 50
Stpahylococcus aureus: 50

Microorganisms / MIC (ppm):
Yeasts:
Candida albicans: 1000

Fungi:
Aspergillus niger: 2000
Pencillium mineoluteum: 1000
Fusarium solani: 1000
Geotrichum candidum: 1000

Advantages of Nipaguard BNPD:
Nipaguard BNPD shows good performance against both bacteria and fungi.

Other Applications of Nipaguard BNPD:
Skin care (Facial care, Facial cleansing, Body care, Baby care)
Decorative cosmetics/Make-up
Toiletries (Shower & Bath, Oral care...) > Shower & bath
Toiletries (Shower & Bath, Oral care...) > Antiperspirants & deodorants
Toiletries (Shower & Bath, Oral care...) > Depilatories & after depilation
Toiletries (Shower & Bath, Oral care...) > Shaving
Hair care (Shampoos, Conditioners & Styling)
Perfumes & fragrances
Sun care (Sun protection, After-sun & Self-tanning)
 

  • Share !
E-NEWSLETTER