Q: I am making an oily gel with Sucragel and Sucrablend which I have to heat for the Sucrablend to dissolve. Do I also need to heat the oil phase?
A: Unless you have any solid ingredients in the oil phase, this phase can remain cold even if the Sucragel phase is heated.
Q: My manufacturing team and I have concerns about scale up as the process in the laboratory is very labour intensive. Do you have any advice for scale up?
A: Yes. We have a scale up guide to assist your manufacturing team. Scaling up is actually simpler and less labour intensive than the lab trials as more oil can be added at once as the stirring speed and size are much faster and bigger than a propeller stirrer in the lab.
Q : Can Sucragel be used to make wet wipes?
A: Yes. To make a lotion to be sprayed onto a wipe, simply dilute the Sucragel with water, add a small amount of a stabiliser and preserve. Alternatively, if you want additional oils in your solution, stir these into the Sucragel and then dilute with water. It has the added benefit of allowing the lotion to be shipped as a ‘concentrate’ to be used when it’s needed.
Q : Can Sucragel be used to disperse fragrances?
A: Sucragel can be used to disperse up to 5% essential oils or fragrance. Slowly stir the fragrance into the Sucragel using a propeller stirrer. The mixture should thicken into a gel/paste which will easily disperse into your aqueous base. For a clearer product, Sucragel AP can be used at about 2.5% for every 0.1% fragrance to produce a clear or almost clear solution with water (different fragrances give different clarities). This works best with systems that do not contain terpenes.
Q: I’ve made a cream with Sucragel and it very quickly split. What went wrong?
A: It is likely that the pH dropped below 4.5 or in extreme cases above pH 8. Gels, creams and lotions made with Sucragel should be kept above pH 4.5 and below pH 8. Dropping below or above that boundary for even a short time, for example when buffering, will cause the emulsion to split.
Also, note that Sucragel only emulsifies the system, it will not add viscosity or stability to the water phase. Therefore it is important to add a rheology modifier to ensure the water phase is stabilised.
Q: I have been using Sucragel CF to make an oily gel but it is too expensive, can I switch to Sucragel AP?
A: Yes, you can switch to Sucragel AP, but you will need to take into account the following points:
- You can use 2/3rds the amount of AP than CF, (15% instead of 20% to gel oils)
- Because there isn’t any oil in the AP, you need to add the oil slightly slower at the beginning
- There is a small amount of food grade ethanol in Sucragel AP which is less than 1%. You will still need to use Sucrablend to ensure high temperature stability.
Q: I’ve made an oily gel but it is not transparent. What has happened and what can I do?
A: Clarity is achieved when the refractive indexes of each of the raw materials add up. If your gel is not transparent is likely that some water has been lost during manufacture. Add small amounts of water (drop by drop) until clarity is restored.
BUT ... it is essential not to add too much water as the water/glycerine balance is vital in creating a system that does not need preserving. Also there is the chance that the product will turn into an emulsion.
Q: How do I reduce the viscosity of the oily gel?
A: Sucragel is unusual as the less there is in the formulation, the thicker the product.
- So by increasing the amount of Sucragel or decreasing the amount of oil, you will reduce the viscosity of the gel.
- A second option is to replace some of the oil phase with glycerine, but this is a balancing act as more glycerine may affect the feel of the finished product. Alternatively, by adding water the viscosity will instantly drop but the gel will go cloudy.
Q: Can the product be rescued if too much oil is added?
A: Yes. Wait until the gel and the oil have separated. Remove the oil from the top and then begin stirring again and slowly re-introduce the oil.
Q: The oil isn’t mixing into the gel and as I add more the mixture thins and splits? What should I do?
A: This is almost always a symptom of the way the process is being managed, and can be solved by:
- Ensuring that a propeller stirrer is used, or one which stirs in a circular motion
- Ensuring the stirrer is immersed in the Sucragel and is on at a fast speed
- Initially, adding the oil very slowly in portions
- As the viscosity increases, increasing the stirrer speed and height. Remember, the gel cannot be over stirred
Q: Why do I need Sucragel? Why can’t I make the D-Phase system myself?
A: In short, you can make it yourself but experience has shown that even the very biggest companies do not like making these systems for a number of good reasons:
- The sucrose laurate requires high temperatures for up to 6 hours to dissolve
- A lot of foam and air bubbles are generated (best manufactured under vacuum)
- Stirring can be a problem (design of vessel)
- Mixing requires care over a long time (operator judgement). Post manufacture adjustment is sometimes necessary
How can I improve the stability of HIPEgel Aqua system ?
One way is to add more wax – we have found you need at least 1% of a wax, ideally 0.5% of a high melting point wax (over 60 degree C MP) and another 0.5% of a ‘plastic’ wax.
High melting point waxes: Sunflower wax, beeswax, Hydrogenated vegetable oil, Cetyl Palmitate
Flexible waxes/butter: Petroleum or Lanolin substitute Lanolin, Lanolin substitutes, Petroleum Jelly substitutes, Muru Muru Butter, Shea Butter etc.
Also, particulates works well to stabilise at both high and low temperatures.
Suitable particulates include: Zinc Oxide, Titanium Dioxide, Starches (non gelling), nylon, polymers, etc.
Is it possible to use 10% or more solids with HIPEgel Aqua or Oleo?
Powders such as starch, ZnO and TIO2 are good for stabilising HIPEgel formulations. Clays, may result in clumping as when used with HIPEgel Aqua as there in not enough oil to coat the powder. Using HIPEgel Oleo with clays, plant powders etc. should yield good results. Remember to avoid using anything acidic as with Sucragel.
How to scale-up formulations with HIPEgel Oleo ?
For HIPEgel Oleo, you can use exactly the same method as Sucragel for scale up. Be aware of the much smaller initial phase, however, and make sure it is adequately agitated in the mixer. The oil phase needs to be added slowly, at the same rate as with Sucragel.
Is HIPEgel Aqua compatible with anionic surface active ingredients ?
HIPEgel Aqua is extremely sensitive to any sort of surfactant/emulsifier that wants to make oil-in-water emulsions. This is described in the usage guidelines and includes any high HLB emulsifier above about 10.
Due to the delicate structure of the emulsion the oil-in-water emulsifier immediately wants to turn the small external oil phase into droplets, so the whole structure is lost. You might end up with an oil-in-water emulsion, but it will be a high-viscosity milk.
Can surfactants be added to a HIPEgel Oleo system?
As with Sucragel, we don't recommend using extra surfactants with this system. These are really designed to be gentle, mild, low-surfactant systems and adding extra, possibly harsh surfactants, goes against this philosophy! HIPEgel Oleo is a very low surfactant system that is not really for hard cleansing.
Could more than 1.5% water be added to HIPEgel Oleo?
As a rule, the internal phase must be above 74% to make it a HIPE. In reality it's best if it is greater than 80%. Water (including water based actives) and glycerine can be added at a level so that the total amount of HIPEgel Oleo + water + glycerine < 25%. This does allow for quite a lot of water, however, and stability may be compromised if the amount of external phase is too high as the structure is lost and the viscosity will drop.
If HIPEgel Oleo is used at 6% and glycerine at 5%, then this allows an extra 13% water. Despite this, we would not recommend going above 5%.
What is the pH range for the HIPEgels?
A pH between 4 and 9 should allow for stable formulations. High pH will lead to hydrolysis of the ester bond while low pH will lead to hydrolysis of the glycosidic bond.
Can you use Silicones with HIPEgel Aqua?
Yes. HIPEgel Aqua has been tested with Dimethicone 350cs (2%) and gave a nice texture. It does add quite a lot of viscosity to the formula though, so should be used sparingly (ideally less than 1%).
What is the maximum percentage of electrolytes that can be used with HIPEgel Aqua?
HIPEgel Aqua loves electrolytes, the more the better. At least 1% of a divalent electrolyte such as magnesium sulphate is best but others such as magnesium chloride, sodium chloride are fine. Up to 3% is fine, although the formulation may start to feel sticky.
What is the minimum % water you can add to the HIPEgel aqua
To form a HIPE, the aqueous phase (which includes anything water soluble, such as glycerine, salts, water soluble actives, etc.) must be greater than 74%. However, the best viscosity and stability is achieved at over 80% aqueous phase, which is what this system is designed to work with. We are looking into new ways of stabilising different water levels and we will have more information on this soon.
What is the maximum percentage of glycerine you can add to the HIPEgel Aqua?
Testing showed that low levels of glycerine (less than 3%) led to lower stability than high levels (greater than 7%). We feel the ideal is about 5% to gain the best texture and stability.
What is the maximum amount of oil that can be incorporated when using HIPEgel aqua?
It very much depends on the oil, but the total amount of HIPEgel Aqua and oil/butter/wax/any oily components must not exceed 13% as you lose the HIPE structure and the system will become unstable.
Can other glycols be used instead of glycerine with HIPEgels?
We only tried pentylene glycol (natural origin), and the creams formed were not stable.
Is an emulsion made with HIPEgel Aqua stable at below 0°C?
We have only tested the creams made with HIPEgel Aqua at fridge temperature (0-4°C) and they are very stable at this temperature.
When using HIPEgel Aqua, does increasing the speed of the mixer change the size of the water particles in the emulsion?
At the moment, the only way we can test the size of the particles is by electron microscope as they are below the size of a light microscope. We have measured the particles as approximately 300nm using an electron microscope for a standard cream. We have not noticed any difference in stability or texture when different methods of manufacture are used.