[HelenB]

The following method is a cheap method to give you approx. drop points, just to give you an idea.

The drop point is the temperature at which the first drop of the melting
substance to be examined falls from the tip of the thermometer

The
apparatus, consists of a mercury thermometer, which covers the range of
0-110°C, a test tube, and when in use, it is fixed to the test tube, by means
of a stopper through which the thermometer passes.  The whole device is immersed in a beaker with
a capacity of about 0.25 L, filled with water. 
The bottom of the test tube, is placed about 50 mm from the bottom of
the beaker. A stirrer is used to ensure that the temperature of the water
remains uniform. Wrap around the bulb of the thermometer the substance to be
tested.  Fix the thermometer as suggested
above in the test tube.  Do not to get in
contact with the test tube wall.

Heat the
water-bath and when the temperature is at about 10 °C below the presumed drop
point, adjust the heating rate to about 1 °C/min. Note the temperature at the
fall of the first drop. The reading of temperature at the fall of the first
drop is regarded as the drop point of the substance. Carry out at least 3
determinations, each time with a fresh sample of the substance.  The difference between the readings, must not
exceed 3°C.  The mean of three readings
is the drop point of the substance.

[HelenB]

I agree with you, the wax ratio is off.  You must have a high melting point…more than 62 d Celsius.  Try to reduce your Ozokerite, which provides the hard and less flexible part of your formula.  I would use less than 2%.  Also, which grade of Microcrystalline cera do you use?  Do you know its melting point?.  When you end up with your correct, combination of waxes, (melting point, should not exceed 55degrees)  then try and play around with different ratios of your oils, to achieve good spreadability and sensorial properties

[HelenB]

Hi all, it was actually, a “natural” toothpaste suitable for homeopathy, with fennel essential oil &  with Calcium Carbonate…. (20 years back) and as the company I was working back then did not have appropriate equipment, I used a mortar & pestle.  I still remember the pain….

[HelenB]

Dear johnb, thank you, it sounds more complicated, than I thought

[HelenB]

Thank you very much for your replies.  The problem is that this is an inherited formula, that nobody really wants to change (it counts more than 10 yrs).  I will change it of course to achieve full integrity.

Also, by checking out Nivea’s cream, it seems, that they only use Decyl Oleate as an emulsifier, without any other fancy emulsifiers and it looks quite stable as well, with a similar sensorial feeling as our product.  Are you familiar, with any oily soluble polymeric thickeners, that could be used in this case?  I only can think of Bentone gels and increase in waxes, but the product will be sticky

Dear Bobzchemist, thank you for answering my shear “question”, I really, did not have a clue..why this happens .

I have to play around with the emulsifier system, any suggestions of the “correct” ratio of emulsifiers & oils?  I would like to keep it with the same INCI list.

Dear Bill_Toge, my next solution will be ex. Arlacel P135, thank you