JPH0260642B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an ointment base containing a high concentration of silicone oil.

Silicone oil is pharmacologically non-irritating and non-sensitizing to the skin, causes minimal irritation to the mucous membranes and conjunctiva of the eye, and exhibits almost no toxicity when injected or ingested. In addition to these characteristics, it has excellent physical and chemical properties such as antifoaming properties, water repellency, coating properties, heat resistance, stability, and viscosity constancy. Attempts have been made to apply it to However, since this product is generally difficult to emulsify, it has the disadvantage of being susceptible to phase separation, and this disadvantage is particularly severe in products containing a high concentration of silicone oil.

One attempt to solve the above drawbacks and wrinkles, already
More than 10 years ago, a method for producing a highly concentrated silicone oil-containing external preparation was proposed in Japanese Patent Publication No. 45-2916. In this known invention, an oil base that is particularly compatible with silicone oil is selected as the silicone oil, the oil base and the silicone oil are dissolved, and hydrogen containing a water-soluble emulsifier is added to emulsify the base. However, in the above-mentioned published invention, the amount of emulsifier added to the oil layer and the water layer is 10 to 30% and 2 to 10%, respectively, based on the total amount.
are recommended (18% and 3% in Example 1,
8 to 5% in Example 2).If the amount of emulsifier is large in this way, it becomes difficult to use it as an external preparation.

However, surprisingly, oily bases, emulsifiers,
When aqueous silicone oil is added and emulsified to silicone oil that is not compatible with this, a stable emulsified state is not only obtained, but the amount of emulsifier is also 2 to 5% of the total amount.
It was discovered that a much smaller amount was required compared to the above-mentioned known method.

Incidentally, according to the catalog of methylphenylpolysiloxane (KF56 manufactured by Shin-Etsu Chemical), which is a silicone oil that is compatible with oil-based bases, this product has excellent compatibility with organic chemicals and is compatible with other silicone oils (KF96, KF92, KF69, KF99, KF961, KF965,
KF50, KF54, etc.), it is compatible with ethanol, cyclohexanol, carbitol (diethylene glycol, monoethyl ether), cellosolve, liquid paraffin, paraffin wax, fatty acids other than glacial acetic acid, and animal and vegetable oils at room temperature. , is known to also dissolve diethylene diglycol stearate and methyl phthalate.
This finding is unexpected. I imagine that with a base that is compatible with an oil-based base like KF56 above, the action and effectiveness of the emulsifier will decrease for some reason due to the compatibility with the oil-based base, and as a result, a large amount of emulsifier will be used. Although it is thought that the use of In any case, it is a fact that silicone oil, which has been considered difficult to emulsify up to now, can be stably emulsified with a relatively small amount of emulsifier by the means of the present invention, and this fact deserves special mention.

In the method of the present invention, an emulsifier is added to and dispersed in an oily base and a silicone oil that is incompatible therewith, and then an aqueous system is added to this dispersion system to effect emulsification. The temperature during emulsification is usually 70 to 80°C. If it is necessary to add flavoring, do so when the product temperature drops to 40-45°C.

When a wax such as paraffin wax is added, the wax crystallizes when the product temperature drops to about 40℃, so it is recommended to break the crystals and improve the consistency by passing them through a homogenizer after cooling. desirable.

In the present invention, oily bases include higher fatty acids such as palmitic acid and stearic acid, higher aliphatic alcohols such as cetanol and stearyl alcohol, liquid paraffin, ozokerite, ceresine wax, paraffin wax, microcrystalline wax, vaseline, carbonized squalene, etc. Hydrogen, fats and oils such as beef tallow, lard, almond oil, apocard oil, olive oil, cacao butter, sesame oil, menjitsu oil, castor oil, palm kernel oil, coconut oil, palm oil, wood wax, rattan oil, beeswax, spermaceti oil , lanolin, waxes such as candelilla wax and carnauba wax, and esters such as diethyl phthalate and dibutyl phthalate.

The appropriate amount of these to be used is 10 to 30% of the total amount.

Next, the emulsifier does not need to be particularly lipophilic or hydrophilic, but nonionic ones are preferable for use as external preparations. Specific examples include polyoxyethylene hydrogenated castor oil derivatives, polyoxyethylene sorbitan monostearate, and the like. A preferable addition amount is 2 to 5% based on the total amount.

The silicone oil used in the method of the present invention is one that is not compatible with the above-mentioned oily base, particularly liquid paraffin, paraffin wax, fatty acids other than glacial acetic acid, animal and vegetable oils, and the like. This material is commonly called methylpolyoxysan and has the general structural formula shown below.

(CH ₃ ) ₃ SiO [(CH ₃ ) ₂ SiO] _o Si (CH ₃ ) ₃ (however, n = 3 to 650) KF96, KF92, KF69, KF99,
Methylpolyoxyloxanes having poor compatibility with oily bases, such as KF961, KF965, KF50, KF54, are generally suitable for the purpose of the invention. The preferred amount of these silicone oils to be added is approximately 20 to 50% of the total amount.

Despite containing such a large amount of silicone oil, the ointment base obtained by the method of the present invention is extremely stable and shows no signs of aging even after being left at 40°C and 0°C for more than 6 months. No change occurs.

The ointment base according to the present invention can be used as it is as a cold cream or foundation cream or as a base thereof, but it is preferable that the ointment base further contains a bactericide, a steroid hormone, vitamins, an anti-inflammatory agent, an ultraviolet blocker, etc. Add this to make an ointment product.

The embodiments of the invention will be described below with reference to Examples, but these are, of course, illustrative and do not mean a limitation on the spirit of the invention.

Example 1 A silicone oil (KF96) 38.00% Polyethylene glycol stearate 0.67% Polyoxyethylene hydrogenated castor oil derivative 1.33% Stearic acid 3.00% Setanol 7.50% Sodium lauryl sulfate 0.50% B Propylene glycol 5.00% 1,3-butylene glycol 7.00 % Water 37.00% or more Heat each component A and B separately on a water bath to about 75°C, then gradually add B to A while stirring until cooled to complete emulsification. The obtained product is an O/W type smooth creamy product with beautiful gloss and excellent spreadability.

Example 2 A Silicone oil (KF96) 20.00% Polyoxyethylene cetyl ether 2.00% Sorbitan monostearate 2.00% Liquid paraffin 10.00% Setanol 4.00% Paraffin 7.50% B Glycerin 3.00% Water 51.50% The above A and B components are used as examples The mixture was emulsified in the same manner as in 1 to obtain an O/W type cream base. Similar to Example 1, this product was also excellent as an ointment base.

Claims (1)

[Claims] 1. Production of an ointment base containing a high concentration of silicone oil, which is characterized by dispersing silicone oil together with an oily base that is incompatible with the silicone oil using an emulsifier, and then adding water to the dispersion to complete the emulsification. Law.