セラック 化学特性,用途語,生産方法
定義
本品は、ラックカイガラムシ Laccifer lacca の分泌物である。
解説
セラック，インド，タイ，ミャンマーが主産地。アルコールワニスの主原料。アルコールワニスは一般に速乾性であるが耐水，耐湿性に難点があり，白化しやすいため，近年あまり使用されていない。ほかに研磨剤，電気絶縁材などに使用される。
製造
ラック樹脂，天然樹脂の一つ。ラック虫がアカシヤ属の木に寄生して分泌した樹脂質を精製した橙黄色の固形物。
化粧品の成分用途
ヘアスタイリング剤、結合剤、皮膜形成剤
化学的特性
Shellac is a natural resin that may be obtained in a variety of colors
ranging from light yellow to dark red in the form of hard, brittle
flakes with or without wax, depending on the refining process; see
Sections 4 and 13. The different types of shellac include bleached
shellac, bleached dewaxed shellac, dewaxed and decolorized
shellac, dewaxed flake shellac, dewaxed orange shellac, dewaxed
shellac, orange shellac, purified shellac, refined bleached shellac,
regular bleached shellac, regular waxy shellac, wax-containing
shellac, and white shellac. The flakes may be crushed or milled to a
coarse or fine powder. Bleached shellac is supplied as a coarse offwhite
powder.
Shellac is tasteless and may have a faint odor. The typical odor of
shellac is the result of a complex fragrance system.
使用
Shellac is used in the preparation of cosmetic products such as mascara and acrylic nail products. It is also used in the formulation of aqueous-core capsules for riboflavin release.
定義
shellac: A hard resin produced as asecretion by a plant parasite, thesouth-east Asian lac insect Laciferlacca. It is used in sealing wax, varnish(French polish), and electrical insulators.
危険性
(Alcohol solution) Flammable, dangerous
fire risk.
応用例（製薬）
Shellac is widely used as a moisture barrier coating for tablets and
pellets due to its low water vapor and oxygen permeability. It has
usually been applied in the form of alcoholic or aqueous solutions
(pharmaceutical glazes). However, due to stability problems with
alcoholic shellac solutions, it has had limited use in the pharmaceutical
industry for modified-release or enteric coatings.
Shellac, particularly novel aqueous shellac solutions, is mainly
used in food products and nutritional supplements. Recent research
results indicate good application properties and chemical stability
of shellac films from aqueous shellac solutions. Aqueous
ammonium shellac solutions, based on dewaxed orange shellac,
do not show the problems exhibited by alcoholic shellac solutions
and are used as an enteric coating for pellets, tablets, soft and hard
gelatine capsules, primarily in nutritional supplements.
Shellac is a primary ingredient of pharmaceutical printing inks
for capsules and tablets, and can be applied as a 40% w/v alcoholic
solution. It has also been used to apply one or two sealing coats to
tablet cores to protect them from moisture before being film- or
sugar-coated.
Other applications of shellac are the coating or encapsulation of
powders or granules, e.g. in probiotics. Prior to the introduction of
film coating, a combination of shellac, cetostearyl alcohol and
stearic acid was used as an enteric coating. In cosmetics, shellac is
used in hairsprays, mascara and lipstick formulations. Aqueous
shellac solutions are also used for colonic drug delivery.
安全性
Shellac is used in oral pharmaceutical formulations, food products,
and cosmetics. It is generally regarded as an essentially nonirritant
and nontoxic material at the levels employed as an excipient.
貯蔵
After long periods of storage, shellac becomes less readily soluble in
alcohol, less fluid on heating, and darker in color.
Shellac should be stored in a well-closed container at temperatures
below 15°C. Wax-containing grades should be mixed before
use to ensure uniform distribution of the wax. Orange and dewaxed
orange shellac have a shelf-life of 1 to 2 years. The shelf-life of
bleached shellac is approximately 6 months.
不和合性
Shellac is chemically reactive with aqueous alkalis, organic bases,
alcohols, and agents that esterify carboxyl groups. Therefore,
shellac should be used with caution in the presence of such
compounds.
規制状況(Regulatory Status)
Accepted as a food additive in the USA, Europe, and Japan.
Included in the FDA Inactive Ingredients Database (oral capsules
and tablets). Included in nonparenteral medicines (oral tablets and
capsules, often in printing ink formulations) licensed in the UK.
Included in the Canadian List of Acceptable Non-medicinal
Ingredients.
セラック 上流と下流の製品情報
原材料
準備製品