Research on the development of quality control methods for a solid soap for treating psoriasis

Abstract

Products in the form of soap are a relevant addition to the complex therapy of dermatological diseases, including
psoriasis. The skin affected by psoriasis requires “soft” care, so the use of a hygienic product that has a moisturizing
and exfoliating effect will have a positive impact on the course of the disease, complementing the effect of the main
therapeutic agents. In view of this, based on the results of previous studies, we have proposed three compositions
of solid soaps, for which it is advisable to conduct a study of the main quality indicators at this stage of development.
Aim. To develop the quality control methods for model samples of the solid soap obtained.
Materials and methods. The study materials were model samples of the solid soap containing palm kernel, coconut, avocado, almond, olive, castor oils, as well as citric, salicylic acid and lactobionic acid. The study of organoleptic
properties, solubility, as well as characteristics affecting the soap quality (pH, chlorides and other substances insoluble
in ethanol, hydroxides of free fatty acids or alkali metals, the fatty acid content), such parameters as “Acid number” and
“Iodine number” was carried out. The active ingredients were identified.
Results. The resulting soaps are solid to the touch, without deformations, cracks and mechanical inclusions, white
or slightly yellowish in color, odorless or with a peculiar smell. They are soluble in water and ethanol (96 %) and have
a pH in the range from of 6.5 to 8.5. When determining the content of chlorides and other substances insoluble in ethanol, the residue weight was not more than 0.15 g in all samples studied. When determining the content of hydroxides of free
fatty acids or alkali metals, no more than 0.8 ml of 0.1 M sodium hydroxide solution was used for titration. The content
of fatty acids was more than 40 %; the acid number was no more than 205; the iodine number was not less than 83.
The results of identification reactions were positive.
Conclusions. The results of the study indicate compliance with the requirements for the main quality indicators of
the solid soap samples proposed by us.