Justification of conditions of salicylic acid introduction into emulsion ointment base composition

Abstract

Introduction. The revival of extemporaneous production requires the updating of prescriptions, the improvement of the technology of drugs, the study of stability in the process of storage in order to extend the shelf life. Semi-solid dosage forms, which take more than 25 % of medicines prepared in pharmacies about the stock, are currently prepared on a vaseline base. It has many disadvantages compared to the modern emulsion bases that are widely used in European practice. Therefore, the creation and implementation of modern emulsion bases for semi-soled dosage forms is a promising direction for the development of pharmaceutical compouding. To obtain the drug of good quality, it is necessary to provide a rational way of introducing the active substances to the base, so it is necessary to justify the parameters of the ointment with salicylic acid preparation in the conditions of pharmacies.  Material & methods The samples of the emulsion bases of the first and second kinds, into the composition of which 20 % of salicylic acid was introsuced by the different technology, were investigated. Determination of the degree of dispersion of the oil phase and salicylic acid in the base was carried out using a “NIKON ECLIPSE CI-S” triocular digital usb microscope with a built-in camera (the lens 40 X / 0.65 160 / 0.17; eyepiece WD 0,56) with 40x magnification. Results & discussion  Microscopic imaging of the test samples showed that the average size of crystals in the base of the first kind was 5 times larger than in the base of the second kind. A more uniform distribution of the drug substance in the sample with the base of the second kind was established. It is shown that the more complete dissolution and uniform distribution of salicylic acid in the base are observed when dissolving the drug substance in the emulsion base of the seconf kind. Conclusion. Physico-chemical and microscopic studies substantiated the method of introducing salicylic acid into the emulsion base. The dependence of the degree of dispersion and distribution of salicylic acid on the type of selected emulsion base is shown. It was shown that API is advisable to dissolve in oil, since it promotes less dispersion and a more homogeneous distribution of salicylic acid. The technological scheme of preparation of 20 % salicylic ointment in the conditions of pharmacy is developed, which is layed in the basis of the technological instruction.

DOI: 10.5281/zenodo.3885073