Research of technological and physico-chemical properties of doxepin hydrochloride

Introduction. A professional approach to the development of a medicine and in particular the dosage form (DF) includes a comprehensive analysis of the active pharmaceutical ingredient (API) and excipients. Therefore, a detailed study of the technological and physico-chemical properties of a pharmaceutical substance is a fundamental step in the development of a drug, due to which it is possible to choose a suitable drug and predict the technological process based on the characteristics of the medicinal substance.

Aim. The aim of this work is to study the technological and physico-chemical characteristics of doxepin hydrochloride.

Materials and methods. Doxepin hydrochloride ((E)-3-(dibenzo[b,e]oxepin-11(6H)-ylidene)-N,N-dimethylpropan-1-amine hydrochloride) (experimental sample), scanning electron microscope JSM-6510LV (JEOL, Japan), vibrating sieve CISA RP 200N (CISA Cedaceria Industrial S.L., Spain), bulk density tester ERWEKA SVM 102 (ERWEKA GmbH, Germany), flowability tester ERWEKA GTL (ERWEKA GmbH, Germany), drying oven BINDER FD 115 (BINDER GmbH, Germany) were used as the material.

Results and discussion. In the course of a number of experiments, data were obtained on the nature of crystals, solubility, particle size distribution, flowability and bulk tapped density of the studied powder. As a result of the study of API, it was revealed that the substance has an average degree of compressibility, the powder does not have a flowability property due to high statics, which is typical for the confirmed crystal shape of the powder under study. The above technological characteristics of the API should be taken into account when choosing the optimal DF.

Conclusion. As a result of the experiments conducted in this article, it was found that API of doxepin hydrochloride is a white crystalline non-loose powder with an average bulk density and degree of compressibility. The strong static of the powder is explained by the shape of its crystals in the form of plates with a large area of contact with each other. The substance is freely soluble in water, alcohol and a solution of PEG-400 : water (1 : 2). The technological properties described above will not allow the development of a solid dosage form by direct pressing without the use of excipients that improve the initial technological characteristics of the medicinal substance. An alternative method of manufacturing technology may be the use of granulation, or the choice of a different DF (for example, a liquid dosage form).

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