Closely related to these general requirements and technological requirements for bases, which should: show chemical and physical stability in the process of manufacture and storage of suppositories, easily molded and retain the necessary hardness during insertion, have the ability to emulsify the required amount of solutions, have a certain plasticity, viscosity, deformation time and structural and mechanical properties. These technological requirements are met by lipophilic, hydrophilic bases and their mixtures used in the pharmaceutical industry in different countries of the world. As lipophilic suppository bases State Pharmacopoeia USSR XI recommends using cocoa butter, its alloys with paraffin and hydro-genated fats, vegetable and animal fats, solid fat, lanol, alloys of fats with wax and solid paraffin. Currently, cocoa butter remains the official pharmacopoeial base in the pharmacopoeias of a number of countries. Lipophilic bases should meet the following requirements: quickly melt in the rectum, have a melting point not higher than 37 ° C, have sufficient hardness and a small difference between the melting and solidification temperatures, have sufficient viscosity, absorb liquids well, be stable during storage.

Due to the fact that the melting points of the base components fluctuate within a fairly wide range (hydrofat – from 28 to 37 ° C, paraffin – from 50 to 57 ° C, cocoa butter – from 30 to 34 ° C), the actual melting point of the resulting alloy may be slightly higher or lower than the specified temperature. In this case, paraffin or hydrofat is added to the base in the amounts necessary to bring the melting temperature of the mixture to the specified value. In this case, use the «table of additives». In addition to the required melting point, suppository base should also have appropriate structural and mechanical properties. They can be judged by the time of total deformation of the suppository prepared from this base. Determination of the time of full deformation is carried out at a temperature of 37 ° C on the device Kruvchinsky. In the composition of bases are often introduced surfactants, which not only improve the structural and mechanical properties, but also affect the kinetics of release and absorption of medecine. Hydrophilic suppository bases are mainly represented by polyethylene glycols (polyethylene oxides) – condensed polymers of ethylene oxide and water. Domestic industry produces polyethylene glycols differing in molecular weight: PEO-400, PEO-1500, PEO-2000, PEO-4000 and PEO-6000.