Development of the composition and research of the equivalence of suppositories with diclofenac sodium by in vitro method using “Dissolution” test for lipophilic solid dosage forms

The aim: Development of the composition and investigation of the equivalence of suppositories with sodium diclofenac by in vitro method on a device with a flow-through cell in accordance with modern requirements of SPhU. Materials and methods: The development of the suppository composition was carried out with the use of the substance of diclofenac sodium and the excipient of solid fat of various grades. Studies of the active ingredient release in vitro in comparison with the reference listed drug were carried out on a device with a flow-through cell according to the monograph SPhU 2.9.42. Results: The investigations of the physical-chemical properties of the diclofenac sodium substance (micronisation, solubility) and the basis of the solid fat carrier, which affect the release of the active ingredient from the drug formulation were carried. The "particle size" figure for 2 samples of the active ingredient was from 100 μm to 400 μm and not more than 15 μm, respectively. The optimal composition of suppositories was developed by the method of 2-factor experiments. The conditions for the "Dissolution" test were determined: the volume of the medium (720 ml), the dissolution temperature (37.0 ± 0.5) ºC, the time taken for sampling (15, 30, 45, 60, 90 min), the dissolution medium – buffered solution with a pH of 7.4. The calculated similarity factor f2 was 67, which indicates the similarity of the release profiles and the equivalence of the researched drug. Conclusions The pharmaco-technological properties of sodium diclofenac and the solid fat auxiliary substance were studied. A method for the release of sodium diclofenac with the use of a device with a flow-through cell in accordance with the requirements of the SPhU is developed. The level of release of sodium diclofenac in the dissolution medium from rectal suppositories was determined by the experimental method, as the first step in the bioavailability determination. The equivalence of the tested samples of suppositories with the reference listed drug with the help of the method in vitro was established