AIM OF THE STUDY. The study on the effect of absorption promotors on the properties of hydrogels prepared from Carbopol 934P basis containing 1% hydrocortisone.
Materials: hydrocortysone, Carbopol 934P, propylene glycol-1,2 N,N-dimethylacetamide purified water to P Ph 9th Ed., ethanol 760 g/1, Tween 20. Dynamic viscosity test: was carried out using the Rheotest 2. The values of the shear stress and viscosity were calculated from measurements. Consistency test--TPA test was performed with Exponent Stable Micro Systems texture analyzer. Examination of pharmaceutical availability of hydrocortisone: The process of hydrocortysone release from hydrophilic base was carried out according to the method based on active substance diffusion through a semi-permeable membrane. Concentration of hydrocortysone according to Polish Pharmacopoeia 9th Ed.
Results: Rheological studies showed that the process is nonlinear. Tested gels shows thixotropic properties. The tension decreases with the increase in the percentage of excipients. Hardness tests showed that in comparison to the reference gel, pressure force increased in the presence of 1% of the excipients in the gel, and the reduction in the presence of 15% of the excipients. Gels are characterized with greater cohesiveness than the control preparation. The release process of the drug substance proceeds in accordance with first order kinetics. Increasing concentrations of used absorption promotors influenced on increase the number of hydrocortisone released from the hydrogels prepared on the basis of 3% Carbopol 934 F gel.
Conclusions: 1. Tested gels are showing thixotropic propereties and are non-Newtonian systems. 2. The hardness and cohesiveness of the gels increases with increasing concentrations of the excipients. 3. The value of the constant release rate is increases in the presence of ethanol, Tween 20, and DMA.