Pharmaceutical bioavailability of combined ointments with izohydrafural and methyluracil

Abstract

Introduction: A difficult problem in the human pathology is the purulent infections due to the necessity of taking several drugs for a complex action such as: antimicrobial, regenerating, anti-inflammatory and analgesic. It is actual the elaboration of a new formulation for external use - combined ointment with izohydrafural and methyluracil, which combines the antibacterial action of izohydrafural and the regenerating and antiinflammatory actions of methyluracil. Materials and methods: In research it was used the active substances: izohydrafural, methyluracil and excipients: polyethyleneglycol 400, vaseline, stearyl alcohol, cetyl alcohol, propyleneglycol, glycerin, tween 80, sodium laurilsulphate. Also, in research it was used the device Erweka USP for the dialysis method, UV-VIS spectrophotometer Agilent-8453, Milipore membrane 0,22 mm and dimethylformamide as dissolution medium. Results: First of all it was elaborated the optimal formulation and the manufacturing technology of combined ointments. It was used different excipients, obtaining four models of combined ointments with concentrations of 0,1% for izohydrafural and 5% for methyluracil. Pharmaceutical availability of active principles from ointments was determined by the method of dialysis membrane. It was respected the conditions of method: 50 ml dimethylformamide - as dissolution medium, the temperature - 37±1°C. From the obtained dialysate, it was dosed the active substances by UV-VIS spectrophotometric method: izohydrafural at wavelength 373 nm and methyluracil at 267 nm. From the results, it was established that the maximum of disposal speed of active substances occurs in composition containing polyethylenegly­col 400, stearin alcohol, glycerin, sodium lauryl sulphate, purified water. Also, it was assayed the dissolution rate constant (Kd) and half-life time (T50%) forall four compositions. It was established that the highest value of the dissolution rate constant has the same ointment containing polyethyleneglycol 400, stearin alcohol, glycerin, sodium lauryl sulphate and purified water. For izohydrafural - Kd = 0,018 min 1 and for methyluracil - Kd = 0,064 min '. At the same composition of ointment was determined the smallest value of half-life time of 38,5 minutes for izohydrafural and half-life time of 42,2 minutes, respectively for methyluracil. Conclusions: It was concluded that the best pharmaceutical bioavailability of active principles from the four compositions of ointments resulted at ointment containing polyethyleneglycol 400, stearin alcohol, glycerin, sodium lauryl sulphate and purified water.