Publication: İlaç etken maddelerinin farklı pH koşullarında yüzey aktif madde miselleri ile etkileşimleri
Abstract
Amaç: Bu çalışmanın amacı suda az çözünen ilaç etken maddelerinden Sülfametoksazol (SMZ) ve Trimethoprim (TMP)’in anyonik yüzey aktif madde Sodyumdodesil sülfat (SDS) miselleri ile etkileşimlerini farklı pH koşullarında incelemektir.Gereç ve Yöntem: SDS’nin geniş derişim aralığında SMZ ve TMP ile etkileşim mekanizması spektrofotometre ve yüzey gerilim ölçümleri kullanılarak 298 K’ de çalışıldı. Benesi-Hildebrand eşitliği kullanılarak TMP ve SMZ’nin SDS misellerine bağlanma sabitleri hesaplandı. SDS’nin yüzey özellikleri üzerine TMP ve SMZ etkisi Gibbs Adsorpsiyon İzotermi kullanılarak ortam pH’ına bağlı olarak değerlendirildi.Bulgular: SMZ ve TMP'nin SDS misellerine bağlanma derecesi, ortamın pH koşullarına bağlı olarak farklı bir eğilim gösterdi. Ortam pH’ının TMP ve SMZ'nin hesaplanan bağlanma sabitleri üzerindeki etkisi ve SMZ ve TMP varlığında SDS'nin yüzey özellikleri üzerine etkisi değerlendirildi. TMP ve SMZ'nin SDS misellerine bağlanma eğiliminin, etken maddeler ve SDS miselleri arasındaki elektrostatik ve hidrofobik etkileşimlerin bir sonucu olduğu bulundu.Sonuçlar: Spektrofotometrik olarak belirlenen bağlanma sabitleri ve yüzey gerilimi ölçümleri kullanılarak tahmini yüzey parametreleri etken maddelerin bağlanma mekanizmasını açıklamak için kullanıldı. SDS’nin yüzey gerilim ölçümleriyle izlenen yüzey özellikleri ile spektrofotometrik ölçümlerle hesaplanan bağlanma sabiti değerleri birbirleriyle uyum gösterdi. Bu model çalışma ile izlenecek olan ortam pH’ının etkilerinin sonuçlarının, özellikle taşıyıcı sistemlerin (miseller veya modifiye edilmiş miseller) geliştirilmesinde ve çözündürme çalışmalarında kullanılmak üzere katkı sağlayacağı düşünülmektedir.
Objective: The aim of this study was to examine interactions of poorly soluble drugs i.e. sulfamethoxazole (SMZ) and trimethoprim (TMP) with anionic surfactant sodiumdodecyl sulfate (SDS) in different pH conditions at 298 K.Methods: Spectrophotometry and surface tension measurements were used to study interaction mechanism of SMZ and TMP in wide range concentration of anionic surfactant SDS micelles at 298 K. The binding constants of TMP and SMZ to SDS micelles were calculated by means of Benesi-Hildebrand Equation and the influence of TMP and SMZ on surface properties of SDS was evaluated using Gibbs Adsorption Isotherm based on pH conditions. Results: The binding ability of SMZ and TMP in the presence of SDS micelles showed a different trend depending on pH conditions of the medium. The effect of medium pH on calculated binding constants of TMP and SMZ has been evaluated as well as surface properties of SDS in the presence of SMZ and TMP. It was found that the binding tendency of TMP and SMZ for SDS micelles is a consequence of the electrostatic and hydrophobic interactions between drugs and SDS micelles. Conclusion: The binding constants determined spectrophotometrically and the estimated surface properties of SDS employing the surface tension measurements are used to explain binding mechanism of drugs. Changes in surface properties of SDS determined by surface tension measurements in the presence of drugs are in good agreement with the binding constants determined spectrophotometrically. The results of this model study will contribute to the development of the carrier systems (micelles or modified micelles) and to be used in the dissolution studies in terms of the effects of the pH on the interactions between drugs and surfactants.
Objective: The aim of this study was to examine interactions of poorly soluble drugs i.e. sulfamethoxazole (SMZ) and trimethoprim (TMP) with anionic surfactant sodiumdodecyl sulfate (SDS) in different pH conditions at 298 K.Methods: Spectrophotometry and surface tension measurements were used to study interaction mechanism of SMZ and TMP in wide range concentration of anionic surfactant SDS micelles at 298 K. The binding constants of TMP and SMZ to SDS micelles were calculated by means of Benesi-Hildebrand Equation and the influence of TMP and SMZ on surface properties of SDS was evaluated using Gibbs Adsorption Isotherm based on pH conditions. Results: The binding ability of SMZ and TMP in the presence of SDS micelles showed a different trend depending on pH conditions of the medium. The effect of medium pH on calculated binding constants of TMP and SMZ has been evaluated as well as surface properties of SDS in the presence of SMZ and TMP. It was found that the binding tendency of TMP and SMZ for SDS micelles is a consequence of the electrostatic and hydrophobic interactions between drugs and SDS micelles. Conclusion: The binding constants determined spectrophotometrically and the estimated surface properties of SDS employing the surface tension measurements are used to explain binding mechanism of drugs. Changes in surface properties of SDS determined by surface tension measurements in the presence of drugs are in good agreement with the binding constants determined spectrophotometrically. The results of this model study will contribute to the development of the carrier systems (micelles or modified micelles) and to be used in the dissolution studies in terms of the effects of the pH on the interactions between drugs and surfactants.