Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Ebru BAŞARAN, Müzeyyen DEMİREL, Yasemin YAZAN Anadolu University, Faculty of Pharmacy, Department of Pharmaceutical Technology 26470 Eskişehir- TURKEY Cyclosporine A (CsA) is a powerful immunosuppressive active agent mainly used for Particle sizes (Figure 1) and the zeta potentials (Figure 2) of the formulation remained unchanged during autoimmune diseases and graft rejections after organ transplantations [1]. Topical the storage at different conditions (25ºC±1ºC, 40ºC±1ºC, 4ºC±1ºC) for a period of 6 months. application of CsA is preferred for the ocular treatment of disorders after corneal Stability of the lipid structure analyzed by XRD (Figure 3), FT-IR (Figure 4) and 1H-NMR (Figure 5) showed transplantation and dry eye syndrome [2]. that these data support the DSC data (Figure 6) indicating the stability of the formulations for 6 months. Solid lipid nanoparticles (SLN) were introduced as alternative carrier systems for controlled release of pharmaceutical and cosmetic active compounds [3]. Particles of the system remain in the solid state at room temperature and therefore the mobility of incorporated drug is reduced which is a prerequisite for controlled drug release [4]. Possibility of controlled drug release and drug targeting, increased drug stability, high drug payload, incorporation of both lipophilic and hydrophilic drugs, avoidance of organic solvents and no problem with respect to large scale production and sterilization were the proposed advantages of SLNs [5]. Figure 1. Particle size measurements of FD4 formulation Figure 2. Zeta potential measurements of FD4 formulation during the storage time during the storage time Systemic absorption of CsA is quite low and there is interindividual variation in plasma concentrations depending on the dosage form applied and the story of the patient [6]. Therefore, in this study, cationic SLNs were prepared, aiming the ocular delivery of CsA with an attempt to decrease the interindividual variation and thus to increase its topical absorption. MATERIALS Cyclosporine-A Novartis, Switzerland Active agent (Gift) Dynasan® 116 Condea, Germany Solid lipid Stearylamine Fluka, USA Cationic agent Benzalconium chloride Fluka, Denmark Antimicrobial agent Tween® 80 Merck, Germany Surfactant Figure 5. 1H-NMR spectra of Figure 3. XRD spectra of FD4 formulation Figure 4. FT-IR spectra of FD4 formulation METHODS FD4 formulation SLN formulation (Table 1) was prepared by hot homogenization technique [4]. Homogenization was achieved with Ultraturrax (T25, IKA) at a stirring rate of 13500 rpm for 5 minutes, at 85ºC±1ºC. Table 1. Composition of the formulation Dynasan® 116 CsA Stearylamine Benzalconium chloride [a] Tween® 80 Code FD4 [b] [c] Figure 6. DSC thermograms of FD4 formulation during the storage time at 25ºC±1ºC [a], 40ºC±1ºC [b] and 4ºC±1ºC [c] (%) (%) (%) (%) (%) 6 0.1 1.5 0.01 4 In Vivo Studies CsA was determined in the aqueous and vitreous As the sterility of the ocular formulations is necessary, the formulation was sterilized by autoclaving at 121°C for 20 minutes. humour samples for 48 hours (Figure 7). Detection of CsA in the vitreous humour showed the efficient Particle size and zeta potential measurements were carried out by Malvern Nano ZS penetration of the drug to the deeper layers of the and the structure of the solid lipid was analyzed using differential scanning eyes. Similarity in the analysis results demonstrated calorimetry (DSC-60, Shimadzu), X-Ray Diffractometry (XRD) (RIKAGU D/Max-3C), that interindividual variance did not affect the Fourier Transform Infrared Spectrophotometry (FT-IR) (Perkin Elmer Spektrum 2000) absorption level of CsA. Figure 7. CsA concentrations in aqueous and vitreous humour samples and solid state NMR Spectrophotometry (1H-NMR). Stability of the formulation was monitored for 6 months at different conditions (25ºC±1ºC, 40ºC±1ºC, 4ºC±1ºC). In vivo studies were carried on the sheep. Formulation was applied topically to one According to the in vitro tests results, cationic SLN formulation remained stable during the storage of the eyes and the other eye remained untreated as a reference. At appropriate time period of 6 months. After the topical application of the formulation to the eyes, detection of CsA at the intervals, sheep were sacrificed and the aqueous and vitreous humour samples were deeper layers, and no existence of interindividual variance in the CsA concentrations showed the collected and analyzed by enzyme immune assay analyzer. efficiency of SLN formulation on the absorption of such a problematic drug. [1] [2] [3] [4] [5] [6] Y-J. Lee, S-J. Chung, C-K. Shim, J. Pharm. Biomed. Anal., 22(1), 183-188 (2000). S. Tamilvanan, K. Khoury, D. Gilhar, S. Benita, S.T.P Pharm. Sci., 11(6), 421-426 (2001). E. Cengiz, S.A. Wissing, R.H. Müller, Y. Yazan, Int. J. Cosmet. Sci., 28, 371-378 (2006). K. Manjunath, J.S. Reddy, V. Venkateswarlu, Methods Find. Exp. Clin. Pharmacol., 27(2), 127-144 (2005). R.H. Müller, M. Radtke, S.A. Wissing, Adv. Drug Deliv. Rev., 54(1), 131-155 (2002). M. Stettin, G. Halwachs-Baumann, B. Genser, F. Frühwırth, W. März, G.A. Khoschsorur, Talanta, 69, 1100–1105 (2006).