Ghasemi Shayan Ramin, Jalaei Dorsa, Dobakhti Faramarz
Radiology Department, Paramedical Faculty, Tabriz University of Medical Sciences, Tabriz, Iran.
School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran.
BMC Pharmacol Toxicol. 2025 Apr 9;26(1):77. doi: 10.1186/s40360-025-00917-z.
Ophthalmic drugs typically last only around 15 minutes due to rapid elimination from tear flow, with only about 2% absorption, while the rest may enter the nasal mucosa, potentially causing systemic side effects. Diatoms, with properties like unique structure, abundance, low cost, heat resistance, non-toxicity, and easy access, present a promising solution for sustained drug delivery. This study aimed to prepare and evaluate an ocular suspension of diclofenac sodium loaded onto modified diatoms.
Diatoms were modified with aluminum sulfate solution, followed by loading of diclofenac sodium. Characteristics of diatoms before and after modification-particle size, surface charge, and drug loading-were analyzed using electron microscopy, FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-ray Diffraction), and elemental mapping. BET (Brunauer-Emmett-Teller (Surface Area Analysis) testing provided adsorption data, while DSC (Differential Scanning Calorimetry) assessed thermal properties. An in vitro release study using a dialysis bag in artificial tear fluid examined drug release over 8 hours. Drug content was determined by spectrophotometry, and cytotoxicity on MDA-MB-231 and HEP-G2 cell lines was evaluated at different diatom concentrations.
SEM (Scanning Electron Microscopy) imaging showed no topographic changes post-modification. BET and XRD analyses confirmed drug loading and structural stability, while FTIR indicated involvement of carboxylate groups. TGA and DSC showed stable thermal properties. Elemental mapping confirmed increased surface elements and high drug loading. Modified diatoms showed sustained drug release and no significant cytotoxicity differences.
Modified diatoms demonstrated higher drug loading and sustained release, indicating their potential for safe and effective ocular drug delivery. Further studies are recommended to confirm these findings.
由于泪液流动导致药物快速清除，眼科药物通常仅持续约15分钟，吸收率仅约2%，其余部分可能进入鼻粘膜，从而可能引起全身副作用。硅藻具有独特的结构、丰富性、低成本、耐热性、无毒性且易于获取等特性，为药物持续递送提供了一种有前景的解决方案。本研究旨在制备并评估负载于改性硅藻上的双氯芬酸钠眼用混悬液。
用硫酸铝溶液对硅藻进行改性，随后负载双氯芬酸钠。使用电子显微镜、傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）和元素映射分析改性前后硅藻的特性——粒径、表面电荷和载药量。BET（布鲁诺尔-埃米特-泰勒（表面积分析）测试提供吸附数据，而差示扫描量热法（DSC）评估热性质。使用透析袋在人工泪液中进行体外释放研究，检测8小时内的药物释放情况。通过分光光度法测定药物含量，并在不同硅藻浓度下评估对MDA-MB-231和HEP-G2细胞系的细胞毒性。
扫描电子显微镜（SEM）成像显示改性后无形貌变化。BET和XRD分析证实了药物负载和结构稳定性，而FTIR表明羧酸盐基团参与其中。热重分析（TGA）和DSC显示热性质稳定。元素映射证实表面元素增加且载药量高。改性硅藻显示出药物持续释放且细胞毒性无显著差异。
改性硅藻显示出更高的载药量和持续释放，表明其在安全有效的眼部药物递送方面的潜力。建议进一步研究以证实这些发现。
