Niaz Taskeen, Shabbir Saima, Manzoor Shahid, Rehman Asma, Rahman Abdur, Nasir Habib, Imran Muhammad
Department of Biosciences, COMSATS Institute of Information Technology, Park road, Islamabad, Pakistan.
Department of Materials Science and Engineering, Institute of Space Technology, Islamabad 44000, Pakistan.
Carbohydr Polym. 2016 May 20;142:268-74. doi: 10.1016/j.carbpol.2016.01.047. Epub 2016 Jan 25.
Prime risk factor behind cardiovascular associated mortality and morbidity is hypertension. The main challenge with antihypertensive (AHT) drug therapy is their extreme hydrophobic nature and very low oral bio-availability; which result into higher dosage/frequency and associated side effects of drugs. The main objective of this study was to fabricate AHT nano-ceuticals in hydrophilic carriers of natural origin to improve drugs' solubility, protection and sustained release. AHT nano-carrier systems (NCS) encapsulating captopril, amlodipine and valsartan were fabricated using chitosan (CS) polymer by ionic gelation assisted ultra-sonication method. Drug encapsulation efficiencies of 92±1.6%, 91±0.9% and 87±0.5% were observed for captopril, valsartan and amlodipine respectively. Scanning electron microscopy (SEM) based analysis had revealed that captopril loaded polymeric NCS were regular, smooth and without any agglomeration. FTIR analyses of drug loaded and empty NCS demonstrated that drugs were molecularly dispersed inside the nanoparticles via week hydrogen bonding. Captopril and valsartan have demonstrated grafting reaction with N-H group of chitosan. Zeta sizer results had confirmed that average size of chitosan nanoparticles was below 100 nm. Encapsulation of captopril had reduced the surface charge value from +52.6±4.8 to +46.5±5.2 mV. Controlled release evaluation of highly encapsulated drug captopril had revealed a slow release in vitro from NCS in physiological buffer. Thus, here reported innovative AHT nano-ceuticals of polymeric origin can improve the oral administration of currently available hydrophobic drugs while providing the extended-release function.
心血管相关死亡率和发病率背后的主要风险因素是高血压。抗高血压（AHT）药物治疗的主要挑战在于其极强的疏水性和极低的口服生物利用度；这导致药物剂量/服用频率增加以及相关副作用。本研究的主要目的是在天然亲水性载体中制备AHT纳米药物，以提高药物的溶解度、保护作用和缓释性能。采用壳聚糖（CS）聚合物通过离子凝胶辅助超声法制备了包封卡托普利、氨氯地平和缬沙坦的AHT纳米载体系统（NCS）。卡托普利、缬沙坦和氨氯地平的药物包封率分别为92±1.6%、91±0.9%和87±0.5%。基于扫描电子显微镜（SEM）的分析表明，负载卡托普利的聚合物NCS形状规则、表面光滑且无任何团聚现象。对负载药物和空白NCS的傅里叶变换红外光谱（FTIR）分析表明，药物通过弱氢键分子分散在纳米颗粒内部。卡托普利和缬沙坦已证明与壳聚糖的N-H基团发生了接枝反应。Zeta粒度仪结果证实壳聚糖纳米颗粒的平均尺寸低于100 nm。卡托普利的包封使表面电荷值从+52.6±4.8 mV降低至+46.5±5.2 mV。对高度包封的药物卡托普利进行的控释评估表明，其在生理缓冲液中从NCS体外缓慢释放。因此，本文报道的创新型聚合物来源的AHT纳米药物可以改善目前可用疏水性药物的口服给药，同时提供缓释功能。
