The aim of this study was to develop heparin sodium loaded microneedle patches using different compositions of polyvinyl alcohol polymer and sorbitol. A vacuum micromolding technique was used to fabricate microneedle patches while heparin sodium was loaded into needle tips. Physical features of patches were evaluated by measuring thickness, width, folding endurance and swelling percentage. Patches were also characterized by optical microscopy and scanning electron microscopy to determine the microneedle length and surface morphologies. A preliminary assessment of the microneedle performance was studied by examining the in-vitro insertion to the parafilm and recording the in-vitro drug release profile. In-vivo activity of patches was confirmed by measuring activated partial thromboplastin time and histological examination of the micropierced skin tissues. Prepared patches were clear, smooth; uniform in appearance; with sharp pointed microprojections and remained intact after 1000 folding. The microneedles were stiffer in nature, as they reproduce microcavities in the parafilm membrane following hand pushing without any structural loss. Insertion study results showed successful insertion of microneedles into the parafilm. Disrupted stratum corneum evident from histological examination confirmed successful insertion of the microneedle without affecting the vasculature. In-vitro release study confirmed ∼92% release of the loaded drug within 120 minutes. A significant prolongation of activated partial thromboplastin time (4 folds as compared to negative control) was recorded following the application of heparin sodium loaded microneedle patch onto rabbit skin. In conclusion microneedles are a valuable drug delivery system, benefiting the patients with minimal skin invasion and also allowing self-administration of heparin sodium in a sustained release manner for the management of chronic ailments.

这项研究的目的是使用聚乙烯醇聚合物和山梨糖醇的不同组成来开发肝素钠微针贴剂。在将肝素钠装入针尖的同时，使用真空微成型技术制造微针贴剂。通过测量厚度，宽度，耐折性和溶胀率来评估贴剂的物理特征。还通过光学显微镜和扫描电子显微镜表征贴剂，以确定微针长度和表面形态。通过检查体外插入封口膜并记录体外药物释放曲线，对微针性能进行了初步评估。体内通过测量活化的部分凝血活酶时间和微穿刺皮肤组织的组织学检查证实了斑块的活性。准备好的补丁清晰，平滑；外观均匀；具有尖锐的微突起，经过1000次折叠后仍保持完整。微针本质上更硬，因为它们在手推后会在旁膜膜中繁殖微腔，而没有任何结构损失。插入研究结果表明，微针已成功插入封口膜。从组织学检查可见，角质层破裂证实了微针的成功插入，而没有影响脉管系统。体外释放研究证实在120分钟内〜92％的载药释放。在将肝素钠微针贴剂应用到兔皮肤上后，记录了活化的部分凝血活酶时间的显着延长（是阴性对照的4倍）。总而言之，微针是一种有价值的药物输送系统，它可以使皮肤侵袭最小的患者受益，也可以以持续释放的方式自我施用肝素钠来治疗慢性疾病。