Transdermal delivery of fluorescein isothiocyanate-dextrans using the combination of microneedles and low-frequency sonophoresis

This study aimed to evaluate the patient-friendly methods that are used in the delivery of hydrophilic macromolecules into deep skin layers,in particular,the combination of microneedles patch(MNs patch)and low-frequency sonophoresis(SN).The hydrophilic macromolecule drug fluorescein isothiocyanate(FITC)-dextrans(FD-4:MW 4.4 kDa)was used as the model drug in our experimental design.In this study,excised porcine skin was used to investigate and optimize the key parameters that determine effective MNs-and SNfacilitated FD-4 delivery.In vitro skin permeation experiments revealed that the combination of MNs patch with SN had a superior enhancing effect of skin permeation for FD-4 compared to MNs alone,SN alone or untreated skin,respectively.The optimal parameters for the combination of MNs and SN included the following:10 N insertion force of MNs,4 W/cm^(2)SN intensity,6 mm radiation diameter of the SN probe,2 min application time,and the continuous mode duty cycle of SN.In addition,vertical sections of skin,clearly observed under a confocal microscope,confirmed that the combination of MNs and SN enhanced permeation of FD-4 into the deep skin layers.These studies suggest that the combination of MNs and SN techniques could have great potential in the delivery of hydrophilic macromolecules into deep skin.

Topical Delivery of Modified Da-Cheng-Qi Decoction(加味大承气汤) Using Low-Frequency Ultrasound Sonophoresis for Refractory Metastatic Malignant Bowel Obstruction:An Open-Label Single-Arm Clinical Trial

Objective:To evaluate the efficacy and safety of topical delivery of modified Da-Cheng-Qi Decoction(加味大承气汤,MDCQD)by low-frequency ultrasound sonophoresis(LFUS)in patients with refractory metastatic malignant bowel obstruction(MBO)using an objective performance criteria(OPC)design.Methods:Fifty patients with refractory metastatic MBO were enrolled in this open-label single-arm clinical trial.Alongside fasting,gastrointestinal decompression,glycerol enema,intravenous nutrition and antisecretory therapy,a 50 g dose of MDCQD(prepared as a hydrogel)was applied through topical delivery at the site of abodminal pain or Tianshu(S 25)using LFUS for 30 min,twice daily for 5 consecutive days.The overall outcomes were the remission of intestinal obstruction,improvement on abdominal pain,abdominal distention,nausea and vomiting scores.Indicators of safety evaluation included liver and renal function as well as blood coagulation indicators.Results:Among 50 patients,5 patients(10%)showed complete remission of intestinal obstruction and 21 patients(42%)showed improvement of intestinal obstruction.The overall remission rate of bowel obstruction was 52%.The results of the symptom score,based on the severity and frequency of the episode,were as follows:26 patients(52%)showed improvment on symptom scores,20 patients(40%)did not respond to treatment,and 4 patients(8%)discontinued treatment due to intolerance.No serious adverse effects or abnormal changes on liver and renal functions or blood coagulation were observed.Conclusion:Topical delivery of MDCQD at 100 g/day using LFUS can improve the treatment response in patients with refractory metastatic MBO.