Correlation between health literacy and health-related quality of life in patients with diabetic peripheral neuropathy: The mediating role of self-management.

AIM: The aims of the study were to analyse the current situation of health literacy (HL), self-management and health-related quality of life (HRQOL) in patients with diabetic peripheral neuropathy (DPN), to explore the correlation between the three and to verify the mediating role of self-management in HL and HRQOL. DESIGN: A cross-sectional survey. METHODS: The convenience sampling method was used to select 401 DPN patients attending the First Hospital of Jinzhou Medical University in Liaoning Province, China, from December 2020 to December 2021 as the study population. The research instrument included socio-demographic characteristics questionnaire, Health Literacy Management Scale (HeLMS), Summary of Diabetes Self-Care Activities (SDSCA) and Short-Form 12-item Health Survey (SF-12). SPSS 25.0 was applied to the data for descriptive analysis, Pearson correlation analysis and stratified multiple regression analysis. Mediating effects were tested using SPSS PROCESS macro 4.0 software. RESULTS: HL and self-management of DPN patients correlated positively with HRQOL. The mediation role of self-management was significant in the relationship between HL and physical and mental HRQOL (physical component summary: ß = 0.26, P < 0.01; mental component summary: ß = 0.18, P < 0.01), with mediating effects accounting for 35.62% and 34.62% of the total effect. CONCLUSIONS: There was a positive correlation between HL, self-management and HRQOL in patients with DPN. Self-management plays a partially mediating role in the relationship between HL and HRQOL in DPN patients. It means that HRQOL in this population can be improved by increasing HL and thus self-management in DPN patients. PATIENT OR PUBLIC CONTRIBUTION: None.

Transdermal drug delivery by in-skin electroporation using a microneedle array.

The aim of the present work was to develop a minimally invasive system for the delivery of macromolecular drugs to the deep skin tissues, so-called in-skin electroporation (IN-SKIN EP), using a microneedle (MN) electrode array. Fluorescein isothiocyanate (FITC)-dextran (FD-4: average molecular weight, 4.3 kDa) was used as the model macromolecular drug. MNs were arranged to puncture the skin barrier, the stratum corneum, and electrodes were used for EP so that a high electric field could be applied to skin tissues to promote viable skin delivery. In vitro skin permeation experiments showed that IN-SKIN EP had a much higher skin penetration-enhancing effect for FD-4 than MN alone or ON-SKIN EP (conventional EP treatment), and that higher permeation was achieved by applying a higher voltage and longer pulse width of EP. In addition, no marked skin irritation was observed by IN-SKIN EP, which was determined by the LDH leaching test. These results suggest that IN-SKIN EP can be more effectively utilized as a potential skin delivery system of macromolecular drugs than MN alone and conventional ON-SKIN EP.

Optimized preparation of in situ forming microparticles for the parenteral delivery of vinpocetine.

A spherical symmetric design-response surface methodology was applied to optimize the preparation of vinpocetine-loaded poly(D,L-lactide-co-glycolide) PLGA in situ forming microparticles (ISM system). The influence of the ratio of PLGA to vinpocetine (w/w), the concentration of Tween 80 (w/v) and the volume of propylene glycol on the burst release, medium particle diameter and size distribution was evaluated. Scan electron microscopy of the optimized in situ microparticles exhibited spherical shape, and vinpocetine-loading mainly inside the microparticles. The data showed that the release of vinpocetine from in situ microparticles in vitro and in vivo lasted about 40 d. In vivo pharmacokinetic characteristics of the optimized in situ microparticles was assessed after they were intramuscularly injected into rats. HPLC method was used to determine the plasma concentration of vinpocetine. The absolute bioavailability of vinpocetine in the microparticles was 27.6% in rats, which suggested that PLGA in situ microparticles were a valuable system for the delivery of vinpocetine.

Novel osmotic pump tablet using core of drug-resin complexes for time-controlled delivery system.

A novel elementary osmotic pump tablet was developed. The system uses the core of drug-resin complexes (DRCs) loaded with propranolol hydrochloride (PNH) for time-controlled delivery. In traditional osmotic pump tablets (OPTs), the lag time was always minimized. However, in the DRCs osmotic pump tablet (DRCOPT), the lag time was increased to achieve the time-controlled delivery. The quantity of osmotic agent in the core and channeling agent in the coating solution as well as weight gain were confirmed to be essential for the release behavior. A spherical symmetric design was applied to the optimization of the DRCOPT. The optimal formulation mainly consisted of DRC 100 mg, polyethyleneoxide (N80) 182 mg, and NaCl 30 mg. The ratio of cellulose acetate (CA)/polyethylene glycol 4000 was 15:3 (w/w) in coating solution, and the weight gain was 8%. The release behavior of the optimal DRCOPT was evaluated in media with different pH, rotation speeds, and ionic strength. It was found to generate a 2-h lag time, to deliver PNH at a rate of zero order from 2 h to 14 h in the medium of NaCl 0.15 mol/l, and the cumulative release at 24 h was 94%. Drug relee was independent of pH and rotation speed, but was proportional to ionic strength. In summary, the lag time could be used in therapeutic regimens with the characteristics of chronotherapy because of the lag time and provides a new concept for the development of osmotic pumps.