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Compared with traditional drug delivery methods, transdermal drug delivery has many advantages in avoiding the side effects in gastrointestinal tract, reducing the fluctuations in drug concentration, and improving patients' compliance. Among them, electrically controlled drug delivery is a promising solution. This work presents a wireless, battery-free and wearable device with electrically controlled drug delivery capability. The electronic component of the device is a flexible circuit board with a temperature sensor and a near-field communication module. With the help of smartphone, the device could wirelessly obtain energy and implement data transmission. The drug delivery component is a paper-based electrode modified with polypyrrole, in which non-steroidal anti-inflammatory drug sodium salicylate was encapsulated. The applied potential for electrically controlled drug delivery was more negative than -0.6 V. The drug release dose and release rates could be controlled by applying potentials with different amplitudes and durations through this device. It provided a minimalized wearable transdermal drug delivery platform for monitoring diseases such as gout. This wearable device shows promising potential in develop closed-loop drug delivery and monitoring systems for the treatment of various diseases.

In this work, we present a new iSIMPLE concept (infusion Self-powered Imbibing Microfluidic Pump by Liquid Encapsulation), which requires no external power for activation nor liquid manipulation, it is easy to use while its fabrication method is extremely simple, inexpensive and suited for mass replication. The pump consists of a working liquid, which is - after finger activation - absorbed in a porous material (e.g. filter paper). The air expelled from the porous material increases the pressure in the downstream outlet channel and propels the outlet liquid (i.e. the sample) through the channel or ejects it. Here we investigated the influence of different filter papers on the iSIMPLE flow rates, achieving a wide range from 30 down to 0.07 μL/min. We also demonstrated the versatility of the iSIMPLE in terms of the liquid volume that can be manipulated (from 0.5 μL up to 150 μL) and the working pressure reaching 64 kPa, unprecedented high for a self-powered microfluidics pump. In addition, using a 34 G microneedle mounted on the iSIMPLE, we successfully injected liquids with different viscosities (from 0.93 up to 55.88 cP) both into an agarose matrix and a skin-like biological ex vivo substrate (i.e. chicken breast tissue). This work validated the compatibility of the iSIMPLE with drug delivery in a controlled way into a skin-like matrix, envisioning a whole new scenario for intradermal injections using self-contained skin patch. In addition, due to the extreme flexibility of the design and manufacturing, the iSIMPLE concept offers enormous opportunities for completely autonomous, portable and cost effective LOC devices.

Background: A bridging study was performed to compare the safety, dose delivery, and acceptability of a prefilled plastic and user-filled paper applicator to assess whether a low-cost, user-filled, paper applicator could serve as a delivery option for tenofovir (TFV) 1% vaginal microbicide gel., Methods: The study used a randomized crossover design with 25 healthy women randomized to begin with the prefilled or user-filled applicator. Within each study arm, participants delivered two 4.0-mL doses of TFV 1% gel vaginally for 7 days, with one dose delivered at the clinic each morning and a second dose delivered at home each evening. To assess the primary objective, applicator safety, colposcopy examinations were performed at 2 time points in each study arm., Results: There were no colposcopic findings or adverse events attributable to either applicator. One case of vulvovaginal candidiasis was considered possibly related to gel use. On average, the user-filled applicator delivered 96% of the target dose, with 85% of doses falling within ± 10% of the average dose volume. Participants found both applicators comparable for ease of use, insertion, and dispensing gel, with 60% of participants preferring the user-filled applicator., Conclusions: This study suggests that both applicators are safe, and most women delivered TFV with the user-filled applicator as directed. Participants found both applicators acceptable, with a slight majority preferring the user-filled applicator. Incorporating a low-cost, user-filled, paper applicator to deliver TFV could help reduce costs and improve access to TFV 1% gel, especially in resource-limited settings heavily impacted by HIV.

We combined conventional inkjet printing technology with flexographic printing to fabricate drug delivery systems with accurate doses and tailored drug release. Riboflavin sodium phosphate (RSP) and propranolol hydrochloride (PH) were used as water-soluble model drugs. Three different paper substrates: A (uncoated woodfree paper), B (triple-coated inkjet paper) and C (double-coated sheet fed offset paper) were used as porous model carriers for drug delivery. Active pharmaceutical ingredient (API) containing solutions were printed onto 1 cm × 1 cm substrate areas using an inkjet printer. The printed APIs were coated with water insoluble polymeric films of different thickness using flexographic printing. All substrates were characterized with respect to wettability, surface roughness, air permeability, and cell toxicity. In addition, content uniformity and release profiles of the produced solid dosage forms before and after coating were studied. The substrates were nontoxic for the human cell line assayed. Substrate B was smoothest and least porous. The properties of substrates B and C were similar, whereas those of substrate A differed significantly from those of B, C. The release kinetics of both printed APIs was slowest from substrate B before and after coating with the water insoluble polymer film, following by substrate C, whereas substrate A showed the fastest release. The release rate decreased with increasing polymer coating film thickness. The printed solid dosage forms showed excellent content uniformity. So, combining the two printing technologies allowed fabricating controlled-release oral dosage forms that are challenging to produce using a single technique. The approach opens up new perspectives in the manufacture of flexible doses and tailored drug-delivery systems., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Purpose: To compare the quantity of fluorescein delivered to the eye via fluorescein-impregnated paper strips of various sizes and surface areas and via various microliter volumes of fluorescein sodium using an in vitro assay., Methods: A commercially available fluorescein-impregnated strip (75 mm2) and three modified strips of reduced fluorescein-impregnated surface areas (10, 7.5, and 5.0 mm2) were used. The amount of fluorescein delivered to the eye for each of the four strips was approximated by applying each strip to a Whatman No. 1 filter paper under conditions simulating application of the strip to the eye, extracting the fluorescein from the filter paper in an aqueous solution, and performing spectrophotometric analysis at 484 nm. Similarly, this filter paper analytical system was calibrated using 1, 2, and 3 microl volumes of 2% w/v fluorescein delivered to the filter paper., Results: Using calibration curves, linearity was observed between absorbance and concentration of fluorescein sodium with an R2 value > or = 0.99. Using these calibration curves, the amount of fluorescein delivered to the eye for the four strips and the three fluorescein solution samples was determined. Fluorescein-impregnated strips with surface areas of 75, 10, and 5 mm2 delivered approximately the same quantity of fluorescein to the ocular surface as 3 microl, 1 microl, and 0.5 microl of fluorescein 2% solution, respectively., Conclusions: The surface area of the fluorescein-impregnated portion of the strip can be designed to control the amount of fluorescein delivered to the eye.

Purpose: The technique of administration and the resulting volume and concentration of the dye delivered to the eye via dye-impregnated paper strips are not standardized or known. The purpose of this study was to use a standard technique for preparation of rose bengal dye from commercially available paper strips to determine the variability in concentration based upon soak time, and to determine the volume delivered by such a technique to a model eye., Methods: Rose bengal filter paper strips were wetted for either 15, 30, or 45 s, and the resulting concentration of dye eluted was determined by spectrophotometry. With the same preparation technique and a 15-s soak time, the strip was applied to wetted filter paper, as a model for the moist surface of the eye. The volume of solution delivered was calculated by weight., Results: Concentrations of rose bengal for the various soak times were: 15 s: 7.64 (+/- 1.11) by 10(-6) g/ml; 30 s: 9.70 (+/- 1.79) by 10(-6) g/ml; and 45 s: 10.27 (+/- 0.66) by 10(-6) g/ml. The volume delivered to the eye model with this technique was 17.43 microliters (+/- 3.09)., Conclusions: The concentration of rose bengal dye delivered to the ocular surface by means of a wetted strip is relatively low and soak time/technique-dependent. This suggests a possibility that results in clinical studies with rose bengal strip application may be different than if controlled volume applications of commercially available 1% liquid rose bengal dye are used.