As a relatively novel technique for drug delivery, the needle-free injection technique is characterized by transporting the drug liquid to the designated subcutaneous position through a high-speed micro-jet. Although this technique has been applied in many fields, the research on its drug dispersion mechanism and injection performance is insufficient. The presented study aims to identify critical parameters during the injection process and describe their influence on the injection effect. The injection completion rate and performance of a needle-free injector under various operating conditions were compared based on mouse experiments. The results show that the nozzle diameter imposes a more significant influence on jet characteristics than other injection parameters. Moreover, the injection completion rate increases with the nozzle diameter. The nozzle diameters of 0.14 mm and 0.25 mm correspond to injection completion rates of 89.7% and 95.8%, respectively. Furthermore, by analyzing the rate of blood glucose change in the tested mice, it is found that insulin administration through the needle-free injection can achieve a drug effect duration longer than 120 min, which is better than that obtained using conventional needle-syringe technique. In summary, the obtained conclusions can provide an important reference for the optimal design and extending application of the air-powered needle-free injector.
Animals ; Mice ; Insulin/administration & dosage* ; Needles ; Injections, Subcutaneous/methods* ; Injections, Jet/instrumentation* ; Drug Delivery Systems/instrumentation* ; Blood Glucose/analysis* ; Equipment Design

Compared with conventional transdermal drug delivery systems, dissolving microneedles significantly enhance drug bioavailability by penetrating the stratum corneum barrier and achieving intradermal drug delivery. In order to improve the transdermal bioavailability of dexmedetomidine hydrochloride, in this study, a novel microneedle delivery system was developed for dexmedetomidine hydrochloride based on 3D printing combined with micro-molding. By systematically optimizing the microneedle geometrical parameters, array arrangement, and preparation process parameters, we determined the optimal ratio of drug-carrying matrix as 15% PVP (polyvinyl pyrrolidone) K90. The microneedles exhibited significant drug loading gradients, with mean content of (209.99±27.56) μg/patch, (405.31±30.31) μg/patch, and (621.61±34.43) μg/patch. They showed a regular pyramidal structure under SEM and handheld electron microscopy, and their mechanical strength allowed effective penetration into the stratum corneum. The surface contact angles were all < 90°, indicating excellent hydrophilicity. The microneedles dissolved completely within 10 min after skin insertion, achieving a cumulative release rate of 90% (Higuchi model, r=0.996) during 2 hours of in vitro transdermal permeation. The cytotoxicity test and hemolysis test verified good biocompatibility. Pharmacodynamic evaluation showed that the microneedle group demonstrated pain-relieving effect within 15 min, with the pain threshold at the time point of 60 min being 3 times that in the transdermal cream group. The microneedle system developed in this study not only offers an efficient drug delivery option for patients but also establishes an innovative platform for rapid percutaneous delivery of hydrophilic drugs, demonstrating significant potential in perioperative pain management.
Dexmedetomidine/pharmacokinetics* ; Printing, Three-Dimensional ; Needles ; Drug Delivery Systems/methods* ; Administration, Cutaneous ; Animals ; Microinjections/instrumentation* ; Skin Absorption ; Skin/metabolism*

Conventional administration methods have problems including low bioavailability, complex operation process, and discomfort of patients with fear of needles. Transdermal delivery can avoid these problems, whereas most drugs are difficult to directly penetrate the skin cuticle and reach the diseased site. Microneedling is an emerging method of local drug delivery, enabling the drug penetration through the stratum corneum of the skin in a minimally invasive manner and delivering the drug directly to the diseased site, thereby improving the treatment effect. Stimuli-responsive microneedles have attracted much attention because of the spatiotemporal controllability, high drug delivery efficiency, and mild potential side effects. This review introduced the commonly used materials and various types of stimuli-responsive microneedles and the drug release mechanisms. In addition, this paper expounded the biomedical applications of stimuli-responsive microneedles as drug delivery systems in response to different stimuli and discusses the challenges and potential solutions for stimuli-responsive microneedles.
Needles ; Drug Delivery Systems/instrumentation* ; Microinjections/instrumentation* ; Humans ; Administration, Cutaneous

Drug-device combination product, which comprises at least a drug and a medical device, has been proved to effectively reduce the risk of complications accompanied with conventional medical devices implantation, and has a great clinical success especially in implantable therapeutics. Herein, we firstly elaborated the definitions and requirements of drug-device combination product in different countries, then summarized the market application and research development of typical drug-device combination products. Technical problems and the trend of future development had also been analyzed.
Drug Delivery Systems/instrumentation* ; Equipment Design ; Prostheses and Implants

To evaluate the efficacy and safety of drug-eluding beads transarterial chemoembolization (DEB-TACE) in treatment of unrecectable hepatocellular carcinoma (HCC).The clinical data of 42 consecutive HCC patients undergoing TACE were retrospectively analyzed, including 20 cases received conventional TACE (cTACE group) and 22 cases received TACE with epirubicine-loaded microspheres (CalliSpheres) (DEB-TACE group). MRI scans were performed 1 week before and 1, 3 and 6 months after initial therapy. The response to treatment, disease recurrence, complications and adverse effects were documented and compared between two groups.There were no significant differences in 1-month, 3-month and 6-month objective response rate (CR+PR) and disease control rate (CR+PR+SD), disease recurrence, complications and adverse effects of interventional therapy between cTACE group and DEB-TACE group. Additionally, there were no significant differences about locoregional biliary injuries, intrahepatic biloma, and newly detected intra- or extrahepatic HCC on MRI between cTACE group and DEB-TACE group.There were no statistically significant differences between cTACE group and DEB-TACE group with regard to the short-term response, disease recurrence, complications and side effects. Hepatic-locoregional complications may be more frequent in DEB-TACE group than those in cTACE group.
Carcinoma, Hepatocellular ; diagnostic imaging ; therapy ; Chemoembolization, Therapeutic ; adverse effects ; instrumentation ; methods ; Comparative Effectiveness Research ; Drug Delivery Systems ; instrumentation ; methods ; Epirubicin ; administration & dosage ; therapeutic use ; Humans ; Liver Neoplasms ; Magnetic Resonance Imaging ; Microspheres ; Neoplasm Recurrence, Local ; Retrospective Studies ; Treatment Outcome

New enrofloxacin microspheres were formulated, and their physical properties, lung-targeting ability, and tissue distribution in rats were examined. The microspheres had a regular and round shape. The mean diameter was 10.06 microm, and the diameter of 89.93% of all microspheres ranged from 7.0 microm to 30.0 microm. Tissue distribution of the microspheres was evaluated along with a conventional enrofloxacin preparation after a single intravenous injection (7.5 mg of enrofloxacin/kg bw). The results showed that the elimination half-life (t(1/2beta)) of enrofloxacin from lung was prolonged from 7.94 h for the conventional enrofloxacin to 13.28 h for the microspheres. Area under the lung concentration versus time curve from 0 h to infinity (AUC(0-infinity)) was increased from 11.66 h.microg/g to 508.00 h.microg/g. The peak concentration (Cmax) in lung was increased from 5.95 microg/g to 93.36 microg/g. Three lung-targeting parameters were further assessed and showed that the microspheres had remarkable lung-targeting capabilities.
Animals ; Anti-Bacterial Agents/*adverse effects ; Drug Delivery Systems/instrumentation/*methods ; Female ; Fluoroquinolones/*adverse effects ; Half-Life ; Humans ; Injections, Intravenous ; Lung/*drug effects ; Male ; *Microspheres ; Rats ; Rats, Sprague-Dawley ; Tissue Distribution

The present study was designed to develop and evaluate glycyrrhetinic acid-graft-hyaluronic acid (HGA) conjugate for intravenous paclitaxel (PTX) delivery. Lyophilized PTX-loaded self-assembled HGA nanoparticles (PTX/HGAs) were prepared and characterized by dynamic light scattering measurements. Hemolysis test, intravenous irritation assessment, and in vitro and in vivo pharmacodynamic studies were carried out. B16F10 and HepG2 cells were used in the cell apoptosis analysis. The mouse MDA-MB-231 xenograft model was used for the evaluation of in vivo anticancer activity of the drugs, by the analysis of tumor growth and side effects on other tissues. PTX/HGAs showed high stability and good biocompability. Compared with PTX plus GA plus HA solution, PTX/HGAs displayed obvious superiority in inducing the apoptosis of the cancer cells. Following systemic administration, PTX/HGAs efficiently suppressed tumor growth, with mean tumor inhibition ratio (TIR) being 65.08%, which was significantly higher than that of PTX plus GA plus HA treatment. In conclusion, PTX/HGAs demonstrated inhibitory effects tumor growth without unwanted side effects, suggesting that HGA conjugates hold a great potential as a delivery carrier for cancer chemotherapeutics to improve therapeutic efficacy and minimize adverse effects.
Animals ; Antineoplastic Agents ; administration & dosage ; adverse effects ; chemistry ; Apoptosis ; drug effects ; Drug Carriers ; chemistry ; Drug Delivery Systems ; instrumentation ; methods ; Drug Synergism ; Female ; Glycyrrhetinic Acid ; chemistry ; Hep G2 Cells ; Humans ; Hyaluronic Acid ; chemistry ; Male ; Mice ; Paclitaxel ; administration & dosage ; adverse effects ; chemistry

OBJECTIVETo compare the dissolution characteristics of colloidal silica and porous silica as the solid dispersion carrier, with baicalin as the model drug.

METHODThe baicalin solid dispersion was prepared by the solvent method, with colloidal silica and porous silica as the carriers. In the in vitro dissolution experiment, the solid dispersion was identified by scanning electron microscopy, differential scanning and X-ray diffraction.

RESULTThe solid dispersion carriers prepared with both colloidal silica and porous silica could achieve the purpose of rapid release. Along with the increase in the proportion of the carriers, the dissolution rate is accelerated to more than 80% within 60 min. Baicalin existed in the solid dispersion carriers in the non-crystalline form.

CONCLUSIONThe release behaviors of the baicalin solid dispersion prepared with two types of carrier were different. Among the two solid dispersion carriers, porous silica dissolved slowly than colloidal silica within 60 min, and they showed similar dissolutions after 60 min.

Calorimetry, Differential Scanning ; Colloids ; chemistry ; Drug Carriers ; chemistry ; Drug Delivery Systems ; instrumentation ; Flavonoids ; chemistry ; pharmacology ; Porosity ; Silicon Dioxide ; chemistry ; Solubility

The paeonol proniosomes ointment and ordinary ointment were administered to rats. Physiological saline served as perfused solution. The perfusion rate was 5 mL x L(-1) and the microdialysis samples were collected every 20 min intervals. The paeonol concentration in perfused solution was determined by HPLC. Investigation of the pharmacokinetics of paeonol proniosomes ointment and ordinary ointment by the skin-blood synchronous microdialysis coupled with HPLC is reported in this study. The results show that the recovery was (54.80 +/- 1.50)% in vitro and (54.58 +/- 4.61)% in vivo. The results showed that paeonol proniosomes ointment significantly raised the drug concentrations in skin more than the paeonol ordinary ointment. The paeono proniosomes ointment has less drugs into the blood as the ordinary ointments in blood, but its blood drug concentrations were steadier. The paeonol proniosomes ointment may be developed into a new preparation.
Acetophenones ; administration & dosage ; blood ; chemistry ; pharmacokinetics ; Animals ; Drug Delivery Systems ; instrumentation ; methods ; Drugs, Chinese Herbal ; administration & dosage ; chemistry ; pharmacokinetics ; Male ; Microdialysis ; Ointments ; administration & dosage ; chemistry ; pharmacokinetics ; Paeonia ; chemistry ; Rats ; Rats, Wistar ; Skin ; metabolism

Relatively uniform-sized nanoparticles made of poly (lactic-co-glycolic acid) (PLGA) were prepared by premix membrane emulsification method. After the drug loading property was completed, the dynamic tissue distribution of nanoparticles was recorded. With the average particle size and span as indexes, membrane pore size, number of passing membrane times, membrane pressure, volume ratio of oil-water phase and the concentration of poly(vinyl alcohol) (PVA) in external water phase were investigated by single factor test, the optimum preparation technology of blank PLGA nanlparticles was as following: pore size of SPG membrane was 1 μm, membrane pressure was 1. 15 MPa, the number of passing membrane time was 3, the mass fraction of PVA of 2%, volume ratio of oil-water phase of 1 : 5. Prepared nanoparticles were round with smooth surface, the mean diameter was 332.6 nm, span was 0.010, the confocal laser scanning microscope (CLSM) concluded that fluorescent substance is uniform composizion in PLGA nanoparticle, and the in vivo imaging technology in mice include that the nanoparticles show good liver and spleen targeting property.
Animals ; Drug Carriers ; chemistry ; Drug Delivery Systems ; instrumentation ; Emulsions ; chemistry ; Fluorescent Dyes ; chemistry ; Lactic Acid ; chemistry ; Mice ; Mice, Nude ; Nanoparticles ; chemistry ; Particle Size ; Polyglycolic Acid ; chemistry