Development of ropivacaine hydrochloride-loaded dissolving microneedles as a local anesthetic agent: A proof-of-concept.

Ropivacaine hydrochloride (RPL) is a local anesthetic agent that has been widely used for the treatment of pain during or after surgery. However, this drug is only available in parenteral dosage form and may contribute to the infiltration of RPL into the plasma, causing some undesirable side effects. Intradermal delivery of RPL using dissolving microneedles may become a promising strategy to deliver such drugs into the skin. This research aimed to develop RPL-loaded dissolving microneedles (DMN-RPLs) as a proof of the concept of intradermal delivery of a local anesthetic. The DMN-RPLs were fabricated using either centrifugation or air-pressurized chamber methods. Several polymers, such as poly(vinyl pyrrolidone) (PVP), poly(vinyl alcohol) (PVA), and sodium hyaluronate (SH), were utilized for manufacturing the DMN-RPLs. The prepared DMN-RPLs were assessed for their thermal properties, chemical bonds, mechanical strength, insertion ability, skin-dissolution study, and drug content. Furthermore, in-skin deposition and dermatokinetic studies were also performed. The results showed that F9 (30 % w/w PVP-4 % w/w SH) and F10 (30 % w/w PVP-5 % w/w PVA) containing 5 % w/w of RPL were the most promising formulations, as shown by their needle height reduction (<10 %) and insertion depth (∼400 µm). Both formulations were also able to deliver more than 60 % of the RPL contained in the DMNs into the epidermis, dermis, and receiver compartment. This study, for the first time, has provided a proof concept to deliver RPL as a local anesthetic using DMNs and the intradermal route, aiming to minimize pain and discomfort during administration and improve the patient's experience.

LC-MS/MS quantification of ropivacaine and local analgesic and adverse effects of Long-acting Ropivacaine Injection based on pharmacokinetic-pharmacodynamic modelling in Bama minipigs.

The local analgesic efficacy and adverse effects of a new Long-acting Ropivacaine formulation were examined based on pharmacokinetic-pharmacodynamic (PK-PD) modelling in Bama minipigs. 24 Bama minipigs, 12 males and 12 females, were randomly and equally divided into the following treatment groups: normal saline injection, drug vehicle injection, Long-acting Ropivacaine Injection and Ropivacaine Hydrochloride Injection. After routine disinfection, a skin incision about 3 cm long and 3 cm deep was produced in the leg of each pig, and mechanical withdrawal threshold (MWT) measured at various times pre- and post-injection as an index of analgesia against incision pain. Plasma ropivacaine concentrations were also measured at the same times using a novel liquid chromatography-tandem mass spectroscopy (LC-MS/MS) method. Minipigs were sacrificed 24 h post-injection and hearts collected for drug concentration measurements by LC-MS/MS. The LC-MS/MS method demonstrated high sensitivity, linearity and precision. The Long-acting Ropivacaine formulation produced a longer analgesic effect (∼12 h) at a lower plasma concentration than Ropivacaine Hydrochloride (∼4h), suggesting a better side-effects profile. A PK-PD model revealed a direct relationship between plasma ropivacaine concentration and MWT, with peak analgesia at about 1000 ng/mL and behaved good prediction ability. Long-acting Ropivacaine Injection is a superior local anaesthetic-analgesic treatment due to longer-lasting efficacy at lower concentrations compared to Ropivacaine Hydrochloride, which will reduce the risk of side effects such as cardiotoxicity.

Preparation of novel ropivacaine hydrochloride-loaded PLGA microspheres based on post-loading mode and efficacy evaluation.

Low encapsulation efficiency of the drug usually exist in hydrophilic drug which was embedded by hydrophobic materials directly in traditional method. In order to solve this problem, a novel preparation strategy which called "post-loading mode" was innovatively designed in this study: ropivacaine hydrochloride (ROP), a hydrophilic drug used in the field of anesthesia and analgesia, was encapsulated into the pre-prepared porous Poly (lactic-co-glycolic acid) (PLGA) microspheres; the porous PLGA microspheres (PLGA-Ms) with self-healing characteristic were used to obtain ROP-PLGA-Ms (with particle size around were 38 µm), in which drug loading (DL) was 8.72%. A rat sciatic nerve block model was established to evaluate the efficacy of ROP-PLGA-Ms. Exparel®, a bupivacaine liposome suspension approved by the FDA, was defined as reference agents in this study. The results showed that the injection of ROP, Exparel®, and ROP-PLGA-Ms were injected to the peripheral sciatic nerve could lead to motor dysfunction and sensory nerve block unanimously, and the onset time was less than 10 min for all cases. In addition, in comparison with ROP injection and Exparel®, the nerve block time of ROP-PLGA-Ms was significantly prolonged (P < 0.05). Effective analgesia duration of ROP-PLGA-Ms was about 5 h, 2.5 and 1.7 folds longer than that of ROP injection and Exparel®, respectively. The rats in each group could recover eventually within 8 h after administration. H&E showed that no inflammatory reaction was observed at the injection location. Analysis of blood biochemistry showed an insignificant difference between the microsphere experimental group and the negative group, which further indicated the safety of microsphere bioformulation.

[Effects of ropivacaine hydrochloride on the proliferation, invasion and apoptosis of osteosarcoma cells and its mechanism].

Objective: To investigate the effects and molecular mechanism of ropivacaine hydrochloride on osteosarcoma cell proliferation, invasion, and apoptosis. Methods: The osteosarcoma doxorubicin-resistant cell line (U2OS/DOX) was established by gradually increasing the drug doses. U2OS/DOX cells were treated with ropivacaine hydrochloride at the concentrations of 0, 20, 50 and 100 µg/ml, respectively; as different concentrations treatment groups of ropivacaine hydrochloride. pcDNA3.1 and pcDNA3.1-Livin were transfected into U2OS/DOX cells and then treated with 100 µg/ml ropivacaine hydrochloride, which were defined as ropivacaine hydrochloride 100 µg/ml+pcDNA3.1 group, ropivacaine hydrochloride 100 µg/ml+pcDNA3.1-Livin group. MTT was used to detect the cell proliferation inhibition rate and inhibitory concentration (IC50). Western blot was used to detect the expressions of cyclin-dependent kinase inhibitor 1A (P21) and activated cysteine aspartic protease-3 (Cleaved Caspase-3), E-cadherin, matrix metalloproteinase 2 (MMP-2) and Livin; clone formation experiments were used to detect the number of cell clones formed; flow cytometry was used to detect apoptosis; Transwell was used to detect cell migration and invasion; real-time fluorescent quantitative PCR (RT-qPCR) was used to detect Livin mRNA expression. Results: When the concentration of doxorubicin was more than 1 µg/ml, the proliferation inhibition rate of osteosarcoma cells U2OS was significantly increased in a concentration-dependent manner (P＜0.05); when the concentration of doxorubicin was more than 10 µg/ml, the proliferation inhibition rate of osteosarcoma resistant cell U2OS/DOX was significantly increased, and it was dose-dependent (P＜0.05). In U2OS/DOX cells treated with ropivacaine hydrochloride, the expressions of P21, Cleaved Caspase-3, and E-cadherin were increased significantly, the expression of MMP-2 was decreased significantly, the cell proliferation inhibition rate was increased significantly, the number of colony formation was decreased significantly, and the cells apoptosis rate was increased significantly, the number of cell migration and invasion was decreased significantly, and the expression of Livin was significantly reduced, in a concentration-dependent manner (P＜0.05). Overexpression of Livin partially reversed the inhibitory effect of ropivacaine hydrochloride on proliferation, migration, invasion, and promotion effect on apoptosis of cell U2OS/DOX. Conclusion: Ropivacaine hydrochloride can significantly inhibit the proliferation, migration and invasion of doxorubicin-resistant osteosarcoma cells, and significantly promote osteoma cell apoptosis. The mechanism may be related to Livin.

In vitro neurotoxicity by ropivacaine is reduced by silencing Cav3.3 T-type calcium subunits in neonatal rat sensory neurons.

Neurotoxicity of local anaesthetics has been alerted by more and more peoples. Cav3.1 and Cav3.2 T-type calcium channels were closely related with local anaesthetics toxicity. However, the role of Cav3.3, another subtype of the T-type calcium channel, on the neurotoxicity induced by local anaesthetics remains unclear. CaMKIIγ is a kind of multifunctional kinase and associated with a variety of physiological and pathological process. T-type calcium channel is closely related with CaMKIIγ. Up-regulation CaMKIIγ can increase T-type currents at the dorsal root ganglia (DRG). On the contrary, down-regulation results in the T-type currents decrease. Is the relation between Cav3.3 T-type channel calcium and CaMKIIγ involved with the ropivacaine hydrochloride neurotoxicity? In this study, we generated pAd-Cav3.3 and pAd-shRNA adenovirus vector to up-regulate and down-regulate Cav3.3 mRNA expression of the DRG. The cells treated or untreated with ropivacaine hydrochloride (3 mM) for 4 h were used to evaluate the neurotoxicity. Cell viability, cell death rate and apoptosis rate, Cav3.3 and CaMKIIγ expression were detected with MTT method, Hoechst-PI, flow cytometry, qRT-PCR and western blotting. Results showed that the cell viability of the DRG treated with ropivacaine hydrochloride markedly decreased, death rate and apoptosis rate, Cav3.3 and CaMKIIγ mRNA and protein expression significantly increased. Cav3.3 overexpression aggravated DRG injury induced by ropivacaine hydrochloride and inhibition of Cav3.3 expression improved the cell damages. Cav3.3 can regulate CaMKIIγ mRNA and protein expression. In conclusion, Cav3.3 regulated CaMKIIγ in DRG, which was involved with the cell injury induced by ropivacaine hydrochloride.

Effects of different concentrations of ropivacaine hydrochloride on lower limb nerve block anesthesia / 中国生化药物杂志

Objective To investigate the clinical effect of ropivacaine hydrochloride at 0.25%, 0.375% and 0.5% concentration for lower limb nerve block anesthesia.Methods75 cases of lower extremity nerve block anesthesia from Ningbo Zhenhai District Hospital of traditional Chinese Medicine from September 2014 to February 2015 were enrolled in the course of the study, they were divided into three groups: group 0.25%, the equivalent number of 0.375% and 0.5% groups, and three groups of patients were made with a concentration of 0.25%, 0.375%, 0.5% ropivacaine hydrochloride for lower extremity nerve block anesthesia;the clinical data of three groups were analyzed retrospectively, observation of three groups of patients with lower limb nerve block effect.ResultsThe results showed that 0.25% groups of patients in the motor block time was (36.8±5.9) minutes, motor block in patients with a total of 7 cases, with nerve block in patients with a total of 11 cases.0.375% groups of patients in the motor block time was (23.1±4.3) minutes, motor block in patients with a total of 14 cases, with nerve block in patients with a total of 18 cases.0.5% groups of patients in the motor block time was (20.6±5.7) minutes, motor block in patients with a total of 16 cases, with nerve block in patients with a total of 18 cases.Available block time of 0.375% groups of more than 0.5% groups, less than 0.25% groups;0.375% motor block group was 56.0%, higher than the 0.25% group, lower than the 0.5% group;the 0.375% group and 0.5% group of nerve block ratio is same, higher than the 0.25% group, the difference was statistically significant (P<0.05).ConclusionThe effect of anesthesia using concentration of 0.375% ropivacaine hydrochloride is relatively good, can reduce the dosage of anesthetic drugs, but also ensure the anesthetic effect, meet the clinical requirement, this method will be applied to.

The effects of ropivacaine hydrochloride on the expression of CaMK II mRNA in the dorsal root ganglion neurons.

In this study, we identified the subtype of Calcium/calmodulin-dependent protein kinase II (CaMK II) mRNA in dorsal root ganglion neurons and observed the effects of ropivacaine hydrochloride in different concentration and different exposure time on the mRNA expression. Dorsal root ganglion neurons were isolated from the SD rats and cultured in vitro. The mRNA of the CaMK II subtype in dorsal root ganglion neurons were detected by real-time PCR. As well as, the dorsal root ganglion neurons were treated with ropivacaine hydrochloride in different concentration (1mM,2mM, 3mM and 4mM) for the same exposure time of 4h, or different exposure time (0h,2h,3h,4h and 6h) at the same concentration(3mM). The changes of the mRNA expression of the CaMK II subtype were observed with real-time PCR. All subtype mRNA of the CaMK II, CaMK IIα, CaMK IIß, CaMK II δ, CaMK IIγ, can be detected in dorsal root ganglion neurons. With the increased of the concentration and exposure time of the ropivacaine hydrochloride, all the subtype mRNA expression increased. Ropivacaine hydrochloride up-regulate the CaMK IIß, CaMK IIδ, CaMK IIg mRNA expression with the concentration and exposure time increasing. The nerve blocking or the neurotoxicity of the ropivacaine hydrochloride maybe involved with CaMK II.

Formula Optimization of Ropivacaine Hydrochloride Transdermal Gel / 中国药师

Objective:To optimize the formula of ropivacaine hydrochloride transdermal gel. Methods:The steady transdermal rate and cumulative transdermal percentage in 24 h of ropivacaine hydrochloride gel were used as the indices, an orthogonal design was applied to select the optimal formula, and Design Expert 8. 0. 5. 0 software was used to analyze the results. Results: The optimal formula con-tained 2% carbomer, 10% propylene-glycol and 5% Azone. The steady transdermal rate of the optimal formula was 0. 6951 mg·h-1 · cm-2 . The cumulative transdermal percentage in 24 h of the optimal formula was 91. 04%, which was 22. 79% higher than that of ropiva-caine hydrochloride solution with the same concentration. Design Expert 8. 0. 5. 0 software could predict the steady transdermal rate and cumulative transdermal percentage in 24 h of the optimal formula. Conclusion: The preparation design is reasonable, and the gel has promising properties, which is suitable for skin local application.

Analgestic Effect of Scalp Nerve Block with Ropivacaine Hydrochloride at Different Time Points After Craniotomy / 医药导报

Objective To observe the effect of scalp nerve block ( SNB ) with ropivacaine hydrochloride at different time points on pain management after craniotomy. Methods Ninety patients undergoing craniotomy were randomly divided into 3 groups:group A, SNB conducted before surgery;group B, SNB conducted after surgery;group C, SNB conducted both before and after surgery, with 0. 5% of ropivacaine hydrochloride in each group. All patients received the same general anesthesia and diclofenac sodium were administered rectally as rescue analgesics. Sites and duration of surgeries, end-tidal sevoflurane concentration during incision, HR and SBP levels during the course of surgery and postoperative period, the VAS scores, GCS and Ramsay scores at 0. 5, 2, 4, 6, 12, 24, 48 h postoperatively, time of the first rescue appication analgesics and total consumption of rescue analgesics, the adverse effects, awareness under anesthesia were analyzed respectively, as well as local anesthesia relevant adverse events and time of wound healing. Results The end-tidal sevoflurane concentration was significantly decreased in group B (3. 19±0. 36)% as compared with group A (1. 81±0. 24)% and C (1. 77±0. 33)% (P0. 05);Compared with group A (600 mg), the consumption of rescue analgesics of group B (300 mg) and C (250 mg) were statistically lower (P0. 05);The relevant side effects were not different statistically, and there were no patients suffering from obvious awareness under anesthesia, pruritus, respiratory depression or local anesthesia relevant adverse effects. Conclusion SNB conducted before surgery can decrease the consumption of sevoflurane during incision, but has limited analgesic effects postoperatively. SNB conducted after surgery may provide transitional analgesia for neurosurgical patients undergoing craniotomy, while SNB conducted both before and after surgery does not show significantly longer analgesic time in postoperative pain management.

Determination of Content and Entrapment Efficiency of Ropivacaine Hydrochloride-loaded Multivesicular Liposomes / 中国药师

Objective:To establish a determination method for the content and entrapment efficiency of ropivacaine hydrochloride-loaded multivesicular liposomes. Methods: The separation of the multivesicular liposomes from the free drug was achieved by low-speed centrifugation. The concentration of ropivacaine hydrochloride in the supernatant and the multivesicular liposomes was determined by HPLC, and the entrapment efficiency was calculated. Results: The linear range of ropivacaine hydrochloride was 1. 0-80. 0μg· ml-1(r=0. 999 8). The average recovery was 99. 95% and RSD was 0. 72%(n=9). The content and entrapment efficiency of three batches of ropivacaine hydrochloride-loaded multivesicular liposomes was within the range of 99. 1%-100. 3% and 80. 06%-82. 14%, respectively. Conclusion:The method is simple and accurate, and can be used in the determination of content and entrapment efficien-cy of ropivacaine hydrochloride-loaded multivesicular liposomes.

Different effects of local anesthetics on extracellular signal-regulated kinase phosphorylation in rat dorsal horn neurons.

Local anesthetics, which are widely known to be neuronal voltage-gated Na(+) channel blockers, also affect a variety of other ion channels, N-methyl-d-asparate (NMDA) receptors and α-amino-3-hydroxy-5-methyl-4-izoxazolepropionic acid (AMPA) receptors. Glutamate, which is released from presynaptic fibers, activates extracellular signal-regulated kinase (ERK) through NMDA and AMPA receptors in spinal dorsal horn neurons. ERK plays a key role in central sensitization, which contributes to the chronicity of pain. We investigated the effects of four representative local anesthetics, lidocaine, tetracaine, levobupivacaine, and ropivacaine on ERK phosphorylation induced by capsaicin, which releases glutamate from presynaptic neurons, NMDA, AMPA, or ionomycin, a calcium ionophore, in dorsal neurons. We observed capsaicin-induced phosphorylation of ERK, which was suppressed by lidocaine, tetracaine, or ropivacaine, but not by levobupivacaine. NMDA-induced phosphorylation of ERK was suppressed by lidocaine, tetracaine, or levobupivacaine, but not by ropivacaine. AMPA-induced phosphorylation of ERK was suppressed by lidocaine or tetracaine, but not by levobupivacaine or ropivacaine. Finally, ionomycin-induced ERK phosphorylation was suppressed by lidocaine, tetracaine, or ropivacaine, but not by levobupivacaine. Our results suggest that local anesthetics contribute to the prevention of the incidence of persistent postsurgical pain with varying intensities and through different mechanisms of action.

Comparison of the efficacy and safety of ropivacaine mesylate and hydrochloride ropivacaine in epidural anesthesia / 中国基层医药

ObjectiveTo compare the effect and safety of ropivacaine mesylate with ropivacaine hydrochloride in epidural anesthesia of patients make hypogastric region and lower extremity operation.Methods126 patients with epidural anesthesia were divided into two groups,each group 63 cases.The observation group was administered with ropivacaine masylate,and the control group was administered with ropivacaine hydrochloride.The sense of pain block plane and effective-acting period and effect time,sports block rating and effect-acting period and duration,vital signs,adverse events and serious adverse events were observed.ResultsThere were no significant differences between the two groups on sense of pain block plane and effective-acting period and effect time,sports block rating and effect-acting period and duration,Bp,HR,SpO2,chang of ECG,bleeding in operation( t =13.23,10.52,10.64,12.21,13.23,10.52,10.64,12.21,6.11,5.34,5.23,6.05,all P ＞ 0.05 ).ConclusionThe results of ropivacaine mesylate used for anesthesia epidural was satisfied and had no obvious side effects as well as ropivacaine hydrochloride.

Intraperitoneal Ropivacaine Instillation for Postoperative Pain Relief after Laparoscopic Cholecystectomy

PURPOSE: A study was designed to assess the effect of intraperitoneal instillation of ropivacaine in larparoscopic cholecystectomy patients using computerized patient controlled anesthesia (PCA). METHODS: From January 2009 to June 2009, 40 patients with uncomplicated, symptomatic cholecystitis with cholelithiasis who were referred to Chung-Ang University Medical Center for laparoscopic cholecystectomy were included in the study. Patients in group C (control group) received normal saline 100 ml and those in group I (instillation group) received intraperitoneal instillation of 2 mg/kg of ropivacaine diluted in 100 ml saline at the initiation of pneumoperitoneum. Patients were assessed for pain by blinded investigators at 6 time intervals after surgery; 2 hr, 4 hr, 8 hr, 12 hr, 24 hr, and 48 hr. The frequency at which patients pushed the button of the PCA on bolus requirement (FPB) was assessed by a patient-controlled module on the PCA machine. RESULTS: The mean total fentanyl consumption was lower in group I (367.39+/-85.88) than in group C (535+/-100.29) during the 48 hours (P<0.001). Fentanyl velocity and FPB showed significant difference between the groups (P<0.005). Visual analogue scale (VAS) measured pain scores were significantly lower in group I than in group C at 4 hr (P=0.027), 8 hr (P=0.010), 12 hr (P=0.011). CONCLUSION: Intraperitoneal instillation of ropivacaine at the beginning of laparoscopic cholecystectomy (LC) combined with normal saline infusion is an effective method for reducing pain after LC.

Preparation of ropivacaine hydrochloride multivesicular liposomes and release in vitro / 中国药科大学学报

Aim: To prepare ropivacaine hydrochloride multivesicular liposomes, and to study the physicochemical properties and drug release behavior in vitro. Methods: Ropivacaine hydrochloride multivesicular liposomes were prepared by the multiple emulsion method. Single factor experiments were utilized to study the factors which affect the encapsulation efficiency of multivesicular liposomes. The formulation and pharmaceutical process were optimized by Box-Behnken experimental design, with the factors of encapsulation efficiency as the criteria. Three batches of the optimized multivesicular liposomes were prepared, and the encapsulation efficiency and in vitro release behavior were studied. Results: The particle size of the optimized multivesicular liposomes was uniform and 85% of them were well distributed in the range of 7-30 μm. The encapsulation efficiency was up to 90% when the ratios of lipid to drug, phospholipids to cholesterol and the amount of triolein was 1. 328:1(w/w) ,1.5: 1(w/ w) and 6 mmol/L, respectively. The release profile in vitro fitted to a first-order kinetics with the period of release up to 48 h in PBS buffer under 37 ℃. Conclusion: Ropivacaine hydrochloride multivesicular liposomes showed high encapsulation efficiency and significant sustained-release feature.