Protective Effects of Nanoparticle-Loaded Aliskiren on Cardiovascular System in Spontaneously Hypertensive Rats.

Aliskiren, a renin inhibitor, has been shown to have cardioprotective and blood pressure (BP) lowering effects. We aimed to determine the effects of nanoparticle-loaded aliskiren on BP, nitric oxide synthase activity (NOS) and structural alterations of the heart and aorta developed due to spontaneous hypertension in rats. Twelve week-old male spontaneously hypertensive rats (SHR) were divided into the untreated group, group treated with powdered or nanoparticle-loaded aliskiren (25 mg/kg/day) and group treated with nanoparticles only for 3 weeks by gavage. BP was measured by tail-cuff plethysmography. NOS activity, eNOS and nNOS protein expressions, and collagen content were determined in both the heart and aorta. Vasoactivity of the mesenteric artery and wall thickness, inner diameter, and cross-sectional area (CSA) of the aorta were analyzed. After 3 weeks, BP was lower in both powdered and nanoparticle-loaded aliskiren groups with a more pronounced effect in the latter case. Only nanoparticle-loaded aliskiren increased the expression of nNOS along with increased NOS activity in the heart (by 30%). Moreover, nanoparticle-loaded aliskiren decreased vasoconstriction of the mesenteric artery and collagen content (by 11%), and CSA (by 25%) in the aorta compared to the powdered aliskiren group. In conclusion, nanoparticle-loaded aliskiren represents a promising drug with antihypertensive and cardioprotective effects.

A PLGA-PEG-PLGA Thermosensitive Gel Enabling Sustained Delivery of Ropivacaine Hydrochloride for Postoperative Pain Relief.

Postoperative pain is a complex physiological response to disease and tissue injury. Moderate-to-severe pain typically occurs within 48 h after surgery. Amino amide local anesthetics are widely applied to manage postoperative pain, and they have high efficacy, a low risk for addiction and limited side effects. However, these anesthetics also have short half-lives, often necessitating continuous injection to obtain satisfactory pain relief. In the current work, we used a poly(lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG)-PLGA (PLGA-PEG-PLGA) temperature-sensitive gel to deliver a local anesthetic, ropivacaine hydrochloride (RP), to prolong its analgesic effect. We investigated the influence of polymer and drug concentration on gelation temperature and the in vitro drug release rate from the temperature-sensitive gel. RP-loaded PLGA-PEG-PLGA solution is a liquid at room temperature and forms a gel at temperatures slightly lower than body temperature. With regard to the gel's drug release rate, 37.5, 51.3 and 72.6% of RP was released at 12, 24 and 48 h, respectively. This in vitro drug release profile conformed to the Higuchi equation. To assess pain control efficacy when using the gel, we evaluated the mechanical paw withdrawal reflex threshold, thermal pain threshold and incision cumulative pain scores in a rat incisional model. The results showed that the anti-pain effect of a single injection of RP-loaded gel at the incision site lasted for 48 h, which is significantly longer than the effect produced by injection of RP solution alone. The use of RP-loaded thermosensitive gels could provide a promising method for managing postoperative pain.

Effectiveness of Bupivacaine Liposome Injectable Suspension for Postoperative Pain Control in Total Knee Arthroplasty: A Prospective, Randomized, Double Blind, Controlled Study.

BACKGROUND: We compared the effectiveness of liposomal bupivacaine to ropivacaine, each as part of multimodal pain management, in total knee arthroplasty (TKA) postoperative pain control. METHODS: This prospective, double blind study randomized 96 TKA patients into a control group (periarticular injection of ropivacaine, ketorolac, morphine, and epinephrine in saline; 100cc) or an experimental group (periarticular injection of bupivacaine, ketorolac, morphine, and epinephrine in saline; 80cc plus 1.3% liposomal bupivacaine 20cc; total injection 100cc). The postoperative use of narcotics, visual analog pain scores, hours to ambulate 100 feet, and length of hospital stay were recorded. RESULTS: There was no significant difference between the two groups (control N = 49, experiment N = 47) in mean narcotic use per hour, total narcotic use during hospital stay, time to ambulate 100 feet, length of hospital stay, or visual analog score for pain postoperatively. CONCLUSION: There is no benefit in the use of liposomal bupivacaine compared with ropivacaine for postoperative pain control in TKA.

Post-PEGylation of siRNA Lipo-oligoamino Amide Polyplexes Using Tetra-glutamylated Folic Acid as Ligand for Receptor-Targeted Delivery.

For efficient and receptor-specific siRNA delivery, a new post-PEGylation strategy was established to provide siRNA polyplexes with targeting and shielding agents. For this purpose, core nanoparticles were formed by complexing siRNA with sequence-defined cationic lipo-oligomers. The T-shaped bis-oleoyl-oligoethanamino amides 454 and 595, containing stabilizing tyrosine and cysteine residues, were applied. These core nanoparticles were surface-shielded by reaction with maleimido-polyethylene glycol (Mal-PEG) reagents, optionally containing the targeting ligand folic acid (FolA). The PEGylation had two unpredicted consequences. First, FolA-PEG surface-modified polyplexes agglomerated due to the hydrophobicity of folic acid, resulting in ligand-independent gene silencing. This problem was solved by the use of tetra-γ-glutamyl folic acid (gE4-FolA) as targeting ligand. Post-PEGylated gE4-FolA siRNA polyplexes displayed sizes of 100-200 nm and mediated receptor specific uptake and effective gene silencing. Second, PEGylation triggered a destabilization of polyplexes, which was uncritical in cell culture but a limiting factor in vivo, as revealed by biodistribution studies in mice. This problem was partially overcome by selecting 595 (containing two CRC stability motifs) for polyplex core formation and an optimized lower degree of gE4-FolA PEGylation reagent. Biodistribution in L1210 tumor bearing mice demonstrated a significantly reduced lung signal and extended persistence of siRNA polyplexes (up to 8 h), with moderate delivery into the tumor. Further polyplex stabilization will be required for effective tumor-targeted delivery.

Proliposomal Ropivacaine Oil: Pharmacokinetic and Pharmacodynamic Data After Subcutaneous Administration in Volunteers.

BACKGROUND: Slow-release liposomal formulations of local anesthetics prolong plasma redistribution and reduce peak plasma drug concentration, allowing safer administration of larger doses and further prolonging sensory effects. However, their clinical applicability is limited by expensive manufacture and liposomal leakage. Previously, we described the simple preparation of a novel proliposomal ropivacaine oil that produces multilamellar liposomal vesicles on exposure to aqueous media and that has a shelf-life of >2 years at room temperature. In this study, we present both pharmacodynamic and pharmacokinetic data in healthy volunteers after subcutaneous injection of this novel proliposomal preparation of ropivacaine. METHODS: In the pharmacodynamic phase of this study, 15 volunteers received 3 separate subcutaneous injections of 2.5 mL containing 1 of the following drugs: proliposomal 4% ropivacaine, plain 0.5% ropivacaine, and the ropivacaine-free proliposomal vehicle. Drugs were administered into the lower back, and their location was randomized and blinded; a separate area was used as an uninjected, open control. Experimental sensory assessment was made at repeated intervals over 72 hours using both pinprick sensation and experimental heat pain tolerance (assessed using quantitative sensory testing). In a separate pharmacokinetic phase of this study, 9 volunteers received subcutaneous injections of 2.5 mL of either proliposomal 4% ropivacaine (n = 6) or plain 0.5% ropivacaine (n = 3); these participants had plasma ropivacaine concentrations assessed at repeated intervals over 72 hours. RESULTS: The mean ± SE duration of pinprick anesthesia after proliposomal and plain ropivacaine administration lasted 28.8 ± 6.0 and 15.9 ± 3.5 hours, respectively (mean difference, 16.8 hours; 95% confidence interval, 10.0-23.7; P = 0.001). For experimental heat pain, the anesthesia duration was approximately 36 and 12 hours, respectively, with mean ± SE area under the curve of the normalized heat pain tolerance over time 55.0 ± 28.8 Δ°C·min for proliposomal ropivacaine and 9.6 ± 26.0 Δ°C·min for plain ropivacaine (mean difference, 64.6 Δ°C·min; 95% confidence interval, 10.2-119.0; P = 0.036). In the pharmacokinetic study, there was no significant difference in peak plasma concentration in the proliposomal ropivacaine group (164 ± 43 ng/mL compared with 100 ± 41 ng/mL in the plain ropivacaine group; P = 0.07) despite an 8-fold increase in ropivacaine dose in the proliposomal group. The 99% upper prediction limit for peak plasma concentrations (351 ng/mL proliposomal; 279 ng/mL plain) was well below the putative toxic plasma concentration for both groups. The mean ± SE terminal half-life and area under the curve for proliposomal ropivacaine versus plain ropivacaine were 13.8 ± 3.6 hours vs 5.9 ± 2.3 hours (P = 0.011) and 5090 ± 1476 h·ng/mL vs 593 ± 168 h·ng/mL (P = 0.0014), respectively. CONCLUSIONS: The prolonged pharmacodynamic effect of proliposomal ropivacaine, together with its delayed elimination and prolonged redistribution to plasma, is compatible to depot-related slow-release and similar to the performance of other liposomal local anesthetics. The advantage of the proliposomal oil is its ease of preparation and its extended shelf-stability at room temperature.

A Novel Proliposomal Ropivacaine Oil: Pharmacokinetic-Pharmacodynamic Studies After Subcutaneous Administration in Pigs.

BACKGROUND: Liposomal local anesthetics are limited by a short liposomal shelf-life, even when under refrigeration. We describe a novel proliposomal ropivacaine that produces liposomes in situ, only after exposure to aqueous media. METHODS: In vitro: Nanoparticles were assessed (particle size distribution analyzer, cryo-transmission electron microscopy) at baseline and after exposure to saline/plasma. TOXICITY: In porcine wound healing study (n = 12), healing was assessed by photography, clinical assessment, and histology. Pharmacodynamics: Seventeen young piglets were randomly assigned to plain 0.5% ropivacaine (n = 5), proliposomal 4% ropivacaine (n = 6), or sham (n = 6). Tactile threshold was assessed using von Frey filaments applied to the surgical wound; the nonoperated skin was used as a control. Tactile threshold over time was determined using area under the curve (AUC) and assessed by 1-way analysis of variance. PHARMACOKINETICS: 8 young piglets were randomly assigned to plain 0.5% (25 mg, n = 4) or proliposomal 4% (200 mg, n = 4) ropivacaine. Plasma ropivacaine was assessed by high-performance liquid chromatography at baseline and at intervals over 36 hours. Paired ropivacaine concentration (from wound exudate and plasma) was obtained at 96 hours. Data were analyzed using noncompartmental and compartmental models. RESULTS: In vitro: On exposure to saline and plasma, the study drug was transformed from a homogenous oil to an emulsion containing liposomes of approximately 1.4-µm diameter; this effect was dilution dependent and stable over time. TOXICITY: All wounds healed well; no effect of drug group was observed. Pharmacodynamics: Plain and proliposomal ropivacaine provided sensory anesthesia for approximately 6 and 30 hours, respectively. There was an approximately 7-fold increase in the AUC of anesthesia for proliposomal ropivacaine compared with plain ropivacaine (mean difference, 1010; 95% confidence interval [CI], 625-1396 g·h/mm; P < 0.0001). PHARMACOKINETICS: There was no difference in Cmax (2.31 ± 0.74 vs 2.32 ± 0.46 mg/L), despite an approximately 8-fold difference in dose. However, proliposomal ropivacaine was associated with a marked prolongation of Tmax (6.50 ± 6.35 vs 0.5 ± 0.0 hours), terminal half-life (16.07 ± 5.38 vs 3.46 ± 0.88 hours; P = 0.0036), and ropivacaine-time AUC (47.72 ± 7.16 vs 6.36 ± 2.07 h·mg/L; P < 0.0001), when compared with plain ropivacaine. The proliposomal formulation provided an approximately 250-fold higher ropivacaine concentration in the surgical wound (mean difference, 3783 ng/mL; 95% CI, 1708-5858; P = 0.001) and an approximately 25-fold higher wound:plasma ropivacaine concentration ratio (mean difference, 126; 95% CI 38-213; P = 0.011). CONCLUSIONS: Proliposomal ropivacaine exerted prolonged anesthesia with delayed elimination, typical for liposomal drugs. The advantage of this novel proliposomal ropivacaine is its ease of preparation and its extended shelf-stability (>2 years) at room temperature.

Development of egg PC/cholesterol/α-tocopherol liposomes with ionic gradients to deliver ropivacaine.

CONTEXT: Ropivacaine (RVC) is an aminoamide local anesthetic widely used in surgical procedures. Studies with RVC encapsulated in liposomes and complexed in cyclodextrins have shown good results, but in order to use RVC for lengthy procedures and during the postoperative period, a still more prolonged anesthetic effect is required. OBJECTIVE: This study therefore aimed to provide extended RVC release and increased upload using modified liposomes. MATERIALS AND METHODS: Three types of vesicles were studied: (i) large multilamellar vesicle (LMV), (ii) large multivesicular vesicle (LMVV) and (iii) large unilamellar vesicle (LUV), prepared with egg phosphatidylcholine/cholesterol/α-tocopherol (4:3:0.07 mol%) at pH 7.4. Ionic gradient liposomes (inside: pH 5.5, pH 5.5 + (NH4)2SO4 and pH 7.4 + (NH4)2SO4) were prepared and showed improved RVC loading, compared to conventional liposomes (inside: pH 7.4). RESULTS AND DISCUSSION: An high-performance liquid chromatography analytical method was validated for RVC quantification. The liposomes were characterized in terms of their size, zeta potential, polydispersion, morphology, RVC encapsulation efficiency (EE(%)) and in vitro RVC release. LMVV liposomes provided better performance than LMV or LUV. The best formulations were prepared using pH 5.5 (LMVV 5.5in) or pH 7.4 with 250 mM (NH4)2SO4 in the inner aqueous core (LMVV 7.4in + ammonium sulfate), enabling encapsulation of as much as 2% RVC, with high uptake (EE(%) ∼70%) and sustained release (∼25 h). CONCLUSION: The encapsulation of RVC in ionic gradient liposomes significantly extended the duration of release of the anesthetic, showing that this strategy could be a viable means of promoting longer-term anesthesia during surgical procedures and during the postoperative period.

Periarticular Injection After Total Knee Arthroplasty Using Liposomal Bupivacaine vs a Modified Ranawat Suspension: A Prospective, Randomized Study.

BACKGROUND: The purpose of this study is to compare liposomal bupivacaine to a modified (Ranawat) local injection for total knee arthroplasty (TKA). METHODS: This is a prospective, randomized study of 105 consecutive patients undergoing primary TKA. Group A patients received a periarticular injection with liposomal bupivacaine and group B with a mixture of ropivacaine, epinephrine, ketorolac, and clonidine. There were 54 patients in the group A (liposomal bupivacaine) and 51 in group B. RESULTS: There were no differences in the groups with respect to age, sex, and preoperative knee scores. There were no differences with respect to postoperative narcotic usage and knee range of motion. CONCLUSION: Liposomal bupivacaine as a periarticular injection after TKA demonstrated similar pain levels, narcotic usage, and range of motion compared to a modified Ranawat suspension but improved walking distance.

Is There a Benefit for Liposomal Bupivacaine Compared to a Traditional Periarticular Injection in Total Knee Arthroplasty Patients With a History of Chronic Opioid Use?

BACKGROUND: Postoperative pain after total knee arthroplasty (TKA) poses a major challenge. It delays mobilization, increases opioid consumption and side effects, and lengthens hospitalization. This challenge multiplies when treating an opioid-dependent population. We examined whether a novel suspended release local anesthetic, liposomal bupivacaine (LB) would improve pain control and decrease opioid consumption after TKA compared to a standard periarticular injection in opioid-dependent patients. METHODS: Thirty-eight patients undergoing TKA were randomly assigned to receive either a periarticular injection (PAI) with LB (n = 20) or with a standard PAI (including a combination of ropivacaine, clonidine, Toradol, Epinepherine, and saline; n = 18) as part of a multimodal pain management approach. All periarticular injections were done by a single surgeon. Perioperative treatment was similar between groups. Postoperative information regarding pain level was evaluated by a pain visual analog scale score. Postoperative opioid consumption was recorded. RESULTS: After controlling baseline narcotic usage before surgery, no differences were found between groups in daily postoperative narcotic usage (P = .113), average daily pain score (P = .332), or maximum daily pain score (P = .881). However, when examining pain levels separately for each day, pain visual analog scale scores were reported higher in post operative day 1 in the LB group (P = .033). CONCLUSIONS: LB was not found to be superior to standard PAI in opioid-dependent patients undergoing TKA. This patient population continues to present a challenge even with modern multimodal pain protocols.

Epinephrine Affects Pharmacokinetics of Ropivacaine Infiltrated Into Palate.

Pulpal anesthesia success rates for ropivacaine following maxillary infiltration anesthesia seem to be low. We investigated the hypothesis that the addition of epinephrine would affect the pharmacokinetics of ropivacaine by retaining ropivacaine in the mucosa of the injected area through the time-dependent distribution of ropivacaine in the rat maxilla and serum following maxillary infiltration anesthesia using (3)H-labeled ropivacaine. We then examined the vasoactivity of ropivacaine with or without epinephrine on local peripheral blood flow. The addition of epinephrine to ropivacaine increased ropivacaine concentrations in the palatal mucosa and adjacent maxilla by more than 3 times that of plain ropivacaine at 20 minutes. By observing the autoradiogram of (3)H-ropivacaine, plain ropivacaine in the maxilla was remarkably reduced 20 minutes after injection. However, it was definitely retained in the palatal mucosa, hard palate, adjacent maxilla, and maxillary nerve after the administration with epinephrine. Ropivacaine with epinephrine significantly decreased labial blood flow. This study suggests that 10 µg/mL epinephrine added to 0.5% ropivacaine could improve anesthetic efficacy and duration for maxillary infiltration anesthesia over plain ropivacaine.

Rho-kinase inhibitor targeting the liver prevents ischemia/reperfusion injury in the steatotic liver without major systemic adversity in rats.

Rho-kinase (ROCK) inhibitors improve liver blood flow after ischemia/reperfusion (IR) injury, especially in the setting of steatosis, by decreasing the resistance of intrahepatic microcirculation through hepatic stellate cell (HSC) relaxation. However, the systemic administration of ROCK inhibitors causes severe hypotension; therefore, liver-specific ROCK inhibition is required. Here, we tested vitamin A (VA)-coupled liposomes carrying the ROCK inhibitor Y-27632 for targeted HSCs in steatotic rats. Rat livers with steatosis induced by a choline-deficient diet were subjected to IR injury. The delivery site and effect of the ROCK inhibitor were investigated. After liposomal Y-27632 injection, the survival rate after IR, the liver blood flow, the portal perfused pressure, and the hemodynamics were investigated. Immunohistochemical studies showed VA-coupled liposome accumulation in livers. Liposomal Y-27632 was 100-fold more effective in inhibiting HSC activation than free Y-27632. Liposomal Y-27632 improved the survival rate after IR injury, the liver blood flow, and the portal perfusion pressure without severe hypotension. In contrast, untargeted Y-27632 elicited severe systemic hypotension. We conclude that VA-coupled liposomes carrying the ROCK inhibitor yield enhanced drug accumulation in the liver and thus mitigate IR injury in the steatotic liver and reduce major systemic adversity.

Enzymatically and reductively degradable α-amino acid-based poly(ester amide)s: synthesis, cell compatibility, and intracellular anticancer drug delivery.

A novel and versatile family of enzymatically and reductively degradable α-amino acid-based poly(ester amide)s (SS-PEAs) were developed from solution polycondensation of disulfide-containing di-p-toluenesulfonic acid salts of bis-l-phenylalanine diesters (SS-Phe-2TsOH) with di-p-nitrophenyl adipate (NA) in N,N-dimethylformamide (DMF). SS-PEAs with Mn ranging from 16.6 to 23.6 kg/mol were obtained, depending on NA/SS-Phe-2TsOH molar ratios. The chemical structures of SS-PEAs were confirmed by (1)H NMR and FTIR spectra. Thermal analyses showed that the obtained SS-PEAs were amorphous with a glass transition temperature (Tg) in the range of 35.2-39.5 °C. The in vitro degradation studies of SS-PEA films revealed that SS-PEAs underwent surface erosion in the presence of 0.1 mg/mL α-chymotrypsin and bulk degradation under a reductive environment containing 10 mM dithiothreitol (DTT). The preliminary cell culture studies displayed that SS-PEA films could well support adhesion and proliferation of L929 fibroblast cells, indicating that SS-PEAs have excellent cell compatibility. The nanoparticles prepared from SS-PEA with PVA as a surfactant had an average size of 167 nm in phosphate buffer (PB, 10 mM, pH 7.4). SS-PEA nanoparticles while stable under physiological environment undergo rapid disintegration under an enzymatic or reductive condition. The in vitro drug release studies showed that DOX release was accelerated in the presence of 0.1 mg/mL α-chymotrypsin or 10 mM DTT. Confocal microscopy observation displayed that SS-PEA nanoparticles effectively transported DOX into both drug-sensitive and -resistant MCF-7 cells. MTT assays revealed that DOX-loaded SS-PEA nanoparticles had a high antitumor activity approaching that of free DOX in drug-sensitive MCF-7 cells, while more than 10 times higher than free DOX in drug-resistant MCF-7/ADR cells. These enzymatically and reductively degradable α-amino acid-based poly(ester amide)s have provided an appealing platform for biomedical technology in particular controlled drug delivery applications.

Ethosomes for skin delivery of ropivacaine: preparation, characterization and ex vivo penetration properties.

Ropivacaine, a novel long-acting local anesthetic, has been proved to own superior advantage. However, Naropin® Injection, the applied form in clinic, can cause patient non-convenience. The purpose of this study was to formulate ropivacaine (RPV) in ethosomes and evaluate the potential of ethosome formulation in delivering RPV transdermally. The RPV-loaded ethosomes were prepared with thin-film dispersion technique and the formulation was characterized in terms of size, zeta potential, differential scanning calorimetry (DSC) analysis and X-ray diffraction (XRD) study. The results showed that the optimized RPV-ethosomes displayed a typical lipid bilayer structure with a narrow size distribution of 73.86 ± 2.40 nm and drug loading of 8.27 ± 0.37%, EE of 68.92 ± 0.29%. The results of DSC and XRD study indicated that RPV was in amorphous state when encapsulated into ethosomes. Furthermore, the results of ex vivo permeation study proved that RPV-ethosomes could promote the permeability in a high-efficient, rapid way (349.0 ± 11.5 µg cm(-2) at 12 h and 178.8 ± 7.1 µg cm(-2) at 0.5 h). The outcomes of histopathology study forecasted that the interaction between ethosomes and skin could loosen the tight conjugation of corneocyte layers and weaken the permeation barrier. In conclusion, RPV-ethosomes could be a promising delivery system to encapsulate RPV and deliver RPV for transdermal administration.

Evaluation of New Fluorescent Lipophosphoramidates for Gene Transfer and Biodistribution Studies after Systemic Administration.

The objective of lung gene therapy is to reach the respiratory epithelial cells in order to deliver a functional nucleic acid sequence. To improve the synthetic carrier's efficacy, knowledge of their biodistribution and elimination pathways, as well as cellular barriers faced, depending on the administration route, is necessary. Indeed, the in vivo fate guides the adaptation of their chemical structure and formulation to increase their transfection capacity while maintaining their tolerance. With this goal, lipidic fluorescent probes were synthesized and formulated with cationic lipophosphoramidate KLN47 (KLN: Karine Le Ny). We found that such formulations present constant compaction properties and similar transfection results without inducing additional cytotoxicity. Next, biodistribution profiles of pegylated and unpegylated lipoplexes were compared after systemic injection in mice. Pegylation of complexes led to a prolonged circulation in the bloodstream, whereas their in vivo bioluminescent expression profiles were similar. Moreover, systemic administration of pegylated lipoplexes resulted in a transient liver toxicity. These results indicate that these new fluorescent compounds could be added into lipoplexes in small amounts without perturbing the transfection capacities of the formulations. Such additional properties allow exploration of the in vivo biodistribution profiles of synthetic carriers as well as the expression intensity of the reporter gene.

Catheter-based distal sciatic nerve block in patients with Charcot-Marie-Tooth disease.

BACKGROUND: The use of peripheral nerve blocks in patients with Charcot-Marie-Tooth (CMT) disease is scarcely reported; however, when performed it has proven to be effective for postoperative pain control. METHODS: A distal catheter-based sciatic nerve block for postoperative pain control was offered to 27 consecutive CMT patients scheduled for elective foot surgery. 18 of the 27 CMT patients consented to the offered sciatic nerve block. Localization of the sciatic nerve was guided by a nerve stimulator. The threshold current required to generate a motor response was assessed and a catheter inserted. Postoperative pain was assessed by recording the dose of analgesics to maintain visual analog score < 3 the next 48 hours. On demand patients received boluses of ropivacaine (2 mg/mL) via the catheter and/or analgesics in case of insufficient pain relief. Total postoperative ropivacaine dosage and analgesic consumption were recorded. About one year after the block patients were contacted to report their actual status by self-assessment. RESULTS: In 17 patients a catheter could be placed. In 7 patients placement of the catheter was difficult (several attempts, high electrical impedance). Patients with nerve block had lower analgesics consumption compared to patients without a block. Surprisingly, the 7 patients with "difficult" catheter-placement had the overall lowest ropivacaine and analgesics consumption compared to all other patients with or without peripheral block. No anesthesia related complications were reported by the questionnaire. CONCLUSIONS: In our small series catheter-based distal sciatic block within CMT patients had safely been used for pain relief up to three days. The infusion of local anesthetics via a catheter was not associated with any complication.

Ropivacaine via trans-cricothyroid membrane injection inhibits the extubation response in patients undergoing surgery for maxillary and mandibular fractures.

Extubation response can lead to cardiovascular and respiratory complications. Here, we aimed to evaluate the effect of ropivacaine injected via the trans-cricothyroid membrane on the extubation response. This prospective, double-blind, randomized study included 70 patients classified as American Society of Anesthesiologists status I-II, who required general anesthesia with nasotracheal intubation for maxillary and mandibular fracture surgery; patients were divided into the ropivacaine (20 mg) and dicaine (20 mg) groups. Both groups were injected via the trans-cricothyroid membrane. Mean arterial pressure (MAP), heart rate (HR), and incidence and severity of cough were recorded during intubation and extubation. During intubation, there was no significant intergroup difference in MAP or HR and no occurrence of coughing (P > 0.05). During extubation, MAP and HR were significantly lower in the ropivacaine group than the dicaine group (P < 0.05). The proportion of patients with no reports of cough was significantly higher in the ropivacaine group than in dicaine group (P < 0.05). The number of patients with grade 1 or 2 cough was significantly higher in the dicaine group than that in the ropivacaine group (P < 0.05). There was no significant intergroup difference in the rate of postoperative complications (P > 0.05). These results suggest that the administration of ropivacaine via trans-cricothyroid membrane injection can effectively inhibit the extubation response.

Liposomal bupivacaine versus traditional periarticular injection for pain control after total knee arthroplasty.

The purpose of this study was to compare a novel liposomal bupivacaine to traditional peri-articular injection (PAI) in a multi-modal pain protocol for total knee arthroplasty (TKA). A retrospective cohort study compared 85 consecutive patients undergoing TKA with a traditional PAI of ropivacaine, epinephrine and morphine to 65 patients with a liposomal bupivacaine PAI. After the initial 24h, inpatient self-reported pain scores were higher in the liposomal bupivacaine group compared to the traditional PAI group (P = 0.04) and a smaller percentage (16.9%) of patients in the liposomal bupivacaine group rated their pain as "mild" compared to the traditional group (47.6%). Liposomal bupivacaine PAI provided inferior pain control compared to the less expensive traditional PAI in a multi-modal pain control program in patients undergoing TKA.

Sustained release delivery of favipiravir through statistically optimized, chemically cross-linked, pH-sensitive, swellable hydrogel.

In the current work, favipiravir (an antiviral drug) loaded pH-responsive polymeric hydrogels were developed by the free redical polymerization technique. Box-Behnken design method via Design Expert version 11 was employed to furnish the composition of all hydrogel formulations. Here, polyethylene glycol (PEG) has been utilized as a polymer, acrylic acid (AA) as a monomer, and potassium persulfate (KPS) and methylene-bisacrylamide (MBA) as initiator and cross-linker, respectively. All networks were evaluated for in-vitro drug release (%), sol-gel fraction (%), swelling studies (%), porosity (%), percentage entrapment efficiency, and chemical compatibilities. According to findings, the swelling was pH sensitive and was shown to be greatest at a pH of 6.8 (2500%). The optimum gel fraction offered was 97.8%. A sufficient porosity allows the hydrogel to load a substantial amount of favipiravir despite its hydrophobic behavior. Hydrogels exhibited maximum entrapment efficiency of favipiravir upto 98%. The in-vitro release studies of drug-formulated hydrogel revealed that the drug release from hydrogel was between 85 to 110% within 24 h. Drug-release kinetic results showed that the Korsmeyer Peppas model was followed by most of the developed formulations based on the R2 value. In conclusion, the hydrogel-based technology proved to be an excellent option for creating the sustained-release dosage form of the antiviral drug favipiravir.

[Inferior alveolar nerve block with ropivacaine: effect on nausea and vomiting after mandibular osteotomy]. / Bloc du nerf alvéolaire inférieur par ropivacaïne : effets sur les nausées et vomissements en postopératoires (NVPO) des ostéotomies mandibulaires.

INTRODUCTION: Our objective was to evaluate the contribution of bilateral inferior alveolar nerve block (BIANB) in patients before mandibular sagittal osteotomy for postoperative pain management, consumption of opioids, treatment of nausea and vomiting. MATERIALS AND METHODS: We included 30 patients undergoing mandibular sagittal osteotomy in a prospective, randomized, double blind study. The first group of patients (n=14) underwent a standard procedure (general anesthesia with postoperative morphine treatment). The second group of patients (n=16) underwent BIANB before surgery, in addition to the standard procedure. The postsurgical management was evaluated every four hours for the first 24hours, according to the following criteria: postoperative nausea and vomiting (PONV), visual analogue scale (VAS) assessment of pain, consumption of morphine (cumulative dose) and antiemetic drugs, and need for releasing inter-maxillary blockage. RESULTS: PONV was significantly less frequent in the second group (6.3 % versus 42.9 %, P=0.031). The frequency of releasing inter-maxillary blockage and the consumption of antiemetic drugs were not significantly different in the two groups. The mean VAS pain score was significantly lower in the second group (1.6 versus 0.9 avec P=0.045). There was no significant difference in cumulative morphine requirements between the two groups at 24hours. DISCUSSION: BIANB during mandibular osteotomy increases the patient comfort by decreasing PONV and improving postsurgical analgesia.

[Percutaneous mandibular nerve block using neuro-stimulation guiding through the sigmoid indentation in facial surgery]. / Bloc percutané du nerf mandibulaire à travers l'échancrure sigmoïdienne, guidé par neurostimulation, en chirurgie de la face.

INTRODUCTION: Mandibular nerve block is a simple and effective but rarely used technique. It decreases peri-operative pain in mandibular osteotomy. It improves surgical field visibility by decreasing bleeding. Mandibular nerve block allows cutaneous surgery without general anesthesia and is one of the alternative treatments for chronic facial pain. TECHNICAL NOTE: The mandibular nerve is located using a needle connected to a neurostimulator. After local disinfection, a neurostimulation needle is inserted below the zygomatic arch, between the coronoid apophysis in front, and the condyle process in back, with a 45 to 60° angle. The needle is pushed to a 40 mm depth. Masticator muscle contraction confirms mandibular nerve stimulation. After a careful negative aspiration, 5 mL of ropivacaine 0.5% are injected slowly, and in increments. DISCUSSION: The complications with this technique, such as failure or arterial puncture, are rare and limited if a nerve stimulator is used. Patient's comfort is improved by intravenous remifentanil sedation in target control infusion mode, associated to prior use of prilocaine and lidocaine cutaneous cream.