Active Systemic Anaphylaxis Test Research Articles

Chiral S-flurbiprofen axetil-loaded lipid microspheres for improved analgesic effects: Preparation, characterization, and preclinical evaluation

Flurbiprofen axetil (FPA) is a non-steroidal anti-inflammatory drug commonly used for managing post-surgical and cancer-related pain. However, FPA consists of two enantiomers, namely S-flurbiprofen axetil (S-FPA) and R-flurbiprofen axetil (R-FPA), with distinct inhibitory activities on cyclooxygenase (COX). This study focused on utilizing chiral S-FPA as the active pharmaceutical ingredient for the first time, and developed S-FPA-loaded lipid microspheres (S-FPA@LMs). The average particle size and zeta potential of S-FPA@LMs were 217.33 ± 6.66 nm and −36 ± 3.46 mV, respectively. S-FPA@LMs exhibited excellent stability for at least 6 months when stored at 5 ± 3 °C. COX activity inhibition assay revealed that S-FPA selectively inhibited COX-1, exhibiting a more potent inhibitory effect than the racemic form of FPA. In a rat model of postoperative incision pain, S-FPA@LMs demonstrated dose-dependent analgesic effects with superior efficacy compared to equimolar doses of FPA@LMs. Pharmacokinetic studies revealed comparable profiles for the metabolites, including S-flurbiprofen (S-FP) and R-flurbiprofen (R–FP), when S-FPA@LMs and FPA@LMs were administered in equimolar doses. Additionally, continuous administration for 7 days showed no significant accumulation of S-FP and R–FP. The inversion from S-FP to R–FP after S-FPA@LMs administration was also negligible. In terms of safety, S-FPA@LMs did not induce any signs of hemolysis or coagulation in rabbit erythrocytes. Moreover, no immediate allergic reactions were observed in the active systemic anaphylaxis test. The sub-acute toxicity study indicated dose-dependent adverse reactions primarily related to the gastrointestinal system, with recovery observed after a 2-week recovery period. Notably, S-FPA@LMs displayed a lower mortality rate and less severe pathological changes in the deceased rats compared to FPA@LMs. Overall, our findings highlight the potential of S-FPA@LMs as a promising candidate for acute pain management with satisfactory stability, enhanced analgesic efficacy, reduced dosage, and reduced toxicity compared to the racemic mixture. In summary, the introduction of S-FPA@LMs presents an innovative approach to managing acute pain, warranting further exploration and development in the field of pain therapeutics.

Systemic and Local Anaphylaxis is Not Induced by Korean Red Ginseng Mixture in Guinea Pigs

Currently, injuries to customers due to health functional foods are annually increasing. To evaluate the antigenicity of Korean red ginseng mixture (KRGM), we tested for systemic anaphylactic shock and passive cutaneous anaphylaxis in guinea pigs. Based on a comparison of measured body weights, there were no changes in body weight for the KRGM treatment group compared with the control group. In the ovalbumin treated group, however, there was a statistically significant decrease in body weight. For the active systemic anaphylaxis test, after the induction, there were no symptoms that suggested anaphylactic shock in the control and KRGM treatment group. In the ovalbumin treated group, there were symptoms that suggested severe anaphylaxis, and those symptoms included restlessness, piloerection, tremor, rubbing or licking the nose, sneezing, coughing, hyperpnea, dyspnea, staggering gait, jumping, gasping and writhing, convulsion, side position and Cheyne-stokes respiration. All animals died within thirty minutes in the ovalbumin treated group. For the passive cutaneous anaphylaxis test in guinea pigs sensitized to KRGM, each anti-serum was diluted in a stepwise manner. This was followed by an intravenous injection of a mixture of KRGM and Evans blue. The results of the test showed that all the responses were negative in the control and the low-dose and high-dose administration groups. However, in the ovalbumin treated group, all the responses were positive. Based on the above results, there were no anaphylactic responses for up to 12 times the amount of human intake of KRGM in Hartley Guinea-pigs. The results suggest that KRGM is safe as measured by the systemic and local antigenicity in guinea pigs.

Preclinical evaluation of the safety and pathogenicity of a live attenuated recombinant influenza A/H7N9 seed strain and corresponding MF59-adjuvanted split vaccine.

Developing a safe and effective H7N9 influenza vaccine was initiated in early spring 2013, following human infections with a novel avian influenza A (H7N9) virus. In this study, a candidate H7N9 vaccine seed strain is produced using reverse genetics, with HA and NA derived from a human H7N9 virus and the remaining genes from the PR8 backbone virus which grows well in eggs. We verified that the virulence and transmissibility of the recombinant H7N9 vaccine seed strain were decreased as compared to wild-type H7N9 virus, to levels comparable with PR8. Using the seed virus, we produced a monovalent split influenza A (H7N9) MF59-adjuvanted vaccine that was immunogenic in mice. Our H7N9 vaccine is selected for clinical investigation and potential human use. To assess the safety of our H7N9 vaccine, we performed acute toxicity, repeated dose toxicity and active systemic anaphylaxis tests. Our results showed that, under the conditions used in this study, the NOEAL (no obvious adverse effect level) was 30 μg/0.5 mL.

Preparation, Characterization and Related <i>in Vivo</i> Release, Safety and Toxicity Studies of Long Acting Lanreotide Microspheres

The goal of this project was to prepare long-acting lanreotide acetate poly(lactic-co-glycolic acid) (PLGA) microspheres and to analyze the in vivo and in vitro release, safety and toxicology of these preparations. Long-acting lanreotide acetate PLGA microspheres that exhibited a 5-week slow-release period were prepared by a multiple-emulsion solvent evaporation method. Physical characterization, as well as the analysis of the in vivo and in vitro release, safety, acute toxicity and chronic toxicity of the lanreotide microspheres, were conducted in animal models in rats, guinea pigs, rabbits and beagle dogs. The lanreotide acetate PLGA microspheres prepared by multiple-emulsion solvent evaporation had smooth surfaces, uniform particle size and stable lanreotide loading. In vivo and in vitro experiments showed that the lanreotide acetate PLGA microspheres could continuously release lanreotide for 5 weeks. The safety of these long acting lanreotide microspheres was good in the following animal models: active systemic anaphylaxis test in guinea pigs, passive cutaneous anaphylaxis test in rats, hemolytic test in rabbits, local skin irritation test after subcutaneous administration in rabbits and muscle stimulation test in rabbits. Furthermore, no significant acute toxicity or chronic toxicity was observed after administration of lanreotide acetate PLGA microspheres in beagle dogs at dosages up to 22 mg/kg. The lanreotide acetate PLGA microspheres that were prepared in this study exhibited beneficial characteristics in apparent property and structural stability, as well as in release trends in vivo and in vitro.

Antigenicity tests of a new antineoplastic agent S-1

The antigenicity was tested of a new antineoplastic agent S-1 (a combination of tegafur (FT), CDHP and potassium oxonate (Oxo)) in mice and guinea pigs. 1. Male BALB/c or C3H/He mice were sensitized with S-1, CDHP, Oxo, and conjugates of CDHP (or Oxo) and human serum albumin (HSA). S-1 was administered by oral gavage, and the other compounds were administered intraperitoneally with adjuvant (alum). In the heterologous passive cutaneous anaphylaxis (PCA) test, using Sprague-Dawley rats as recipients, no IgE antibodies against S-1, CDHP, or Oxo were detected to any serum obtained from the sensitized mice, and no eliciting antigenicities were seen for CDHP or Oxo. 2. Male Hartley guinea pigs were sensitized with S-1, CDHP, Oxo, and conjugates of CDHP (or Oxo) and HSA. S-1 was administered by oral gavage, and the other compounds were administered subcutaneously with Freund's complete adjuvant (FCA). The homologous PCA test, active systemic anaphylaxis test, and passive hemagglutination test showed no production of antibodies against S-1, CDHP, or Oxo in any sensitized guinea pig, and no eliciting antigenicities for CDHP or Oxo. 3. Female Hartley guinea pigs were sensitized with S-1 subcutaneously with FCA. The active cutaneous anaphylaxis test revealed that S-1 did not induce cell-mediated delayed type hypersensitivity. 4. These results indicated that S-1, Oxo, and CDHP were not antigenic in mice and guinea pigs.

Preclinical Pharmacokinetics and General Toxicology of Iodixanol

To document the safety of iodixanol and to assess its pharmacokinetic properties, extensive tests have been performed. Iodixanol was rapidly excreted, mainly via the kidneys, with a plasma half-life in rats and monkeys of 25 and 76 mins, respectively. The pharmacokinetic data were consistent with an extracelleular distribution of iodixanol. During the 24 hours post-dosing, the urinary excretion was from 72 to 100% in rats, and 78% in monkeys. Biliary excretion was 1.5% during the first 4 hours in rats. Fecal excretion was about 7% in rats and 0.8% in monkeys over the first 24 hours after injection. Approximately 0.5 and 1% of the dose was found in the kidneys of rats and monkeys, respectively, 24 hours after dosing. Acute toxicity of iodixanol in rats was low, with an LD(50) greater than 21 g I/kg. In mice the LD(50) was 21 g I/kg and the approximated median lethal dose (ADL(50)) was found to range from 15 to 21 g I/kg. A single dose of 1 and 3 g I/kg was well tolerated in monkeys. As for the other roentgen contrast media, a reversible, dose-related, vacuolation of the proximal tubules in the kidneys was seen in the acute and subacute studies in rats and monkeys. No relationship was seen between the vacuolation and kidney function. Local tolerance studies demonstrated a low irritation potential for iodixanol when injected by a variety of intravascular and extravascular routes. The reproductive capacity of male and female rats was unaffected by iodixanol when administered daily at doses up to 2 g I/kg/day. No teratogenic potential in rats and rabbits of iodixanol was observed. Further, no toxic effects on pups were seen when rats were dosed during the lactation period. Each of 4 standard genotoxicity tests was negative. No antigenic potential of iodixanol was observed when assessed by the passive cutaneous anaphylaxis test and the active systemic anaphylaxis test in guinea pigs. The intravascular tolerability of iodixanol is high, and therefore, iodixanol should be considered as a safe roentgen contrast medium for intravascular use.

Antigenicity study on montirelin hydrate (NS-3)

An antigenicity study of montirelin hydrate (NS-3), a new drug for the treatment of disturbance of consciousness, was conducted in Hartley guinea pigs. Animals were sensitized twice by subcutaneous injections of montirelin hydrate in combination with Freund's complete adjuvant and twice by intramuscular injections of montirelin hydrate alone. Montirelin hydrate was found to be negative in the homologous passive cutaneous anaphylaxis test carried out with sera from the sensitized guinea pigs. Negative results were also obtained in the active cutaneous anaphylaxis test and the active systemic anaphylaxis test in guinea pigs sensitized with montilerin hydrate. These results show that montirelin hydrate has no antigenicity under the present experimental conditions.

The radioimmunoassay of histamine release from circulating basophils in an in vitro study as support for the in vivo active systemic anaphylaxis test in the guinea pig

An in vitro anaphylaxis test is described which explores the ability of compound re-challenge to induce histamine release from polynuclear basophils in whole blood of guinea pigs that had previously been sensitised. This test is used in drug safety, in support of the in vivo active systemic anaphylaxis test, which is sometimes required by regulatory authorities, when the observed clinical signs are not conclusive. This sensitive and discriminative test is inexpensive and reduces animal utilisation.

Antigenicity of penicillin G in the guinea pig

Antigenicity of penicillin G (PCG) was studied in guinea pigs. PCG 5 mg, 10 mg or 25 mg with Freund's complete adjuvant each on days 0, 7 and 21 was injected to a guinea pig: intramuscularly into both thighs and intracutaneously into four locations on the back. A remarkable antigenicity was induced in animals immunized with 25 mg although only low antigenicity in 5 mg and 10 mg. A maximum serum level of the antibody was observed about 2 weeks after last immunization and all of animals immunized with 25 mg died in active systemic anaphylaxis test. As mentioned above, it has been firstly demonstrated that a remarkable antigenicity of PCG can be produced by immunizing with a high dose of 25 mg in the guinea pig model in which PCG itself is used as immunogen.