Safety and efficacy of water-in-oil-in-water emulsion vaccines containing Newcastle disease virus haemagglutinin-neuraminidase glycoprotein

Subunit vaccines containing haemagglutinin-neuraminidase (HN) glycoprotein of Newcastle disease virus (NDV), formulated as water-in-oil-in-water (W/O/W) emulsions, were prepared. First, the suitable constituents of a W/O/W emulsion adjuvant were investigated with polyvalent vaccines using NDV, infectious bronchitis virus and Haemophilus paragallinarum. The W/O/W emulsion adjuvant, composed of the antigen in phosphate-buffered saline (PBS), liquid paraffin, squalene, diglyceryl monooleate, polysorbate 80 and PBS in a 30:25:10:5:2:28 ratio, induced a good antibody response with less adverse local reactions. HN protein of NDV was expressed by an improved baculovirus expression vector, a hybrid nucleopolyhedrovirus (HyNPV) between Autographa californica NPV and Bombyx mori NPV,and was prepared from silkworm pupae infected with the recombinant baculovirus, HyNPV-HN. Then, the W/O/W emulsion vaccine containing HN protein was prepared using the aforementioned constituents. Chickens showed 100, 100 and 80% protection against challenge exposure to virulent NDV at 4 weeks after vaccination with W/O/W emulsion vaccines containing 30, 6 and 3% of HyHPV-HN-infected pupae, respectively. The vaccines containing HN protein did not induce adverse local reactions at the site of injection. The subunit vaccine for NDV containing HN protein expressed in the recombinant baculovirus-infected pupae, formulated as a W/O/W emulsion vaccine composed of the antigen in PBS, liquid paraffin, squalene, diglyceryl monooleate, polysorbate 80 and PBS in a 30:25:10:5:2:28 ratio, was therefore found to be safe and effective.

Effect of liquid paraffin on antibody responses and local adverse reactions of bivalent oil adjuvanted vaccines containing newcastle disease virus and infectious bronchitis virus

Effects of liquid paraffin on antibody responses and local adverse reactions after intramuscular injection of oil adjuvanted vaccines containing Newcastle disease (ND) and infectious bronchitis (IB) virus were investigated in chickens. Each vaccine was prepared with a liquid paraffin such as Carnation, Crystol 52 and Lytol. These vaccines induced sustained antibody responses against ND and IB. Among local adverse reactions, Lytol induced granulomatous reactions and abscesses, but Carnation and Crystol 52 did not. The residual weight of liquid paraffin at the injection site decreased in the order Carnation, Crystol 52, Lytol. Crystol 52 was composed of relatively few short-chain hydrocarbons (i.e., <n-C16H34) and long-chain hydrocarbons (i.e., >n-C20H42). The vaccine with liquid paraffin mainly composed of n-C16H34-n-C20H42 was suggested to induce fewer adverse reactions.

Relationship between antigen release and antibody response of infectious coryza water-in-oil-in-water emulsion vaccines

The relationship between the antigen release from formulations in vitro and the antibody response after administration of water-in-oil-in-water (W/O/W) emulsion vaccines containing Haemophilus paragallinarum (Hpg) was studied in chickens. Increases of sorbitan sesquioleate volume in the formulation led to slower antigen release and tended to induce higher hemagglutination-inhibition (HI) antibody titers. In addition, the vaccines prepared with internal aqueous phase:oil phase:external aqueous phase (A:O:A) ratios of 3:4:3 and 3:3:4 also showed slower release of antigen and higher HI antibody titer compared with those of an A:O:A ratio of 3:2:5. Vaccines prepared with polyoxyethylene (POE)(10) hydrogenated castor oil or POE(40) hydrogenated castor oil instead of sorbitan sesquioleate showed higher release and lower antibody HI titers. As a result, HI antibody titers at 6 wk after vaccination were inversely related to antigen release, as determined by the release test. The correlation coefficient was 0.942. In infectious coryza W/O/W emulsion vaccines, the slow release of antigen from the formulation induced and maintained high HI antibody titers of Hpg.

Relation between antigen release and immune response of oil adjuvanted vaccines in chickens

The relationship between release properties of the model antigen, bovine serum albumin (BSA), from formulations in vitro and immune response after administration of various oil adjuvanted vaccines containing liquid paraffin was examined in chickens. The vaccine prepared at an hydrophile-lipophile-balance (HLB) number of 4.8 showed slower release of BSA and higher immune response on injected chickens than that with an HLB number of 6.0. Decreases of aqueous volume ratio in the formulation also led to slower release of BSA and higher immune response. The slower release rate of BSA showed higher ELISA antibody titer even at 20 weeks after vaccination. The ELISA antibody titer inversely was related to the constant release rate, k, calculated from the in vitro release test. The correlation coefficient was 0.863. The immune response of oil adjuvanted vaccines containing Haemophilus paragallinarum agreed well with these results with BSA. Our results indicated that a stronger and more prolonged immune response of oil adjuvanted vaccines was achieved by slower release rate of antigen from the formulation. In addition, there was a good correlation between immune response and the value of k.

Design of a polyvinyl alcohol hydrogen containing phospholipid as controlled-release vehicle for rectal administration of (+/-)-propranolol HCl

Polyvinyl alcohol hydrogels which contained phospholipid, egg yolk lecithin or hydrogenated soya lecithin were designed as a transrectal delivery system for propranolol hydrochloride. The hydrogel preparations containing phospholipid were prepared by a low-temperature crystallization method. The release profile of propranolol from hydrogel preparations containing phospholipid complied with Fickian diffusion (Higuchi model). The release of propranolol from the hydrogel preparation decreased with higher contents of phospholipid (approximately 2% w/w). In rats plasma concentrations of propranolol after rectal administration of hydrogel preparations containing phospholipid (1 and 2% w/w) were prolonged compared with those of rats receiving preparations without phospholipid.

Design of polyvinyl alcohol hydrogel as a controlled-release vehicle for rectal administration of dl-propranolol-HCl and atenolol

Preparations of beta-blockers, propranolol-HCl and atenolol, in poly(vinyl alcohol) (PVA) hydrogel were designed for the therapeutic treatment of hypertension by transrectal delivery. In vitro release characteristics and plasma drug concentration profiles after rectal administration in rats and dogs were examined. The PVA hydrogels containing beta-blockers were prepared by a low-temperature crystallization method. The release of beta-blockers from hydrogel preparations was consistent with Fickian diffusion (Higuchi model); the drug release versus the square root of release time profile gave a straight line over 60% of the total release process. The release of beta-blockers from hydrogel preparations increased at higher concentrations of PVA in the hydrogel preparations and was not affected by the pH of hydrogel preparations. Plasma concentrations of beta-blockers after rectal administration of hydrogels were higher than those after administration of suppositories (Witepsol H-15) in rats and dogs. The drug plasma concentrations increased at higher concentrations of PVA in hydrogel preparations. In the case of propranolol, which is a hepatic high-clearance drug, area under the blood concentration curve, 0-8 h after rectal administration of a hydrogel preparation (20% w/w PVA, pH 7.0) was 2.16 times and 5.26 times higher than those obtained with Witepsol H-15 suppository and oral administration, respectively. Rectal administration with PVA hydrogels is a favorable route for a hepatic high-clearance drug such as propranolol.

Evaluation of polyvinyl alcohol hydrogel as a sustained-release vehicle for rectal administration of indomethacin

In order to evaluate an indomethacin polyvinyl alcohol (PVA) hydrogel for rectal administration, the in vitro release characteristics of indomethacin from the hydrogel and indomethacin plasma concentrations after rectal administration were examined. The PVA hydrogel containing indomethacin was prepared by a low-temperature crystallization method. The release of indomethacin from the PVA hydrogel agreed with the Fickian diffusion model for 10 hr. Rectal administration of indomethacin hydrogels to rats yielded high indomethacin plasma concentrations, without producing a sharp peak, and a sustained-release effect. In dogs, the indomethacin hydrogel produced a similar sustained-release effect; however, the indomethacin plasma concentration was relatively low compared with that of an indomethacin suppository.