Recent trends in vaccine delivery systems: A review.

Vaccines are the preparations given to patients to evoke immune responses leading to the production of antibodies (humoral) or cell-mediated responses that will combat infectious agents or noninfectious conditions such as malignancies. Alarming safety profile of live vaccines, weak immunogenicity of sub-unit vaccines and immunization, failure due to poor patient compliance to booster doses which should potentiate prime doses are few strong reasons, which necessitated the development of new generation of prophylactic and therapeutic vaccines to promote effective immunization. Attempts are being made to deliver vaccines through carriers as they control the spatial and temporal presentation of antigens to immune system thus leading to their sustained release and targeting. Hence, lower doses of weak immunogens can be effectively directed to stimulate immune responses and eliminate the need for the administration of prime and booster doses as a part of conventional vaccination regimen. This paper reviews carrier systems such as liposomes, microspheres, nanoparticles, dendrimers, micellar systems, ISCOMs, plant-derived viruses which are now being investigated and developed as vaccine delivery systems. This paper also describes various aspects of "needle-free technologies" used to administer the vaccine delivery systems through different routes into the human body.

Niosomal methotrexate gel in the treatment of localized psoriasis: phase I and phase II studies.

BACKGROUND: Efficacy of topical methotrexate in psoriasis is limited by its penetration. AIMS: The study involved the preparation of niosomal methotrexate in chitosan gel and to test the same for irritation and sensitization on healthy human volunteers followed by assessing the efficacy of the gel through double-blind placebo-controlled study on psoriasis patients and also comparing its efficacy with a marketed methotrexate gel. METHODS: The methotrexate niosomes were prepared by lipid layer hydration method. The characterized niosomes were incorporated in chitosan gel. The gels were tested on 10 human volunteers to check for irritation and skin sensitivity by human repeated insult patch test (HRIPT). The formulations were assessed for efficacy by double-blind placebo-controlled study in 10 psoriasis patients for each formulation. The efficacy was calculated by psoriasis area and severity index scoring method. The global score was used to assess the progress of the disease. RESULTS: The HRIPT test did not produce any significant irritation or sensitization on healthy human volunteers. The placebo and marketed gels were compared with niosomal methotrexate gel. At Week 12, with niosomal methotrexate gel, there was reduction in total score from 6.2378+/-1.4857 to 2.0023+/-0.1371. CONCLUSION: These results suggest that niosomal methotrexate gel is more efficacious than placebo and marketed methotrexate gel.

Gastric leiomyoma presenting as gastric volvulus.

We report a 45-year-old lady who presented with recurrent vomiting, retching and epigastric pain, and was diagnosed to have gastric volvulus. After correction of the volvulus by endoscopic detorsion, a tumor was seen along the greater curvature. This was excised surgically. Histology showed leiomyoma.