JP-2021529217-A5 -

Dates

Publication Date

20221201

Application Date

20190626

Description

The present invention relates to a drug delivery capsule, which is a novel form of drug delivery system for delivering active ingredients such as drugs to biological tissue by being directly inserted into the subcutaneous tissue or muscle in a capsule shape. More specifically, the present invention relates to a subcutaneous bioabsorbent drug delivery capsule having an internal space for containing an active ingredient such as a drug, and an external casing made of a bioabsorbent material, which has a function to ensure that drug delivery begins only after a predetermined amount of time has elapsed. The term "vaccine" originates from the Latin word "vacca," meaning "cow," which Jenner borrowed when he discovered the cowpox vaccine. The immunity that can be obtained through successful vaccination includes two types: humoral immunity (antibody-mediated immunity) and cellular immunity (cell-mediated immunity). In other words, the goal of vaccination is not only to induce humoral immunity, which is the ability to immediately respond to the next invasion of the pathogen after antibodies are produced upon vaccination, but also to induce cellular immunity, which involves remembering the pathogen as an antigen and, upon invasion, inducing the action of T lymphocytes that directly attack the pathogen by releasing phagocytic cells and inflammatory substances called cytokines. The immunity acquired through antibodies received from the mother immediately after birth, and the immunity obtained by administering antiserum containing antibodies, are passive immunity and provide only temporary effects. In contrast, immunity induced by vaccines is active immunity because it allows the immune system to "remember" the pathogen. Such vaccines are insufficient with just one dose because their antibody-forming effect is diminished. Complete immunity requires two or three (or more) doses. This applies to both whole-cell vaccines (using the entire pathogen) and cellulose or subunit vaccines (using only a portion of the pathogen). Most vaccines are whole-cell vaccines, which are further classified as either inactivated vaccines (where the pathogen is inactivated to prevent pathogenicity) or attenuated vaccines (live vaccines). Inactivated vaccines, where the vitality of the pathogenic microorganism is removed using chemicals or radiation, have the advantage of being stable and unlikely to reactivate in the human body. However, they are less effective and require several booster shots. On the other hand, live vaccines involve culturing pathogenic microorganisms in extreme environments or culturing them while continuously transferring them to different hosts to weaken their toxicity. While they may potentially induce the disease in immunocompromised individuals by restoring pathogenicity, they have the advantage of requiring fewer doses to achieve complete antibody formation compared to inactivated vaccines. In other words, with the exception of some cases such as oral formulations for infants like the oral polio vaccine, vaccines are generally administered via intramuscular injection, which is a predetermined route of administration. However, for those receiving the vaccine, this unusual injection method involves the inconvenience of having to receive several doses at intervals of several months to several years. Aside from the inconvenience to those receiving the vaccine, large-scale livestock farms raising dozens or hundreds of animals face significant problems with infectious diseases. Therefore, multiple vaccinations at appropriate intervals based on each animal's age (weeks or months) are recommended or even mandated, but this is extremely cumbersome and difficult. For example, in the case of foot-and-mouth disease, which repeatedly infects cattle, pigs, goats, and deer over long periods and causes problems, prevention is possible by administering the foot-and-mouth disease vaccine two or more times. However, managing multiple vaccinations at precise intervals for each individual animal is not only difficult in terms of vaccination management itself, but also carries the risk of safety accidents when administering two or more vaccinations to large numbers of livestock that are older and more robust, several weeks to several months after the initial vaccination. Therefore, there is a need for a technology that allows livestock at a young age (weeks or months) to develop sufficient antibodies with just one vaccination, eliminating the need for booster shots. However, no suitable solution has yet been proposed. As one such solution, the inventors have been researching active ingredient delivery capsules using bioabsorbent materials so that the active ingredients, such as vaccines, can act appropriately in living tissues after a predetermined time interval from the initial inoculation . As a technology structurally related to the present invention, a technique in which the needle portion (named "bullet") of a microneedle attached to