This article summarizes a novel concept comprising of drug loaded empty capsule shells, by Dr. Hemant Joshi. The patents titled ‘Physically/molecularly distributed and/or chemically bound medicaments in empty, hard capsule shells’ summarize the same capsule dosage form, which contains medicaments in the core matrix and in the shell.
Inspired by combination drug therapy, Dr. Hemant Joshi came up with a novel capsule, which I am calling here as “Joshi capsule” henceforth in this article. As described in patent # 8728521, the “Joshi capsule” was designed to incorporate medicaments or drugs in the capsule shells (body and cap). The key advantage of the patent is to produce a drugdrug combination drug delivery system in which the two drugs can be physically separate and will not interact with each other. The other advantage of incorporation of drug in the shell was to obtain a desired rate of release of the medicament from the shell, predominantly for potent drugs. The drug can be physically incorporated in the shell or could be chemically bound to the polymer used to make the capsule shell. A typical capsule shell contains a body and cap. Thus one can incorporate drug A in the capsule cap and drug B in capsule body. This way one can get both drugs A and B in the capsule shell matrix and another drug C inside the capsule core. The type of medicaments could be from any class preferably low-dose medicaments.
Figure 1. A drawing of Joshi Capsule which can have 2-4 different drugs in various combinations.A soluble drug is dissolved in the capsule shell forming composition. If insoluble, it could be physically dispersed or suspended. The drug can also be chemically bound to the polymer used in the capsule-shell composition. The capsules can be prepared by pin dip-coating (The dipping pins were heated at 55-95°C and the polymer solution was maintained at 1 to 10°C below its gelling temperature) or heat-melting methods. The polymers that can be used in making the empty, hard capsule shells can be divided into the following groups: Cellulose- or cellulose compounds, 2) Starch-based compounds, 3) Carrageenan 4) Acrylate compounds 5) Polyolefins and 6) Pullulan (a polysaccharide polymer consisting of maltotriose units).
A few examples of the utilization of “Joshi capsules” are as follows.
Entecavir (low dose) and Tenofovir (high dose) are antivirals drug used in treatment of Hepatitis B. Using the Joshi capsule, Entecavir (0.5 mg) can be put in the capsule shell and Tenofovir (300 mg) in the Core for the Chronic Hepatitis B Treatment
There are situations when there are frequent instances of increased blood pressure when a woman goes in labor. Clonidine (75 microgram), which reduces the blood pressure can be incorporated in the Capsule Shell and Bupivacaine (10 mg) which is an anesthetic can be incorporated in the Core. “Joshi capsule” can be used as a combination drug therapy for labor pain. There are many drugs which cause birth defects such as thalidomide and tretinoin. If contraceptive are incorporated in the capsule shell matrix, women taking such defect causing medicines will not get pregnant. There could be numerous uses like this for the Joshi capsules.