NANOTECHNOLOGY PATENTS IN DRUGS AND DIAGNOSIS
Nanocrystals Patents in Drug Delivery
Nanocrystalline solid dispersion compositions possessing discrete particles have been patented. The discrete particles consist of pharmaceutically and nutraceutically active veterinary crystals. These particles have been dispersed in the crystallization inducer and/or are coexisting with crystals of the crystallization inducer matrix. A pharmaceutically acceptable excipient is added (as and when required) to this matrix as an optional material. This invention generates nanocrystalline solid dispersions in a novel one-step process. It is useful to improve the dissolution of pharmaceutically and nutraceutically active veterinary material as well as to improve the bioavailability. The decreased crystallite size leads to dissolution enhancement [68].
Pyropheophorbides such as 2-devinyl-2-(l-hexyloxyethyl)pyropheophorbide (HPPH) is a hydro- phobic photosensitizing anticancer drug and it is used for photodynamic therapy. Paras Prasad et al. have patented their invention of nanocrystals (contain the drug pyropheophorbides) useful for photodynamic therapy. This patent is related to the nanocrystals or polymer doped nanocrystals of hydrophobic drug molecules. These nanocrystals have been dispersed in an aqueous system without any stabilizer or surfactant. For example, pharmaceutical preparation consisting of nanocrystals or polymer-doped nanocrystals of HPPH. Drug efficacy of this pharmaceutical preparation is found to be the same with a drug formulated in a conventional drug delivery method in both in vitro and in vivo conditions [69].
Iron Oxide Nanaoparticle Patents in Drug Delivery
Inventors Jonathan Leor et al. have patented iron oxide NPs. In accordance with that patent, iron oxide NPs can be utilized in the treatment of non-infectious inflammatory disorders. They also disclose a treatment method for those disorders utilizing iron oxide NPs, pharmaceutical compositions, and other kits made with such particles [70].
Milk protein casein-coated iron oxide NPs have been patented recently for drug delivery applications. Drug-loaded iron oxide NPs are coated with an inner polymeric layer and an outer casein layer, with a layer-by-layer deposition method. Oral administration is possible with casein coating. The casein layer is degraded by intestinal protease, leading to a controlled or slow release of the drug [71].
Graphene Quantum Dots Patents
This patent explains the simple preparation of biocompatible polyethyleneglycol-graphene quantum dots (P-GQDs) using minimally hazardous chemicals. P-GQDs material is electrochemically synthesized (at room temperature) and embedded inside the polyethyleneglycol (PEG) matrix. In this method, a PEG coating over GQDs is avoided; instead GQDs are embedded inside a PEG matrix.
This patent has mainly focused on the two aspects of GQDs, i.e. size and ROS. Small size damages cell organelles; ROS hamper the cells and activities of cells in many ways. On the other side, GQDs material is used for bioimaging and drug delivery in HeLa cells. Hence, it is essential to maintain the fluorescence properties of the GQDs. Intracellular ROS assay suggests that ROS are involved in cytotoxicity activities. After considering these factors, the embedding of GQDs inside the PEG matrix is done to prepare the P-GQDs. The prepared P-GQDs reduce the cytotoxicity by controlling ROS production without affecting the fluorescence properties. A high concentration of P-GQDs (5.5 mg/mL) shows 60% cell viability and reduces ROS production [72].
GQDs Patents in Imaging
Graphene quantum dots are also used as fluorophores in imaging applications. Other semiconductor quantum dots have high brightness and photo-stability. However, they are toxic, and their large molecules contain heavy metal ions. Hence, biomolecules conjugated graphene quantum dots are now emerging as fluorophores for imaging applications. They have advantages such as good photo- luminescent properties, chemical inertness, and low cost [73].
ISSUES IN THE NANODRUG PATENTS
Monitoring of Nanodrugs
Nanotechnology develops innovative therapies and high-quality products at low cost. The medical and pharmaceutical fields should support these developments by adopting them. Pharmaceutical companies should make such innovative products available to the public instead of looking for shareholder profits. The U.S.-based FDA and USPTO are facing challenges to grant approval for new drugs and medical-related products designed with the principles of nanotechnology. Recently, the Indian government has formulated regulations (Guidelines for Evaluation of Nanopharmaceuticals in India) to monitor nanopharmaceuticals.
The FDA of CDER is monitoring drug products with nanomaterials. The impact of nanomaterials on safety and efficacy is assessed to form the regulations. To ensure safety when using nanomaterials, the characterizations of these nanomaterials should be conducted properly and in a scientifically reliable manner. The characterization techniques have some limitations, which can be identified with the help of the existing regulations [74, 75]. Necessary solutions can also be devised for such limitations in accordance w'ith the regulations. The characterization techniques are discussed in the subsequent sections.
Fornaguera and Maria have reported that nanomedicine is a revolution at the nanoscale. They have explained about the world market status of the nanomedicine (in 2017) by comparing nanomedicine availability with corresponding nanomedicine literature. They have also studied the involvement of the stakeholders and the most common challenges in the commercialization of nanomedicines. Figure 13.15 (a) exhibits a comparison study between nanomedicines and literature. Figure 13.15 (b) exhibits the stakeholders’ involvement and the challenges in the lab-to-market translation of nanomedicines [76].
As per the guidelines of the Indian government, nanopharmaceutical means a pharmaceutical preparation that contains nanomaterials intended for internal or external application on the body for the purpose of therapeutics, diagnostics, and any health benefit. A nanopharmaceutical should contain particles in the 1 to 1000 nm size range. Less than 1% of the particles with a size above 1000 nm cross the exemption limit. However, during the stable period, less than 10% variation in the particle size range is permitted, i.e. the nanopharmaceutical should not have varied or altered particle size range more than 10% due to instability. These guidelines apply to the finished nanopharmaceutical formulation and active pharmaceutical ingredient of a new' molecule or an already approved molecule w'ith altered dimensions, properties, or phenomenon (due to the application of
FIGURE 13.15 Schematic diagram related to nanomedicine, (a) Plot of nanomedicine situations in 2017 - nanomedicine available on the world market vs percentages corresponding to nanomedicine literature, (b) Stakeholders’ involvement in moving nanomedicines from lab to market and the most common challenges faced by them in this translation. (From Fornaguera, Cristina et al. 2017.)
nanotechnology) intended to apply in the diagnosis, treatment, mitigation, or prevention of diseases in humans [4].
