Cerium-based nanoparticles (CeNPs), particularly cerium oxide (CeO₂), have been studied extensively for their antioxidant and prooxidant properties. However, their complete redox and enzyme-mimetic mechanisms of therapeutic action at the molecular level remain elusive, constraining their potential for clinical translation. Although the therapeutic effects of both antioxidant and prooxidant mechanisms generally are attributed to Ce³⁺ ↔ Ce⁴⁺ redox switching mediation, some studies have hinted at the involvement of unknown pathways in therapeutic effects. While redox switching is recognised increasingly as playing a key role in ROS-dependent cancer therapy, ROS-independent cytotoxicity mechanisms, such as Ce⁴⁺ dissolution and autophagy, also are emerging as being of importance. Although ROS-mediated prooxidant therapies are the most intensively studied, particularly in the context of cancer, the antioxidant activity deriving from the redox switching, particularly during radiation therapy, also plays an important role in the protection of normal cells during radiation therapy, hence reducing adverse effects. Since cancer cell proliferation results in aberrant behaviour of the tumour microenvironment (TME), then CeNP-based therapies are being used to address a multiplicity of known and unknown factors that aim to normalise the TME and thus prevent this aberrant behaviour. Although it is perceived that the pH plays a key role in the therapeutic performance of cerium-based nanoparticles, this is not conclusive because the relative importances of other factors, particularly Ce dissolution, Ce³⁺/Ce⁴⁺ ratio, cellular H₂O₂ level, and the role of anions, remain poorly understood. Consequently, the present work explores these multiple chemistry-driven mechanisms, which are both ROS-dependent and ROS-independent, in cancer therapy.

The study was designed to investigate the in vitro dissolution profile and compression characteristics of colon targeted matrix tablets prepared with HPMC E15 LV in combination with pectin and Chitosan. The matrix tablets were subjected to two dissolution models in various simulated fluids such as pH 1.2, 6, 6.8, 7.2, 5.5. The fluctuations in colonic pH conditions during IBD (inflammatory bowel disease) and the nature of less fluid content in the colon may limit the expected drug release in the polysaccharide-based matrices when used alone. The Hydrophilic hydroxyl propyl methylcellulose ether premium polymer (HPMC E15 LV) of low viscosity grade was used in the formulation design, which made an excellent modification in physical and compression characteristics of the granules. The release studies indicated that the prepared matrices could control the drug release until the dosage form reaches the colon and the addition HPMC E15 LV showed the desirable changes in the dissolution profile by its hydrophilic nature since the colon is known for its less fluid content. The hydrophilic HPMC E15 LV allowed the colonic fluids to enter into the matrix and confirmed the drug release at the target site from a poorly water soluble polymer such as Chitosan and also from water soluble Pectin. The dramatic changes occurred in the drug release profile and physicochemical characteristics of the Pectin, Chitosan matrix tablets when a premium polymer HPMC E15 LV added in the formulation design in the optimized concentration. Various drug release mechanisms used for the examination of drug release characteristics. Drug release followed the combined mechanism of diffusion, erosion, swelling and polymer entanglement. In recent decade, IBD attracts many patents in novel treatment methods by using novel drug delivery systems.

The term "reactive oxygen species" (ROS) refers to a family of extremely reactive molecules. They are crucial as secondary messengers in both physiological functioning and the development of cancer. Tumors have developed the ability to survive at elevated ROS levels with significantly higher H2O2 levels than normal tissues. Chemodynamic therapy is a novel approach to cancer treatment that generates highly toxic hydroxyl radicals via a Fenton/Fenton-like reaction between metals and peroxides. Inorganic nanoparticles cause cytotoxicity by releasing ROS. Inorganic nanoparticles can alter redox homoeostasis by generating ROS or diminishing scavenging mechanisms. Internalized nanoparticles generate ROS in biological systems independent of the route of internalisation. This method of producing ROS could be employed to kill cancer cells as a therapeutic strategy. ROS also play a role in regulating the development of normal stem cells, as excessive ROS disturb the stem cells' regular biological cycles. ROS treatment has a significant effect on normal cellular function. Mitochondrial ROS are at the centre of metabolic changes and control a variety of other cellular processes, which can lead to medication resistance in cancer patients. As a result, utilising ROS in therapeutic applications can be a double-edged sword that requires better understanding.

Background: Although, a number of formulations have been developed for the treatment of IBD yet the developed formulations are having side effects such as high dose, lack of solubility and permeability problems at the site of action. Very few formulations have been developed for the IBD treatment in the form of nanoparticles. Nanoparticles have shown their potential in the recent findings in the treatment of IBD at cellular level. This research work aims to develop nanosuspension of newly introduced drug Rifaximin currently available in the form of tablet for the treatment of IBD. Rifaximin in the form of tablet is given in high dose concentration so to avoid the large dose and to increase the permeability action of drug a nanosuspension is prepared using a well known polymer Eudragit S 100 which is itself a colon targeted polymer and simultaneously improve the site specific delivery of the drug. Method: We thoroughly reviewed and tested the previous work for the development of nanoparticles in the laboratory for the treatment of IBD. A number of research as well as review articles were followed in order to get quality information. For this all the research as well as review work was collected from the quality journals. A simple yet a high result oriented technique nanoprecipitation were used for the development of nanoparticles. Results: A total of 21 research and review papers were studied deeply. Before developing the final formula a number of trials were carried out and from the trials, the formulation which showed better release profile and presence of nanoparticles was then optimized and a total of five formulations were developed. In each of the five formulations the concentration of the polymer and external phase was varied along with the concentration change in P.F. 68 for getting a superior formulation in terms of release, size and entrapment. The least size nanosuspension was subjected to Transmission Electron Microscopy for confirmation of nanoparticles and to check the morphological characters of the prepared nanoparticles and size of the nanoparticles was in the range of 19nm to 25nm.The prepared formulation was subjected to stability studies and it was freeze dried. Conclusion: The outcome of this research work confirms the formation of nanoparticles and release profile of the prepared nanosuspension proved its site specificity. The release graphs indicated the release of the drug in colon proving its potential in the treatment of IBD and entrapment study indicates the drug entrapment capacity for delivering the required concentration of drug at the site of action. Moreover the nanoformulation reduces the dose and the side effects due to its specific targeting at the site of inflammation makes it a better choice over the tablets.

Background: Rifaximin is a non-systemic antibiotic used in the treatment of inflammatory bowel disease (IBD). Antibiotics are demonstrating a significant role in the treatment of IBD by altering the dysbiotic colonic microbiota and decreases the immunogenic and inflammatory response in the patient population. Mucoadhesive colon targeted nanoparticles provide the site-specific delivery and extended stay in the colon. Since the bacteria occupy the lumen, spread over the surface of epithelial cells, and adhere to the mucosa, delivering the rifaximin as a nanoparticles with the mucoadhesive polymer enhances the therapeutic efficacy in IBD. The objective was to fabricate and characterize the rifaximin loaded tamarind gun nanoparticles and study the therapeutic efficacy in the TNBS-induced IBD model rats. Materials and methods: The experimentation includes fabrication and characterization of drug excipient compatibility by FTIR. The fabricated nanoparticles were characterized for the hydrodynamic size and zeta potential by photon correlation spectroscopy and also analyzed by TEM. Selected best formulation was subjected to the therapeutic efficacy study in TNBS-induced IBD rats, and the macroscopic, microscopic and biochemical parameters were reported. Results: The study demonstrated that the formulation TGN1 is best formulation in terms of nanoparticle characterization and hydrodynamic size which showed the hydrodynamic size of 171.4 nm and the zeta potential of –26.44 mV and other parameters such as TEM and drug release studies were also reported. The therapeutic efficacy study revealed that TGN1 is efficiently reduced the IBD inflammatory conditions as compared to the TNBS control group and reference drug mesalamine group. Background: Rifaximin is a non-systemic antibiotic used in the treatment of inflammatory bowel disease (IBD). Antibiotics are demonstrating a significant role in the treatment of IBD by altering the dysbiotic colonic microbiota and decreases the immunogenic and inflammatory response in the patient population. Mucoadhesive colon targeted nanoparticles provide the site-specific delivery and extended stay in the colon. Since the bacteria occupy the lumen, spread over the surface of epithelial cells, and adhere to the mucosa, delivering the rifaximin as a nanoparticles with the mucoadhesive polymer enhances the therapeutic efficacy in IBD. The objective was to fabricate and characterize the rifaximin loaded tamarind gun nanoparticles and study the therapeutic efficacy in the TNBS-induced IBD model rats. Materials and methods: The experimentation includes fabrication and characterization of drug excipient compatibility by FTIR. The fabricated nanoparticles were characterized for the hydrodynamic size and zeta potential by photon correlation spectroscopy and also analyzed by TEM. Selected best formulation was subjected to the therapeutic efficacy study in TNBS-induced IBD rats, and the macroscopic, microscopic and biochemical parameters were reported. Results: The study demonstrated that the formulation TGN1 is best formulation in terms of nanoparticle characterization and hydrodynamic size which showed the hydrodynamic size of 171.4 nm and the zeta potential of –26.44 mV and other parameters such as TEM and drug release studies were also reported. The therapeutic efficacy study revealed that TGN1 is efficiently reduced the IBD inflammatory conditions as compared to the TNBS control group and reference drug mesalamine group.