Formulation and Evaluation of Metoprolol Controlled Release Formulations

Aim: The main perspective of the present research work was to prepare Metoprolol floating controlled release formulations. Methodology: After performing the characterization studies, Metoprolol tablets were prepared using various concentrations of poly ethylene oxide (PEO) WSR 303 (5% to 30%) by direct compression method. Formulations MP1 and MP6 were formulated using PEO WSR 303. Various pre and post compression parameters were evaluated. Dissolution studies were performed for the prepared tablets using dissolution medium of 0.1N hydrochloric acid. Results: Characterization studies like Fourier Transform Infra Red (FTIR) and Scanning Electron Microscopy (SEM) for Metoprolol, Polyethylene oxide WSR 303 and their combination were carried out, which revealed that there is no interaction between drug and polymer. The dissolution studies showed the controlled release pattern of Metoprolol up to 24h. The formulation MP5 prepared using 25% w/w of PEO WSR 303 showed maximum drug release of 98.22% at 24h. Similar drug release profile was observed for MP6 which was formulated using 30%w/w PEO WSR 303. These two formulations were further added with various concentrations of sodium bicarbonate (5% to 15%) and citric acid (2.5% to 10%) which enhanced floating of drug. Formulation MP8 containing 10% of sodium bicarbonate with 25% PEO WSR 303 showed less buoyancy lag time and prolonged drug release. Formulation MP15 showed very less buoyancy lag time of 4sec. Conclusion: Thus the prepared Metoprolol floating tablets showed prolonged drug release which could be a promising formulation for anti-hypertensive patients.

Preparation and Evaluation of Captopril Oral Floating Controlled Release Formulations

Aim: Dosing frequency is a major hurdle in geriatrics with frequent drug administration. In such cases, oral controlled release floating formulations are helpful which causes reduction in dosing frequency and fluctuation of drug levels in plasma. The main aim of the current research was to prepare Captopril floating controlled release formulations in order to achieve extended gastric retention in the upper GIT. Methodology: Captopril tablets were prepared using different concentrations of poly ethylene oxide water soluble resin (PEO WSR) 303 (5% to 30%) by direct compression technique. Captopril formulations CSP1 and CSP6 were formulated using PEO WSR 303. Pre and post compression parameters were evaluated. Dissolution studies were performed for the prepared tablets using 0.1N hydrochloric acid as dissolution medium. Results: The dissolution studies showed controlled drug release up to 12h. The formulation CSP5 prepared using 25% w/w of PEO WSR 303 showed maximum drug release of 97.97% at 12h. Almost similar drug release profile was also observed for CSP6 which was prepared using 30%w/w PEO WSR 303. These two formulations were further added with various concentrations of sodium bicarbonate (5% to 15%) and citric acid (2.5% to 10%) which enhanced floating of drug in Gastro intestinal tract (GIT). Formulation CSP8 containing 10% of sodium bicarbonate with 25% PEO WSR 303 showed less buoyancy lag time and prolonged drug release. Formulation CSP15 showed very less buoyancy lag time of 5sec. Characterization studies like Fourier Transform Infra Red spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were also carried out. Conclusion: The prepared Captopril floating tablets could be an alternative formulation for prolonged drug release.

Microencapsulation of Bacteriophages Using Membrane Emulsification in Different pH-Triggered Controlled Release Formulations for Oral Administration

An E.coli-specific phage was encapsulated in three different pH responsive polymer formulations using the process of membrane emulsification. Small 100 µm capsules were fabricated and shown to afford phages suitable acid protection upon exposure to pH 1.5. Selection of polymer formulations allowed controlled release of phages at pH 5.5, pH 6 and pH 7. Other aspects of phage encapsulation including factors affecting encapsulation yield, release kinetics, acid and storage stability were evaluated. The work presented here would be useful for future evaluation of new therapeutic strategies including microbiome editing approaches allowing pH-triggered release of phages and delivery of encapsulated cargo to different intestinal compartments. The size of the capsules were selected to permit ease of delivery using small bore oral gavage tubes typically used in pre-clinical studies for evaluation of drug substances using small animal vertebrate models such as in mice and rats.

Mosquito‐repellent controlled‐release formulations for fighting infectious diseases

Malaria is a principal cause of illness and death in countries where the disease is endemic. Personal protection against mosquitoes using repellents could be a useful method that can reduce and/or prevent transmission of mosquito-borne diseases. The available repellent products, such as creams, roll-ons, and sprays for personal protection against mosquitoes, lack adequate long-term efficacy. In most cases, they need to be re-applied or replaced frequently. The encapsulation and release of the repellents from several matrices has risen as an alternative process for the development of invention of repellent based systems. The present work reviews various studies about the development and use of repellent controlled-release formulations such as polymer microcapsules, polymer microporous formulations, polymer micelles, nanoemulsions, solid-lipid nanoparticles, liposomes and cyclodextrins as new tools for mosquito-borne malaria control in the outdoor environment. Furthermore, investigation on the mathematical modelling used for the release rate of repellents is discussed in depth by exploring the Higuchi, Korsmeyer-Peppas, Weibull models, as well as the recently developed Mapossa model. Therefore, the studies searched suggest that the final repellents based-product should not only be effective against mosquito vectors of malaria parasites, but also reduce the biting frequency of other mosquitoes transmitting diseases, such as dengue fever, chikungunya, yellow fever and Zika virus. In this way, they will contribute to the improvement in overall public health and social well-being.

Controlled Delivery Formulations

In the last few decades, controlled release formulations have gained an extraordinary interest [...]