Effect of solvents on physical properties and release characteristics of monolithic hydroxypropylmethylcellulose matrix granules and tablets

Release kinetics of hydroxypropyl methylcellulose governing drug release and hydrodynamic changes of matrix tablet

BACKGROUND

Hydrophilic hydroxypropyl methylcellulose (HPMC) matrix tablets are the standard role model of the oral controlled-release formulation. Nevertheless, the HPMC kinetics for the mechanistic understanding of drug release and hydrodynamic behaviors are rarely investigated. This study aims to investigate the release behaviors of both HPMC and paracetamol (model drug) from the hydrophilic matrix tablet.

METHODS

Two different viscosity grades of HPMC were used (Low viscosity: 6 cps, High viscosity: 4,000 cps). Three different ratios of drug/HPMC (H:38.08%, M:22.85%, and L:15.23% (w/w) of HPMC amounts in total weight) matrix tablets were prepared by wet granulation technique. The release profiles of the drug and HPMC in a matrix tablet were quantitatively analyzed by HPLC and 1H-nuclear magnetic resonance (NMR) spectroscopy. The hydrodynamic changes of HPMC were determined by the gravimetric behaviors such as swelling and erosion rates, gel layer thickness, front movement data,and distributive near-infrared (NIR) chemical imaging of HPMC in a matrix tablet during the dissolution process.

RESULTS

High viscosity HPMC tablets showed slower release of HPMC than the release rate of drug, suggesting that drug release preceded polymer release.Different hydration phenomenon was qualitatively identified and corresponded to the release profiles. The release behaviors of HPMC and drug in the tablet could be distinguished with the significant difference with fitted dissolution kinetics model (Low viscosity HPMC 6cps; Korsmeyer-Peppas model, High viscosity HPMC 4000cps; Hopfenberg model, Paracetamol; Weibull model) according to the weight of ingredients and types of HPMC.

CONCLUSION

The determination of HPMC polymer release correlating with drug release, hydrodynamic behavior, and NIR chemical imaging of HPMC can provide new insights into the drug release-modulating mechanism in the hydrophilic matrix system.

Production of first- and second-generation ethanol for use in alcohol-based hand sanitizers and disinfectants in India

Emergence of "severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)" causing "COVID-19" or "coronavirus disease 19" as pandemic has got worldwide attention towards hygiene as the first line of defense for the infection control. It is first line of defense not only from COVID-19 but also from other infectious diseases caused by deadly pathogens such as cholera, hepatitis, tuberculosis, polio, etc. Absence of any particular vaccine or treatment let World Health Organization (WHO) recommend to the public to maintain social distancing along with regularly washing their hands with soap, sanitize their hands (where washing is not possible), and disinfect their belongings and buildings to avoid the infection. Out of various formulations available in the market, WHO has recommended alcohol-based hand sanitizers, which mainly comprise of ethanol, isopropyl alcohols, and hydrogen peroxides in different combinations due to their high potential to kill the broad range of pathogens including bacterial, viral, fungal, helminthes, etc. Therefore, alcohol-based sanitizers are in high demand since centuries to prevent infection from pathogenic diseases. Ethanol is the most common and popular alcohol in terms of vanishing wide range of pathogens, convenient to use and its production. Ethanol is produced worldwide and is used in various sectors, e.g., beauty and cosmetics, food and beverages, and as the most demanding gasoline additive. The present review is focused on the ethanol production in India, its diversified applications emphasizing hand sanitizers with discussions on formulation of sanitizer and disinfectants, and viability of lignocellulosic and food grain-based ethanol. The review article also emphasizes on the technological details of 1G and 2G ethanol production, their associated challenges, and inputs for the improved ethanol yields so as to strengthen the supply chain of ethanol in India, and making "Atmanirbhar Bharat" (Self-reliant India) campaign of Indian government successfully viable.

Development of Dermal Films Containing Miconazole Nitrate

This study aims to develop new antifungal dermal films based on their mechanical properties (elongation, adhesion, behaviour towards vapour moisture) and the in vitro availability of miconazole nitrate, used as a pharmaceutical active ingredient in various concentrations. The three polymeric films prepared were translucent or shiny, with the surface of 63.585 cm², 0.20⁻0.30 mm thickness, and content of miconazole nitrate of 3.931 or 15.726 mg·cm². The mechanical resistance and elongation tests demonstrated that the two films based on hydroxyethyl cellulose (HEC) polymer were more elastic than the one prepared with hydroxypropyl methylcellulose (HPMC). The vapour water absorption and vapour water loss capacity of the films revealed that the HPMC film did not dry very well in the process of preparation by the evaporation of the solvent technique, unlike the HEC films that jellified more evenly in water and had higher drying capacity at 40 °C. The in vitro availability of miconazole nitrate from dermal films was evaluated using the Franz diffusion cell method, through a synthetic membrane (Ø 25 mm × 0.45 µm) and acceptor media with pH 7.4 (phosphate buffer and sodium lauryl sulphate 0.045%), resulting a release rate of up to 70%.

New insights on solvent implications in flow behavior and interfacial interactions of hydroxypropylmethyl cellulose with cells/bacteria

The properties of polymers in solutions are affected by the solvent characteristics used in the processing stage. This work contributes to understanding the conformation changes under shear rheology of hydroxypropylmethyl cellulose (HPMC) in different solvents. Flow behavior in a large shear rate domain provides information on establishing the proper conditions in which the polymer solutions can be processed into uniform films. It was found that HPMC/solvent interactions influence the final architecture of macromolecules in the solid phase and implicitly the organization of polar/non-polar groups at the surface. This led to variable wettability and consequently to adhesion or cohesion of HPMC with biological agents. These new findings are important in tuning surface properties as demanded in bioengineering or regenerative medicine, where it is essential to establish adequate spreading conditions at the HPMC interface with cells or bacteria.

Surelease as granulating liquid in preparation of sustained release matrices of ethylcellulose and theophylline

OBJECTIVES

Use of Surelease as a granulation liquid in preparation of granules and matrices of theophylline and ethylcellulose was evaluated.

MATERIALS AND METHODS

Physical mixtures (at 1:1 or 1:1.5 drug:polymer) were granulated using water, Surelease or diluted Surelease as granulating liquid. The granule characteristics (shape, size, flow rate, mechanical properties, friability and release profile) were studied. Afterwards, matrices were manufactured and their crushing strengths, friability and release profiles were determined.

RESULTS

Granulation produced agglomerated particles with better flowability than physical mixtures. Change of granulation liquid from water to Surelease or diluted Surelease led to the marginal increase in size of granules at 1:1 drug:polymer, however, the flow rate and Carr's index were considerably improved. The hardness, elastic modulus, friability and rate of drug release were not affected by granulation liquid. Increase in polymer content resulted in reduction in size of granules, flow rate, elastic modulus and rate of drug release. However hardness of the granules was unaffected. Granulation process and granulation liquid did not affect the hardness, and dissolution rate of matrices at 1:1 drug:polymer, while the use of Surelease or diluted Surelease as a granulating liquid, increased the hardness and decreased drug release rate at 1:1.5 drug:polymer. Matrices prepared from Surelease or diluted Surelease showed similar characteristics.

CONCLUSIONS

Surelease is a suitable granulating liquid for preparation of ethylcellulose matrices especially when high amount of polymer is used and could not only improve the flow and compatibility of the granules, but also help in reducing the rate of drug release.