Synthesis of Breathing Metallopolymer Hollow Spheres for Redox-Controlled Release

Purpose. Study pore size effect and morphology of mesoporous silica on metoprolol tartrate release.Methodology. A sample of hollow mesoporous silicon dioxide with amino-functional groups containing 12.7 wt. % metoprolol tartrate has been investigated as potential carriers for the controlled release of active substance. Studies of the release profiles of metoprolol tartrate were performed under the following conditions: dissolution medium was buffer solution with a pH of 7.4 (phosphate buffer); sampling time: from 0.5 h before 18 h. The metoprolol concentration in the liquid phase was evaluated by a UV-Vis spectrophotometer (Persee TU-190, Beijing, China) by use of quartz cuvettes with an optical path length of 1 cm at a maximum wavelength of 274 nm.Findings. In this work we have studied mesoporous silica as possible carrier to controlled release of metoprolol tartrate, a drug used in the treatment of some diseases of the cardiovascular system. The material for research was a sample of hollow mesoporous silicon dioxide with amino-functional groups 200–400 nm in size and 20–30 nm in shell thickness. A calibrated curve to determine the amount of metoprolol was constructed by determining the absorption dependence of the concentration of metoprolol in the range from 10 to 300 ppm. The same drug concentration was obtained as calculated from the drug release test formula, which concludes that the release of metoprolol is controlled.Originality. The controlled release of a sample of hollow spheres of mesoporous silicon dioxide filled with metoprolol tartrate was studied, which was synthesized by the School of Chemistry and Chemical Engineering, Qilu University of Technology, using a new technology, where hollow spheres of mesoporous silicon dioxide with amino groups were synthesized using CO2 gas bubbles as templates.Practical value. The metoprolol release amount could achieve a 50% release amounts within 1 hour and 90% within 5 hours, indicating that the synthesized mesoporous hollow sphere could achieve controlled drug release, and shows the potential of carriers with stimulus response and targeted therapy.

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Controlled release antibiotics for dry powder lung delivery

Drug Development and Industrial Pharmacy ◽

10.1080/03639040903099769 ◽

2009 ◽

Vol 00 (00) ◽

pp. 090805050810080-8 ◽

Cited By ~ 1

Author(s):

Handoko Adi ◽

Paul Michael Young ◽

Hak-Kim Chan ◽

Rania Salama ◽

Daniela Traini

Keyword(s):

Controlled Release ◽

Dry Powder ◽

Lung Delivery

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Controlled Release Polymeric Formulations

10.1021/bk-1976-0033 ◽

1976 ◽

Cited By ~ 34

Keyword(s):

Controlled Release

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A New Controlled Release System for Standard 0.052â³ and 0.038â³ Gianturco Coils

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(97)84371-9 ◽

1998 ◽

Vol 31 (2) ◽

pp. 153A ◽

Cited By ~ 1

Author(s):

C Owada

Keyword(s):

Controlled Release ◽

Release System ◽

Controlled Release System ◽

Gianturco Coils

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Controlled Release of Metformin Hydrochloride I. In vitro Release from Physical Mixture Containing Xanthan Gum as Hydrophilic Rate Retarding Polymer

Dhaka University Journal of Pharmaceutical Sciences ◽

10.3329/dujps.v4i1.200 ◽

1970 ◽

Vol 4 (1) ◽

Author(s):

Mashkura Ashrafi ◽

Jakir Ahmed Chowdhury ◽

Md Selim Reza

Keyword(s):

Controlled Release ◽

Xanthan Gum ◽

In Vitro Release ◽

Correlation Coefficients ◽

High Ratio ◽

Water Soluble ◽

Metformin Hydrochloride ◽

Model Drug ◽

Very High

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size 1. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

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