Controlled release of pentoxifylline from polymeric matrices

1998 ◽  
Vol 32 (8) ◽  
pp. 440-442 ◽  
Author(s):  
O. N. Pozharitskaya ◽  
V. A. Vainshtein
Keyword(s):  
Controlled Release ◽  
Polymeric Matrices

scholarly journals Effect of various surfactants and their concentration on controlled release of captopril from polymeric matrices

2008 ◽  
Vol 58 (2) ◽  
pp. 151-162 ◽  
Author(s):  
Ali Nokhodchi ◽  
Davoud Hassan-Zadeh ◽  
Farnaz Monajjem-Zadeh ◽  
Nita Taghi-Zadeh
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Hydroxypropyl Methylcellulose ◽  
Water Soluble ◽  
Partial Replacement ◽  
Polymeric Matrices ◽  
Control Drug ◽  
Significant Difference ◽  
Release Data

Effect of various surfactants and their concentration on controlled release of captopril from polymeric matricesVarious methods are available to formulate water soluble drugs into sustained release dosage forms by retarding the dissolution rate. One of the methods used to control drug release and thereby prolong therapeutic activity is to use hydrophilic and lipophilic polymers. In this study, the effects of various polymers such as hydroxypropyl methylcellulose (HPMC), ethylcellulose (EC) and sodium carboxymethylcellulose (CMC) and surfactants (sodium lauryl sulphate, cetyltrimethylammonium bromide and Arlacel 60) on the release rate of captopril were investigated. The results showed that an increase in the amount of HPMC K15M resulted in reduction of the release rate of captopril from these matrices. When HPMC was partly replaced by NaCMC (the ratio of HPMC/NaCMC was 5:1), the release rate of the drug significantly decreased. However, there was no significant difference in release rate of captopril from matrices produced with ratios of 5:1 and 2:1 of HPMC/NaCMC. The presence of lactose in matrices containing HPMC and NaCMC increased the release rate of captopril. It was interesting to note that although partial replacement of HPMC by EC reduced the release rate of the drug (ratio of HPMC/EC 2:1), the release rate was increased when the ratio of HPMC/EC was reduced to 1:1. The effects of various surfactants on the release rate of captopril from HPMC/EC (1:1) matrices were also investigated. The results showed that the surfactants did not significantly change the release rate of the drug. Release data were examined kinetically and the ideal kinetic models were estimated for the drug release. The kinetic analysis of drug release data from various formulations showed that incorporation of surfactants in HPMC/EC matrices did not produce a zero-order release pattern.

Controlled Release of Bis(phosphonate) Pharmaceuticals from Cationic Biodegradable Polymeric Matrices

2011 ◽  
Vol 50 (9) ◽  
pp. 5873-5876 ◽  
Author(s):  
Konstantinos D. Demadis ◽  
Maria Paspalaki ◽  
Joanna Theodorou
Keyword(s):  
Controlled Release ◽  
Polymeric Matrices

Controlled release antibiotics for dry powder lung delivery

2009 ◽  
Vol 00 (00) ◽  
pp. 090805050810080-8 ◽  
Author(s):  
Handoko Adi ◽  
Paul Michael Young ◽  
Hak-Kim Chan ◽  
Rania Salama ◽  
Daniela Traini
Keyword(s):  
Controlled Release ◽  
Dry Powder ◽  
Lung Delivery

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

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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