scholarly journals Development and In vitro Evaluation of Oral Controlled Release Formulations of Celecoxib Using Optimization Techniques

2006 ◽  
Vol 126 (7) ◽  
pp. 505-514 ◽  
Author(s):  
Sajeev CHANDRAN ◽  
Punnarao RAVI ◽  
Ranendra N. SAHA
Keyword(s):  
Controlled Release ◽  
Optimization Techniques ◽  
Controlled Release Formulations

Controlled-release components of PZP contraceptive vaccine extend duration of infertility

2008 ◽  
Vol 35 (6) ◽  
pp. 555 ◽  
Author(s):  
John W. Turner ◽  
Allen T. Rutberg ◽  
Ricky E. Naugle ◽  
Manpreet A. Kaur ◽  
Douglas R. Flanagan ◽  
...  
Keyword(s):  
Controlled Release ◽  
Cost Effective ◽  
Field Studies ◽  
In Vitro Testing ◽  
Fertility Reduction ◽  
Contraceptive Vaccine ◽  
Fertility Data ◽  
Controlled Release Formulations

Successful immunocontraception of wildlife relying on repeated access to individuals for boosters has highlighted the need to incorporate primer and booster immunisations into one injection. We have investigated use of controlled-release polymers (lactide–glycolide) in small pellets to provide delayed in vivo delivery of booster porcine zona pellucida (PZP) antigen and adjuvant. This report reviews pellet-making methodology, in vitro testing of controlled-release pellets and in vivo effects of controlled-release PZP vaccine. We assessed 3 different manufacturing approaches for producing reliable, cost-effective pellets: (1) polymer melting and extrusion; (2) solvent evaporation from polymer solution; and (3) punch and die polymer moulding. In vitro testing of release patterns of controlled-release formulations, towards development of a 3-year duration vaccine, provided estimates for in vivo use of pellet preparations. These in vitro studies demonstrated protein release delay up to 22 months using 100% l-lactide or polycaprolactone polymers. For in vivo tests, pellets (1-, 3-, and 12-month release delay) serving as boosters were administered intramuscularly with PZP/adjuvant liquid primer to wild horses (Equus caballus), white-tailed deer (Odocoileus virginanus) and African elephants (Loxodonta africana). Horse field studies assessed fertility via offspring counts and/or faecal-hormone pregnancy testing. Treatment decreased fertility 5.3–9.3-fold in Year 1 and 3.6-fold in Year 2. In preliminary testing in deer, offspring counts revealed treatment-associated fertility reduction of 7.1-fold Year 1 and 3.3-fold Year 2. In elephants, treatment elevated anti-PZP titres 4.5–6.9-fold from pretreatment (no fertility data).

Development of Nitrendipine Controlled Release Formulations Based on SLN and NLC for Topical Delivery: In Vitro and Ex Vivo Characterization

2008 ◽  
Vol 34 (7) ◽  
pp. 719-725 ◽  
Author(s):  
Kesavan Bhaskar ◽  
Chinnala Krishna Mohan ◽  
Meka Lingam ◽  
Veerareddy Prabhakar Reddy ◽  
Vobalaboina Venkateswarlu ◽  
...  
Keyword(s):  
Controlled Release ◽  
Ex Vivo ◽  
Topical Delivery ◽  
Controlled Release Formulations

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

Development and Evaluation of Controlled Release Mucoadhesive Tablets of Captopril

1970 ◽  
Vol 9 (3) ◽  
pp. 3318-3329
Author(s):  
Kranthi Kumar Kotta ◽  
L. Srinivas
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Xanthan Gum ◽  
Diffusion Mechanism ◽  
Matrix Tablets ◽  
Fickian Diffusion ◽  
Content Uniformity ◽  
In Vitro Drug Release ◽  
Mucoadhesive Tablets

The present investigation focuses on the development of mucoadhesive tablets of captopril which are designed to prolong the gastric residence time after oral administration. Matrix tablets of captopril were formulated using four mucoadhesive polymers namely guar gum, xanthan gum, HPMC K4M and HPMC K15M and studied for parameters such as weight variation, thickness, hardness, content uniformity, swelling index, mucoadhesive force and in vitro drug release. Tablets formulated Xanthan gum or HPMC K4M with HPMC K15M provide slow release of captopril over period of 12 hr and were found suitable for maintenance portion of oral controlled release tablets. The cumulative % of drug release of formulation F9 and F10 were 90 and 92, respectively. In vitro release from these tablets was diffusion controlled and followed zero order kinetics. The ‘n’ values obtained from the pappas-karsemeyer equation suggested that all the formulation showed drug release by non-fickian diffusion mechanism. Tablets formulated Xanthan gum or HPMC K4M with HPMC K15M (1:1) were established to be the optimum formulation with optimum bioadhesive force, swelling index & desired invitro drug release. This product was further subjected to stability study, the results of which indicated no significant change with respect to Adhesive strength and in vitro drug release study.

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