scholarly journals Eudraginated polymer blends: A potential oral controlled drug delivery system for theophylline

2012 ◽  
Vol 62 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Martins Emeje ◽  
Lucy John-Africa ◽  
Yetunde Isimi ◽  
Olobayo Kunle ◽  
Sabinus Ofoefule

Eudraginated polymer blends: A potential oral controlled drug delivery system for theophylline Sustained release (SR) dosage forms enable prolonged and continuous deposition of the drug in the gastrointestinal (GI) tract and improve the bioavailability of medications characterized by a narrow absorption window. In this study, a new strategy is proposed for the development of SR dosage forms for theophylline (TPH). Design of the delivery system was based on a sustained release formulation, with a modified coating technique and swelling features aimed to extend the release time of the drug. Different polymers, such as Carbopol 71G (CP), sodium carboxymethylcellulose (SCMC), ethylcellulose (EC) and their combinations were tried. Prepared matrix tablets were coated with a 5 % (m/m) dispersion of Eudragit (EUD) in order to get the desired sustained release profile over a period of 24 h. Various formulations were evaluated for micromeritic properties, drug concentration and in vitro drug release. It was found that the in vitro drug release rate decreased with increasing the amount of polymer. Coating with EUD resulted in a significant lag phase in the first two hours of dissolution in the acidic pH of simulated gastric fluid (SGF) due to decreased water uptake, and hence decreased driving force for drug release. Release became faster in the alkaline pH of simulated intestinal fluid (SIF) owing to increased solubility of both the coating and matrixing agents. The optimized formulation was subjected to in vivo studies in rabbits and the pharmacokinetic parameters of developed formulations were compared with the commercial (Asmanyl®) formulation. Asmanyl® tablets showed faster absorption (tmax 4.0 h) compared to the TPH formulation showing a tmax value of 8.0 h. The Cmax and AUC values of TPH formulation were significantly (p < 0.05) higher than those for Asmanyl®, revealing relative bioavailability of about 136.93 %. Our study demonstrated the potential usefulness of eudraginated polymers for the oral delivery of the sparingly soluble drug theophylline.

Author(s):  
Anupam K Sachan ◽  
Saurabh Singh ◽  
Kiran Kumari ◽  
Pratibha Devi

Microspheres carrier system made from natural or synthetic polymers used in sustained release drug delivery system. The present study involves formulation and evaluation of floating microspheres of Curcumin for improving the drug bioavailability by prolongation gastric residence time. Curcumin, natural hypoglycemic agent is a lipophilic drug, absorbed poorly from the stomach, quickly eliminated and having short half-life so suitable to formulate floating drug delivery system for sustained release. Floating microspheres of curcumin were formulated by solvent evaporation technique using ethanol and dichloromethane (1:1) as organic solvent and incorporating various synthetic polymers as coating polymer, sustain release polymers and floating agent. The final formulation were evaluated various parameters such as compatibility studies, micrometric properties, In-vitro drug release and % buoyancy. FTIR studies showed that there were no interaction between drug and excipients. The surface morphology studies by SEM confirmed their spherical and smooth surface. The mean particles size were found to be 416-618µm, practical yield of microspheres was in the range of 60.21±0.052% - 80.87±0.043%, drug entrapment efficiency 47.4±0.065% - 77.9±0.036% and % buoyancy 62,24±0.161% - 88.63±0.413%. Result show that entraptmency increased as polymer (Eudragit RS100) conc. Increased. The drug release after 12 hrs. was 72.13% - 87.13% and it decrease as a polymer (HPMC, EC) concentration was decrease.


RSC Advances ◽  
2015 ◽  
Vol 5 (10) ◽  
pp. 7559-7566 ◽  
Author(s):  
Wulian Chen ◽  
Luqman Ali Shah ◽  
Li Yuan ◽  
Mohammad Siddiq ◽  
Jianhua Hu ◽  
...  

Controlled drug delivery system based on hydrophilic diblock copolymer covalently linked paclitaxel (PTX) via a disulfide linker.


Author(s):  
Ririyen Dessy N Siahaan ◽  
Hakim Bangun ◽  
Sumaiyah Sumaiyah

Objective: The objective of this study was to evaluate in vitro and in vivo of gastroretentive drug delivery system of cimetidine using hard alginate capsules.Methods: Drug release study was tested to various hard alginate capsules containing 200 mg cimetidine with paddle method dissolution apparatus in artificial gastric fluid pH 1.2. Concentrations of cimetidine were measured using ultraviolet spectrophotometer at 218.4 nm wavelength. The product that fulfilled the sustained release profile was evaluated for bioavailability using male rabbits at dose 9.3 mg/kg orally, and the antiulcer studies were evaluated by HCl-induced ulcer method at cimetidine dose 18 mg/kg once a day orally. Gastric lesions were evaluated by macroscopic and microscopic observations.Results: The results of drug release test showed that hard alginate capsule made from sodium alginate 500–600 cP gave sustained release profile of cimetidine for 12 h. In vivo bioavailability studies showed that cimetidine given with hard alginate capsules gave higher of Cmax, Tmax, and area under the curve of cimetidine compared to cimetidine that given with conventional hard gelatin capsules. The antiulcer studies showed that the healing effect of cimetidine that given with hard alginate capsules was faster than cimetidine given in suspension form. Cimetidine that given with hard alginate capsules macroscopically showed no gastric lesion and histopathologically also showed normal gastric mucosa of rats after 4 days treatment. However, cimetidine given in suspension form showed of 0.036±0.024 ulcer index and microscopically there was still erosion of gastric mucosa of rats after 4 days treatment.Conclusion: Floating gastroretentive of cimetidine using hard alginate capsules give a sustained release of cimetidine with better bioavailability and antiulcer effect of cimetidine.


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