scholarly journals Application of Curdlan to Controlled Drug Delivery. III. Drug Release from Sustained Release Suppositories in Vitro.

1995 ◽  
Vol 18 (8) ◽  
pp. 1154-1158 ◽  
Author(s):  
Motoko KANKE ◽  
Emi TANABE ◽  
Hirokazu KATAYAMA ◽  
Yoko KODA ◽  
Hironori YOSHITOMI
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):  
Abdul Baquee Ahmed ◽  
Iman Bhaduri

Objective: The objective of the present study was to chemical modification, characterization and evaluation of mucoadhesive potentiality of Assam bora rice starch as potential excipients in the sustained release drug delivery system. Methods: The starch was isolated from Assam bora rice and esterified using thioglycolic acid and characterized by Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC) and Nuclear magnetic resonance (NMR). The 10% w/v gel formulation based on modified bora rice starch loaded with irinotecan (0.6%) was prepared and evaluated for various rheological properties, ex-vivo mucoadhesion using goat intestine and in vitro drug release study in phosphate buffer pH 6.8.Results: The chemical modification was confirmed by FT-IR and NMR studies with the presence of the peak at 2626.74 cm-1 and a singlet at 2.51 respectively due to–SH group. Ex-vivo mucoadhesion studies showed 6.6 fold increases in mucoadhesion of the modified starch with compared to native starch (46.3±6.79g for native starch; 308.7±95.31g for modified starch). In vitro study showed 89.12±0.84 % of drug release after 6 h in phosphate buffer pH 6.8 and the release kinetics followed Non-Fickian diffusion.Conclusion: The modified Assam bora rice starch enhanced a mucoadhesive property of the native starch and thus, can be explored in future as a potential excipient for the sustained release mucoadhesive drug delivery system.


2019 ◽  
Vol 225 ◽  
pp. 122-132 ◽  
Author(s):  
Hany El-Hamshary ◽  
Mohamed H. El-Newehy ◽  
Meera Moydeen Abdulhameed ◽  
Ayman El-Faham ◽  
Abeer S. Elsherbiny

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.


2017 ◽  
Vol 32 (5) ◽  
pp. 469-486 ◽  
Author(s):  
Gang Zhou ◽  
Jing Zhang ◽  
Jun Tai ◽  
Qianyi Han ◽  
Lei Wang ◽  
...  

The development of controlled drug delivery systems for bone regeneration, especially microspheres, has become a research hotspot in recent years. Chitosan and its derivative O-carboxymethyl chitosan have been considered to be an effective way for controlled drug delivery due to their nontoxicity and biodegradability. Currently, most of the studies have researched on synthesizing and characterizing chitosan and O-carboxymethyl chitosan. However, few studies have focused on the differences between chitosan microspheres and O-carboxymethyl chitosan microspheres directly. In this study, chitosan and O-carboxymethyl chitosan microspheres were developed by water-in-oil emulsification cross-linking method using vanillin as the cross-linking agent, and then their physicochemical properties were evaluated by Fourier transform infrared spectroscopy, scanning electron microscopy, and in vitro release testing. The results showed that O-carboxymethyl chitosan was successfully modified by adding carboxymethyl group at the chitosan C6 position.The particle size of chitosan microspheres (50–90 µm) was significantly larger than that of O-carboxymethyl chitosan microspheres (10–50 µm), and the drug release profile of O-carboxymethyl chitosan microspheres showed larger initial burst release within the first day and sustained release at the fourth day, while chitosan microspheres showed sustained release at the seventh day. In addition, Cell Counting Kit-8 assay showed that MC3T3-E1 proliferated well and highly expressed the alkaline phosphatase marker protein on both chitosan and O-carboxymethyl chitosan microspheres. Overall, both chitosan and O-carboxymethyl chitosan microspheres showed good biocompatibility, and chitosan microspheres were superior to O-carboxymethyl chitosan microspheres. Moreover, the different drug release rates suggest that chitosan and O-carboxymethyl chitosan microspheres have the potential to be used for the repair of different bone defects.


Author(s):  
Bhikshapathi D. V. R. N. ◽  
Chenna Madipalli Shalina ◽  
Vishnu Pulavarthy ◽  
Viswaja Medipally

The aim of this study was to explore the application of Gelucire 43/01 for the design of sustained release gastro retentive drug delivery system of Amlodipine besylate. Gelucire 43/01 has been used in floating sustained release formulations to prolong gastric residence time and increase its bioavailability. Gelucire 43/01 in combination with HPMC and Polyox was used as a release retarding polymer. HPMC of various viscosity grades HPMC K4M, HPMC K15M and HPMC K100M in combination of Gelucire were tested to obtain optimal total floating time as well as controlled drug release for prolonged period. Melt granulation technique has been used to prepare gastro retentive Amlodipine besylate formulations. All the formulations were evaluated in vitro for their floating ability and drug release. The floating times of all tablet formulations were greater than 12h. HPMC K4M in combination with Gelucire as polymeric matrix enhanced the drug release due to addition of hydrophilic polymer facilitated the swelling and erosion of the tablets. Incorporation of low viscosity polymer HPMC K100 M resulted in optimal floating as well as drug release for longer time. In vivo studies of optimized formulation show floating ability for 6 h in stomach. The results indicate that Gelucire 43/01 in combination with dissolution enhancers HPMC increase the permeability of the wax matrix, which provides improved dissolution thereby bioavailability of Amlodipine besylate and can be considered as a carrier for the development of sustained release floating drug delivery systems.  


Author(s):  
A. Bhavani ◽  
B. Hemalatha ◽  
K. Padmalatha

The present focus is on the development of sustained release formulations due to its inherent boons. There are several advantages of sustained release drug delivery over conventional dosage forms like improved patient compliance, reduction in fluctuation and increased safety margin of potent drug. The present study was aimed to prepare a sustained drug delivery system to design a controlled release oral dosage form of Cefpodoxime proxetil. The sustained release matrix tablets of Cefpodoxime proxetil were prepared by wet granulation and evaluated for different parameters such as weight variation, drug content, thickness, hardness, friability and In vitro release studies. The in vitro dissolution study was carried out for 12 hours using USP (Type- II) paddle apparatus in hydrochloride (0.1N) as dissolution media for first 2 hours and phosphate buffer (pH 6.8) for next 10 hours. Based on the in vitro dissolution data, formulation F8 was selected as the best formulation from Cefpodoxime proxetil formulations (F1 – F9) as the drug release was retarded up to 12 hours with 96.29 % and followed zero order release kinetics & drug release mechanism was diffusion.


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.


2006 ◽  
Vol 514-516 ◽  
pp. 1015-1019 ◽  
Author(s):  
Rangasamy Jayakumar ◽  
Rui L. Reis ◽  
João F. Mano

N-Carboxymethyl chitosan (NCMC) is a water soluble derivative of chitosan. The NCMC beads were prepared by using ionotropic gelation process with the counter polyanion tripolyphoshate at pH 4.0 and characterized by scanning electron microscopy. The swelling behavior of the beads at different time intervals was monitored at different pH conditions. The in vitro drug release behavior in various pH solutions was studied using indomethacin as a model drug with two different concentrations (0.3 and 0.6% w/w). The release percent of indomethacin from NCMC beads was found to increase with increasing of pH in phosphate buffer solution medium due to the ionization of carboxymethyl group and high solubility of indomethacin in alkaline medium. These results indicated that the NCMC beads are useful for controlled drug delivery systems through oral administration by avoiding the drug release in the highly acidic gastric fluid region of the stomach.


RSC Advances ◽  
2015 ◽  
Vol 5 (6) ◽  
pp. 4162-4170 ◽  
Author(s):  
Xinfeng Cheng ◽  
Yong Jin ◽  
Tongbing Sun ◽  
Rui Qi ◽  
Baozhu Fan ◽  
...  

A novel diselenide crosslinked poly(NIPAM-co-HEA) hydrogel was successfully synthesized, which exhibits a dual-stimuli-responsive drug release behaviors,i.e., thermo-induced slow sustained release and oxidation-induced quick burst release.


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