Physico-chemical characterization of pH-sensitive N -Succinyl chitosan- g -poly (acrylamide- co -acrylic acid) hydrogels and in vitro drug release studies

2017 ◽  
Vol 139 ◽  
pp. 38-54 ◽  
Author(s):  
Shahid Bashir ◽  
Yin Yin Teo ◽  
S. Ramesh ◽  
K. Ramesh
2008 ◽  
Vol 322 (1) ◽  
pp. 333-341 ◽  
Author(s):  
Dayong Teng ◽  
Jingli Hou ◽  
Xinge Zhang ◽  
Xin Wang ◽  
Zhen Wang ◽  
...  

Author(s):  
Mona Semalty ◽  
Shikha Yadav ◽  
Ajay Semalty

As Ofloxacin is preferably absorbed from the upper part of the gastrointestinal tract and is readily soluble in the acidic environment of the stomach, the floating microspheres of ofloxacin were formulated to develop gastroretentive formulation. These floating microspheres release the drug in the stomach and upper gastrointestinal tract and thereby improve the bioavailability. In the present study, six formulations of ofloxacin hydrochloride were prepared as floating microspheres by solvent diffusion technique using polymers such as ethyl cellulose, polyvinyl pyrrolidone K-90 and poly vinyl alcohol in different ratios. The prepared microspheres were evaluated for different physicochemical tests such as particle size, percent drug entrapment, drug content uniformity, SEM, buoyancy test, and in vitro drug release studies. The results of all the physicochemical tests of all formulations were found to be satisfactory. In vitro floatability studies revealed that most of the microspheres (52.5% to 95.5%) were floatable. The in vitro drug release was found to be in the range of 39.64 to 93.64 % at the end of 6 hours. It is concluded that these floating microspheres can be selected for the development of gastroretentive drug delivery system of ofloxacin hydrochloride for potential therapeutic uses.


Author(s):  
Shubhrajit Mantry ◽  
Anna Balaji

Objective: The objective of this research work to design nasal microspheres of ropinirole hydrochloride (HCL) using different mucoadhesive polymers by adopting the suitable technique. To study the influence of formulation and process variables on microsphere formation and release characteristics. To perform the physicochemical characterization of the prepared microspheres. To carry out in vitro drug release studies and to explore the release behavior using various kinetic models.Methods: Experiments were performed with ropinirole HCL as a drug, chitosan, guar gum, carbopol 974P as a polymer. Span 80 and Tween 80 used light liquid paraffin, concentrated hydrochloric acid as solvent.Result: The in vitro drug release studies were conducted for all the formulations, that is, F1-F21 in 250 ml phosphate buffer pH 6.6 for 12 hrs. Among them, F15 showed 82.7±0.23% drug release and F21 showed 81.2% in 12 hrs in a sustained manner.Conclusion: Microspheres were formulated by emulsion solvent evaporation technique using different polymers. Apart from preventing nasal irritation, the microsphere possesses two major advantages over plain solutions, one is a high solubilization capacity for ropinirole HCL that exceeds their aqueous solubility and thus allows a reduction in the application volume. The results of this work indicate that intranasal microsphere of ropinirole may be beneficial for the treatment of Parkinson’s disease.


Author(s):  
Neeraj Agrawal ◽  
M.J. Chandrasekar ◽  
U.V. Sara ◽  
Rohini A.

A macromolecular prodrug of didanosine (ddI) for oral administration was synthesized and evaluated for in-vitro drug release profile. Didanosine was first coupled to 2-hydroxy ethyl methacrylate (HEMA) through a succinic spacer to form HEMA-Suc-ddI monomeric conjugate which was subsequently polymerized to yield Poly(HEMA-Suc-ddI) conjugate. The structures of the synthesized compounds were characterized by FT-IR, Mass and 1H-NMR spectroscopy. The prodrug was subjected for in-vitro drug release studies in buffers of pH 1.2 and 7.4 mimicking the upper and lower GIT. The results showed that the drug release from the polymeric backbone takes place in a sustained manner over a period of 24 h and the amount of drug released was comparatively higher at pH 7.4 indicating that the drug release takes place predominantly at the alkaline environment of the lower GIT rather than at the acidic environment of the upper GIT. This pH dependent sustained drug release behavior of the prodrug may be capable of reducing the dose limiting toxicities by maintaining the plasma drug level within the therapeutic range and increasing t1/2 of ddI. Moreover, the bioavailability of the drug should be improved as the prodrug releases ddI predominantly in the alkaline environment which will reduce the degradation of ddI in the stomach acid.


Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 110
Author(s):  
Muhammad Suhail ◽  
Chih-Wun Fang ◽  
Arshad Khan ◽  
Muhammad Usman Minhas ◽  
Pao-Chu Wu

The purpose of the current investigation was to develop chondroitin sulfate/carbopol-co-poly(acrylic acid) (CS/CBP-co-PAA) hydrogels for controlled delivery of diclofenac sodium (DS). Different concentrations of polymers chondroitin sulfate (CS), carbopol 934 (CBP), and monomer acrylic acid (AA) were cross-linked by ethylene glycol dimethylacrylate (EGDMA) in the presence of ammonium peroxodisulfate (APS) (initiator). The fabricated hydrogels were characterized for further experiments. Characterizations such as Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), Powder X-ray diffractometry (PXRD), and Fourier transform infrared spectroscopy (FTIR) were conducted to understand the surface morphology, thermodynamic stability, crystallinity of the drug, ingredients, and developed hydrogels. The swelling and drug release studies were conducted at two different pH mediums (pH 1.2 and 7.4), and pH-dependent swelling and drug release was shown due to the presence of functional groups of both polymers and monomers; hence, greater swelling and drug release was observed at the higher pH (pH 7.4). The percent drug release of the developed system and commercially available product cataflam was compared and high controlled release of the drug from the developed system was observed at both low and high pH. The mechanism of drug release from the hydrogels followed Korsmeyer–Peppas model. Conclusively, the current research work demonstrated that the prepared hydrogel could be considered as a suitable candidate for controlled delivery of diclofenac sodium.


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