Nanoparticles of poly(lactide)/vitamin E TPGS copolymer for cancer chemotherapy: Synthesis, formulation, characterization and in vitro drug release

Biomaterials ◽  
2006 ◽  
Vol 27 (2) ◽  
pp. 262-270 ◽  
Author(s):  
Z ZHANG ◽  
S FENG
2018 ◽  
Vol 544 (2) ◽  
pp. 380-391 ◽  
Author(s):  
Phillip Dixon ◽  
Richard C. Fentzke ◽  
Arnab Bhattacharya ◽  
Aditya Konar ◽  
Sarbani Hazra ◽  
...  

Author(s):  
GAGANDEEP SINGH ◽  
NAVJOT SINGH ◽  
RANDEEP KUMAR ◽  
NEENA BEDI

Objective: The present study entails the development of nevirapine (NVP)-loaded solid dispersions for improvement of solubility and in vitro profile. Methods: Solid dispersions were prepared through blending with a hydrophilic polymer and Vitamin E tocopherol polyethylene glycol succinate (TPGS) using the solvent evaporation method. The optimized formulations were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, and morphological investigations by scanning electron microscopy. The optimized formulation was converted into fast dissolving tablets (FDTs) through direct compression technique and was characterized for pre- and post-compression parameters. Both amorphous dispersions and FDTs were evaluated for in vitro drug release. Results: NVP showed pH-dependent solubility in different pH media. Above 0.002% w/v Vitamin E TPGS, a linear relationship was observed between the NVP solubility and Vitamin E TPGS concentration. According to the study, the most suitable formulation was NVP:Vitamin E TPGS (1:0.75) in 30 ml solvent with a drug release of 82.96% in 2 h. The analysis of dissolution data of optimized formulation indicated the best fitting with the Higuchi model. FDTs exhibited faster drug release of about 50% in 5 min indicating desired attributes for the immediate dosage form. Conclusion: The present study vouches for better in vitro profile of NVP from solid dispersion based FDTs.


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.


Author(s):  
Dillip Kumar Behera ◽  
Kampal Mishra ◽  
Padmolochan Nayak

In this present work, chitosan (CS) crosslink with polyaniline (PANI) with montmorilonite (MMT) called as (CSPANI/MMT) and CS crosslink with PANI without MMT called as (CS-PANI) were prepared by employing the solution casting method. Further the formation of nanocomposites CS-PANI/MMT and CS-PANI were investigated using XRD, FTIR, SEM and tensile strength. Water uptake and swelling ratio of the CS-PANI and CS-PANI/MMT were found to decrease with increase in concentration of clay. Mechanical properties of the CS-PANI and CS-PANI/MMT were assessed in terms of tensile strength and extensibility using texture analyzer. Increase in tensile strength and reduction in extensibility was reported with increase in the nanoclay content. In vitro drug release study on CS-PANI and CS-PANI/MMT indicated pronounced sustained release of doxorubicin by the incorporation of clay particles in the CS polymer matrix. Overall CSPANI/MMT nanocomposite films exhibited improved mechanical and sustained drug release properties than CS-PANI.


Author(s):  
Kranthi Kumar Kotta ◽  
L. Srinivas

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.


Author(s):  
Bipul Nath ◽  
Santimoni Saikia

In the present investigation, sodium alginate based multiparticulate system overcoated with time and pH dependent polymer was studied in the form of oral pulsatile system to achieve pulsatile with sustained release of aceclofenac for chronotherapy of rheumatoid arthritis seven batches of micro beads with varying concentration of sodium alginate (2-5 %) were prepared by ionotropic-gelation method using CaCl2 as cross-linking agent. The prepared Ca-alginate beads were coated with 5% Eudragit L100 and filled into pulsatile capsule with varying proportion of plugging materials. Drug loaded microbeads were investigated for physicochemical properties and drug release characteristics. The mean particle sizes of drug-loaded microbeads were found to be in the range 596±1.1 to 860 ± 1.2 micron and %DEE in the range of 65-85%. FT-IR and DSC studies revealed the absence of drug polymer interactions. The release of aceclofenac from formulations F1 to F7 in buffer media (pH 6.8) at the end of 5h was 65.6, 60.7, 55.7, 41.2, 39.2, 27 and 25% respectively. Pulsatile system filled with eudragit coated Ca-alginate microbeads (F2) showed better drug content, particle size, surface topography, in-vitro drug release in a controlled manner. Different plugging materials like Sterculia gum, HPMC K4M and Carbopol were used in the design of pulsatile capsule. The pulsatile system remained intact in buffer pH 1.2 for 2 hours due to enteric coat of the system with HPMCP. The enteric coat dissolved when the pH of medium was changed to 7.4. The pulsatile system developed with Sterculia gum as plugging material showed satisfactory lag period when compared to HPMC and Carbopol.


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