chitosan

Nanoparticles  act  as  a  promising  system  for  targeted  delivery  of  drugs  and  as  an  effective  route  of  drug  administration.  In  this  study,  polysorbate  80  coated  nanoparticles  of  serratiopeptidase  were  formulated  and  aimed for  the  treatment  of  blood  clots  in  brain.  Serratiopeptidase exerts effective activity against blood clotting and has ability to dissolve non-living tissues,   blood clots, cysts, atherosclerotic clots. Different  nanoparticle  formulations  of  serratiopeptidase  were  prepared  with  different  concentrations  of  chitosan  and  tripolyphosphate  using  ionic  gelation  method.  The  nanoparticles were coated using polysorbate 80 and were characterized  and  evaluated  for  different  parameters  such  as  particle  size,  entrapment  efficiency,  zeta  potential and  transmission  electron  microscopy.  The  in  vitro  drug  release  of  prepared  nanoparticles  was  studied  in  phosphate  buffer  (pH 7.4).  The  results  indicated  that  the  developed  nanoparticle  formulation  could  be  established  as  a  promising carrier  for  active  targeting  into  brain  to  dissolve  blood  clots.

Present study aims to prepare and evaluate mucoadhesive microspheres by ionotropic gelation method. Among all the formulations M10 was selected as optimized formulation for mucoadhesive microspheres based on the evaluation parameters and drug release studies. In vitro release study of formulation M10 showed 97.11% 12 h in a controlled manner, which is essential for disease like peptic ulcer. The release order kinetics for M10 was best fit with the highest correlation coefficient was observed in Higuchi model, indicating diffusion controlled principle. The innovator Abygate conventional tablet shows the drug release of 97.23% within 1 h. FT-IR and DSC analyses confirmed the absence of drug-polymer interaction. The results obtained from evaluation and performance study of Gatifloxacin mucoadhesive microspheres that system may be useful to achieve a controlled drug release profile suitable for peroral administration and may help to reduce the dose of drug, dosing frequency and improve patient compliance when compared with marketed product.

In the present research work mucoadhesive microspheres of Cimetidine were prepared using Ionotropic gelation technique. All the microspheres were characterized for particle size, scanning electron microscopy, FT-IR study, DSC, percentage yield, drug entrapment, stability studies and for in vitro release kinetics and found to be within the limits. Among all the formulations M12 was selected as optimized formulation based on the physicochemical and release studies. In vitro drug release study of optimized formulation M12 showed 99.12% after 12 h in a controlled manner, which is essential for anti ulcer therapy. The innovator Cimetine conventional tablet showed the drug release of 96.15% within 1 h. The drug release of Cimetidine optimized formulation M12 followed zero order and Higuchi kinetics indicating diffusion controlled drug release.

The present investigation was carried out to develop colon targeted drug delivery system which consists of chitosan-chondroitin sulphate interpolymer complex as a binder containing rifaximin in the core coated with Eudragit E-100 and Eudragit RL-100.The  chitosan-chondroitin sulphate interpolymer complex was characterized by Fourier Transform Infrared Spectroscopy. In vitro release studies of coated tablets were carried out for 2 h in pH1.2 HCl buffer, 3h in pH 7.4 phosphate buffer and 19 h in pH6.8 phosphate buffer in the presence and absence of rat caecal content. A drug release of 27.13% was observed with uncoated tablets in HCl buffer pH 1.2, 80.56% of drug release in phosphate buffer pH 7.4 and 99.23% was observed in phosphate buffer pH6.8. Also tablets coated with Eudragit E-100 and Eudradgit RL-100 with different coat weight showed less than 10% of drug release in the stomach whereas same tablets showed 23.22%, 15%, 13.39%, 12.83% release of drug in pH 7.4 phosphate buffer and 73.26%, 75.91%, 72.23%, 71.93% release of drug in pH 6.8 phosphate buffer. Histopathology of rat colon after administration of Eudragit E-100 and Eudradgit RL-100 coated tablets containing chitosan-chondroitin sulphate interpolymer complex revealed marked reduction in acetic acid induced colitis in test group.

The goal of the present investigation was to formulate and evaluate chitosan and Eudragit Nanoparticles of Stavudine for antiviral therapy. Nanoparticles of Stavudine were prepared using chitosan, Eudragit S 100, liquid paraffin and Tween-20 using Emulsion droplet coalescence method. The concentration of the polymers Chitosan and Eudragit S 100 were selected based on the results on preliminary screening. The nanoparticles prepared were evaluated for morphology, loading efficiency and in-vitro release. The particle shape and morphology of the prepared Stavudine nanoparticles were determined by SEM analysis. The amount of Stavudine entrapment in the nanoparticles was calculated by the difference between the total amount of drug added to the nanoparticle and the amount of non-entrapped drug remaining in the aqueous supernatant. A Franz diffusion cell was used to monitor Stavudine release from the nanoparticles. The formulations CF1, CF2, EF2 and EF3 showed good drug release from the polymer. The percentage cumulative drug release after 12 hours was 75.54, 75.89, 78.86 and 76.42% respectively. However about 15% initial burst release was found at 1 hour in all formulations. EF2 released 78.86% of Stavudine 12 hours with a burst drug release nearly 14.86% of drug within the initial 1 hour. Formulations 4 out of 8showed good drug release from the polymer, the percentage cumulative drug release after 12 hours were in the range of 72-78 %. Among the four formulations EF 2 (1% Chitosan & 1.5 % EudragitS 100) showed maximum drug release in 12 hours diffusion study and good entrapment efficiency. In-vitro antiviral study revealed thatthe formulated nanoparticles were found to have good viral activity on viral cells in sustained manner.

To increase the bioavailability and short ocular residence time of Norfloxacin eye drops, aqueous solutions of drug in chitosan/ Pluronic (poloxamer) were prepared. Mixtures of solutions of Pluronic (5-17.5% w/w) with chitosan (0.1-0.6% w/w) were prepared.  The formulations so prepared were in the liquid state at 4°C while turned into a gel at the temperature of the Cul-de-sac. Naturals polymers i.e., Poloxamer was used as the polymer which exhibited the phase transition behavior and chitosan was used to improve residence time. Norfloxacin release was determined using a membrane less dissolution model in artificial tear solution up to 8 hours and the samples were analyzed spectrophotometrically at 277nm. The rheological behavior of solutions in response to dilution or temperature changes and also the phase change temperature (PCT) were determined. Antimicrobial effect of the solutions was studied in nutrient agar in comparison to all formulations of Norfloxacin using Pseudomonas aueroginosa, Staphylococcus aureus and E.coli by the agar diffusion test using the cup-plate technique. The formulation consisted of 15% Pluronic and 0.5% chitosan, with the highest release efficiency (73.46 ± 0.876%) and an acceptable mean release time, is suggested as a suitable ophthalmic preparation for sustained release of Norfloxacin.

An attempt has been made in the present research to formulate periodontal inserts of  Satranidazole (STZ) to increase residence time and prolong drug release. The periodontal inserts were prepared using chitosan, a natural biodegradable polymer. Chitosan inserts containing Satranidazole (10%, 20% and 30% to the weight of polymer) were prepared by solution casting method using 1% v/v acetic acid in water. Further inserts containing 30% Satranidazole were cross-linked by exposing to the vapours of 2% v/v glutaraldehyde in water for two different time period of 2 and 4 hours to retard the release of drug. FTIR and DSC studies revealed that there was no interaction between drug and polymers. The inserts were then evaluated for their physicochemical parameters like uniformity of thickness, weight, folding endurance, % moisture loss, tensile strength; drug content and in vitro drug release studies.  In vitro drug release data indicated that the films showed an initial burst release followed by sustained release of the drug. The drug-loaded films that were not cross linked had released the drug up to 10 days and the films which were cross linked for different duration showed a progressive fall in the release of the drug and extended up to 18 days.