C. S. Satish

Bio: C. S. Satish is an academic researcher. The author has contributed to research in topics: Chitosan & Self-healing hydrogels. The author has an hindex of 6, co-authored 6 publications receiving 192 citations.

Synthesis and characterization of carboxymethyl chitosan hydrogel: Application as site specific delivery for lercanidipine hydrochloride

Abstract: In the present study, carboxymethylchitosan (CMCS) was prepared from chitosan, crosslinked with glutaraldehyde and evaluated in vitro as a potential carrier for site specific drug delivery of lercanidipine hydrochloride (LERH). LERH was incorporated at the time of crosslinking of CMCS. The chitosan was evaluated for its degree of deacetylation (DD) and average molecular weight, which were found to be 84·6% and 3·5 × 104 Da, respectively. The degree of substitution on prepared CMCS was found to be 0·68. All hydrogel formulations showed more than 86% and 77% yield and drug loading, respectively. The swelling behaviour of prepared hydrogels were checked in different pH values, 1·2, 6·8 and 7·4, indicated pH responsive swelling characteristic with very less swelling at pH 1·2 and quick swelling at pH 6·8 followed by linear swelling at pH 7·4 with slight increase. In vitro release profile was carried out at the same conditions as in swelling and drug release was found to be dependent on swelling of hydrogels and showed biphasic release pattern with non-fickian diffusion kinetics at higher pH. The carboxymethylation of chitosan, entrapment of drug and its interaction in prepared hydrogels were checked by FTIR, 1H-NMR, DSC and p-XRD studies, which confirmed formation of CMCS from chitosan and absence of any significant chemical change in LERH after being entrapped in crosslinked hydrogel formulations. The surface morphology of formulation S6 was checked before and after dissolution, revealed open channel like pores formation after dissolution.

Stomach-specific drug delivery of 5-fluorouracil using ethylcellulose floating microspheres.

Abstract: A multiple-unit-type oral floating dosage form (FDF) of 5-Fluorouracil (5-FU) was developed to prolong gastric residence time for the treatment of stomach cancer. The floating microspheres were prepared by solvent evaporation method. The prepared microspheres were characterized for their micromeretic properties, floating behavior and entrapment efficiency; as well by Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), thin layer chromatography (TLC) and scanning electron microscopy (SEM). The in vitro release studies and floating behavior were performed in HCl buffer pH 1.2, Phosphate buffer pH 4.5 and in Simulated Gastric Fluid (SGF). The best fit release kinetics was achieved with Higuchi plot. The yields of preparation were very high and low entrapment efficiencies were noticed with larger particle size for all the formulations. Mean particle size, entrapment efficiency and production yield were highly influenced by polymer concentration. It was concluded from the present investigation that porous Ethylcellulose microspheres are promising controlled release as well as stomach targeted carriers for 5-FU.

Synthesis and characterization of carboxymethyl chitosan hydrogel: application as pH-sensitive delivery for nateglinide

Abstract: In current research, chitosan was reacted with mono-chloroacetic acid under alkaline condition to prepare carboxymethyl chitosan (CMCTs). The degree of substitution (Ds) on prepared CMCTs was found to be 0.68. CMCTs was used as a potential carrier for pH specific delivery of nateglinide after crosslinked using glutaraldehyde in presence of nateglinide. The average molecular weight and degree of deacetylation (DD) of chitosan were found to be 3.5x104 Da and 84.6% respectively. High yield (82%) and loading of drug (75%) were found in the developed hydrogel formulations. pH responsive swelling behavior of prepared hydrogels was checked using different pH values (1.2, 6.8 and 7.4). The study indicated very less swelling at pH 1.2 (for first 2 h) and quick swelling at pH 6.8 (for next 3 h) followed by linear swelling at pH 7.4 (for next 7 h) with slight increase. In vitro release profile of hydrogels showed biphasic release pattern dependent on swelling behavior. The release pattern was found to be non-fickian diffusion kinetics at higher pH. FTIR, 1H-NMR, DSC and p-XRD studies were carried out to confirm the formation of CMCTs, drug entrapment and its possible interaction in formulations. These studies revealed that no chemical change was found in nateglinide during preparation of hydrogel formulations. Scanning Electron Microscopy (SEM) was used to study the surface morphology of prepared hydrogels before and after dissolution which revealed pores formation after dissolution.

Preparation and characterization of 5-fu loaded microspheres of eudragit and ethylcellulose

Abstract: In the present investigation, 5-fluorouracil loaded microspheres of Eudragit (RS 100, RL 100 and RSPO) and ethylcellulose were prepared. �O/O solvent evaporation� technique was used for preparation of microspheres using (methanol + acetone)/liquid paraffin system. Magnesium stearate was used as the droplet stabilizer and n-hexane was added to harden the microspheres. The prepared microspheres were characterized for their micromeretic properties and entrapment efficiency; as well by Fourier transform infrared spectroscopy (FTIR) and thin layer chromatography (TLC). Photomicrographs were taken to study the shape of microspheres. The best fit release kinetics was achieved with Higuchi plot. Mean particle size, entrapment efficiency and production yields were highly influenced by the type of polymer and polymer concentration. It is concluded from the present investigation that various Eudragit and Ethylcellulose are promising controlled release carriers for 5-FU.

Antimicrobial hydrogels: promising materials for medical application.

Abstract: The rapid emergence of antibiotic resistance in pathogenic microbes is becoming an imminent global public health problem. Local application of antibiotics might be a solution. In local application, materials need to act as the drug delivery system. The drug delivery system should be biodegradable and prolonged antibacterial effect should be provided to satisfy clinical demand. Hydrogel is a promising material for local antibacterial application. Hydrogel refers to a kind of biomaterial synthesized by a water-soluble natural polymer or a synthesized polymer, which turns into gel according to the change in different signals such as temperature, ionic strength, pH, ultraviolet exposure etc. Because of its high hydrophilicity, unique three-dimensional network, fine biocompatibility and cell adhesion, hydrogel is one of the suitable biomaterials for drug delivery in antimicrobial areas. In this review, studies from the past 5 years were reviewed, and several types of antimicrobial hydrogels according to different ingredients, different preparations, different antimicrobial mechanisms, different antimicrobial agents they contained and different applications, were summarized. The hydrogels loaded with metal nanoparticles as a potential method to solve antibiotic resistance were highlighted. Finally, future prospects of development and application of antimicrobial hydrogels are suggested.