Controlled release.

The purpose of this study was to develop chitosan based anastrozole nanoparticles for treatment of breast cancer. An ionic gelation method was used to prepare anastrozole controlled-release nanoparticles. A 32 full factorial design was employed. Experimental variables such as concentration of CS and cross-linking agent sodium TPP were varied to study their effect on drug entrapment efficiency and release rates of drug from nanoparticles. Fourier transform infrared spectroscopic (FTIR) analysis and differential scanning calorimetry (DSC) were employed to determine any interactions between drug and polymer. The FTIR studies revealed no chemical interaction between the drug and the polymer. Entrapment efficiency of nanoparticles ranged between 51.51 ± 0.81 % to 84.35 ± 1.06 %.In-vitro release studies were performed in phosphate buffer saline of pH 7.4. A slow release of anastrozole up to 72 h was observed. Mean particle size of nanoparticles ranged between 1635 nm to 72.30 nm with mean particle size of 273.6 nm, while zeta potential 0.52 mV. DSC results indicated that the anastrozole entrapped in the nanoparticles existed in an amorphous or disordered-crystalline status in the polymer matrix. Scanning electron microscopy was done to study the surface morphology. Results revealed that more spherical shaped particles with possible aggregation. The highest correlation coefficients were obtained for the Higuchi model, suggesting a diffusion mechanism for the drug release. The results demonstrated that anastrozole nanoparticles with chitosan could be an alternative delivery method for the long-term treatment of breast cancer.

Tablets of Oxaliplatin combined with Curcumin was prepared for colon specific delivery using guar gum as matrix carriers in varying concentrations from 40% to 65%. The drug concentration in the tablet was estimated by the newly developed and validated UV derivative spectroscopy method. In vitro drug release profile was studied in changing media method (0.1N HCl, phosphate buffer media, pH 7.4 and simulated colon fluid containing phosphate buffer pH 6.8 added with rat ceacal content). The drug release profiles from PB7.4 and simulated colon fluid were found to be dependent on the gaur gum concentration. Matrix tablets of Oxaliplatin and Curcumin combination showed ~65% of Oxaliplatin and 37% of curcumin release. The colon tissue homogenate studies conducted after oral administration of the optimized tablets showed the recovery of 167.5µg Oxaliplatin and 80µg. curcumin. X-ray Images of matrix tablets containing barium sulphate in Rabbit showed tablets to be intact in small intestine (3 hours after administration) but were diffused and spread out in large intestine and colon later confirming enzyme mediated erosion of the tablet in these regions. Keywords- Oxaliplatin, Curcumin, Matrix tablets, Guar gum, Colon specific delivery, Controlled release.