Eudragit

The aim of the study was to develop colon targeted tablets of Sulfasalazine (SSZ) by wet granulation method using 33 Response surface method with design of experiment software and Eudragit RS 100, Eudragit RL 100-55, Ethyl cellulose and PVP K-30 as pH dependent polymers. All the formulations (F1 to F27) were evaluated for the physicochemical parameters and were subjected to in vitro drug release studies. The amount of Sulfasalazine released from tablets at different time intervals was estimated by UV spectrophotometer. The formulation F17 shown 98.21±1.15 of Sulfasalazine after 24 h, whereas marketed product drug release was 96.21±1.87 after 1 h. The results of the study showed that formulation F17 is the best formulation on the basis of drug release and other evaluation parameters. From in vivo bioavailability studies, after oral administration of colon targeted tablet containing 500 mg Sulfasalazine, the Cmax, Tmax, and AUC0–∞ of optimized formulation and marketed product was found to be 684.31±4.03 ng/mL, 6.01±0.04 h, 4525.12±2.02 ng*h/ mL and 702.26±3.23 ng/mL, 1.50±0.01h, 3335.18±2.02 ng*h/mL respectively. Cmax, Tmax and AUC values of optimized formulation were found to be significantly higher than of marketed product. The pH dependent system is a promising vehicle for preventing rapid hydrolysis in gastric environment and improving oral bioavailability of Sulfasalazine in the effective management of colon related diseases.

Felodipine is an effective calcium channel blocker, mainly used in the treatment of hypertension and angina pectoris.  To overcome the low oral bioavailability of felodipine, the present work was designed to develop transdermal therapeutic system for felodipine using the polymer blend of eudragit RL 100 (ERL) / RS 100 (ERS) by solvent casting method. Dibutyl phthalate (DBP) and oleic acid (OA) were used as plasticizer and permeation enhancer respectively. Incorporation of DBP improved the flexibility, folding endurance and handling properties of the films. Increasing the concentration of ERL, and the presence of plasticizer were found to increase the in vitro drug release of the films.  The patches were also evaluated for ex vivo skin permeation using human cadaver skin. The presence of OA produced significant increase in the flux and permeability constant. The formulation with ERL: ERS ratio 4:1, 5% w/w OA as permeation enhancer and 20% w/w DBP as plasticizer showed the best results which exhibited the cumulative percentage of drug release of 75.73 ± 2.179 % and the cumulative amount of drug permeation across skin of 4321 ± 11.533 µg/cm2 in 24 hrs. Drug-excipient interaction studies were carried out using DSC and IR technique; films indicated no chemical interaction between drug and excipients. The results of the skin irritation studies showed no noticeable irritancy on rabbit skin indicating the skin compatibility of the drug as well as polymer.  An attempt was made to develop the complete transdermal system of the drug by using backing membrane and release liner.

Olmesartan medoxomil is an angiotensin II antagonist used as an antihypertensive drug which has poor oral bioavailability. Hence, an attempt was made to prepare and evaluate mucoadhesive buccal films containing Olmesartan medoxomil as model drug. Various mucoadhesive buccal films were prepared by employing HPMC alone, and in combination with Eudragit RL100, Carbapol 934, Ethyl cellulose were prepared by solvent casting method using ethanol , water and acetone as solvents, tween 80 as solubilising agent and glycerine as plasticizer. The prepared mucoadhesive buccal films were evaluated for their physic-chemical parameters such as thickness uniformity, weight uniformity, folding endurance, drug content , surface pH, swelling index, bioadhesion, percentage moisture loss and uptake, vapor transmission rate. The formulations exhibited good results. In – vitro drug release studies were conducted for OLM loaded films in phosphate buffer (pH 6.8) solution. The drug release was in the range of 67 to 90 % in 6hrs.. Stability studies were carried out with selected formulation. In- vivo release was evaluated in rabbits by patch test and it showed good correlation with the in-vitro release data. Drug release was found to be diffusion following zero order as per kinetic studies.

  Stress is a biological response to aversive conditions that tend to threaten or perturb the homeostasis of the organisms. Stress is one of the basic factors in the etiology of number of diseases and stress has been postulated to be involved in pathogenesis of various diseases, such as psychiatric disorders like depression and anxiety, immune suppression, endocrine disorder like diabetes mellitus, impotency, cognitive dysfunction, peptic ulcer, ulcerative colitis and cardiovascular disorder like atherosclerosis and hypertension. So a mixture of herbal extracts like Arjuna, Ashwagandha, Brahmi and Shankhapushpi in equal ratios was microencapsulated using different types of wall polymers by non solvent addition method. Microcapsules were evaluated for their percentage yield, percentage actual drug content, percentage extract entrapment efficiency, flowability and drug release kinetics. Kollicoat SR 30 D and aluminium stearate were observed as effective in prevention of particle aggregation during phase separation.  Microcapsules were shown controlled drug release pattern for 12 hours due to the presence of Eudragit RS 100 and Eudragit RL 100. Both these wall polymers are responsible for controlling the drug release from microcapsules through diffusion in phosphate buffer medium having pH 7.4.