Guar gum

The aim of the present study was to develop sustained release formulation of Isoniazide to maintain constant therapeutic levels of the drug for over 12 hrs. Various polymers such as Guar gum,HPMCK100 M,PEG 6000 AND Carbopol 934 p were employed as polymers. Isoniazide dose was fixed as 100 mg. Total weight of the tablet was considered as 400 mg. Polymers were used in the concentration of 100, 150 and 200 mg concentration. All the formulations were passed various physicochemical evaluation parameters and they were found to be within limits. Whereas from the dissolution studies it was evident that the formulation (F6) showed better and desired drug release pattern i.e.,96.10 % in 12 hours. It followed zero order release kinetics mechanism.

The aim of the present study was to develop sustained release formulation of Verapamil Hydrochloride to maintain constant therapeutic levels of the drug for over 12 hrs. Various grades of HPMC polymers, Guar gum and Xanthan gum were employed as polymers. Verapamil Hydrochloride dose was fixed as 120 mg. Total weight of the tablet was considered as 400 mg. Polymers were used in the concentration of 60, 120 and 180 mg concentration. All the formulations were passed various physicochemical evaluation parameters and they were found to be within limits. Whereas from the dissolution studies it was evident that the formulation (F6) showed better and desired drug release pattern i.e., 96.10 % in  12 hours containing Guar gum polymer in the concentration of 180mg . It followed zero order release kinetics. For the optimized formulation alcohol effect has been studied by using various concentrations of alcohol in dissolution medium. As the concentration of alcohol increases the sustained action of polymer was decreased. Hence it was concluded that alcohol has significant effect on drug release pattern.

The objective of this study is to select between native and treated guar gum as tablet disintegrant and to explore the possible influences of disintegrant content and production method on different tablet attributes using promethazine-HCl as a model drug. Tablet batches were formulated according to 23 full factorial design in which each of the selected factors was investigated at two possible levels for their individual and combined influences on tablets properties. Native and treated gum were considered for guar gum type, guar content was examined at 2 and 8%w/w whereas dry and wet granulation were selected as levels for tablets production method. Guar gum content was demonstrated to affect weight variation, thickness variation and friability properties of different tablet batches (p ranged 0.012-0.038). Guar gum type was also established to influence weight and thickness variation as well as disintegration and drug dissolution properties (p ranged 0.025-0.039). Influences of production method on weight variation, thickness variation, friability, disintegration and drug dissolution properties were found to be considerable (p< 0.05, for all effects). None of the investigated factors has measured a significant effect on tablet hardness property (p ranged 0.4511- 0.9214 for the effects of all factors). Compared to native guar gum, treated guar gum was found to be more efficient as a tablet disintegrant (p= 0.039). Formulations including 2 or 8% w/w treated guar gum and processed by dry granulation were found to yield tablets with average short disintegration time (5.0 ± 0.9 min) and enhanced dissolution efficiency (0.805 ± 0.005).

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.

Colon specific tablets of Oxaliplatin combined with anti-inflammatory agents, Diclofenac sodium were prepared using guar gum as matrix carriers in varying concentrations from 40% to 65%. The drug combination in the tablet was estimate simultaneously using newly developed and validated UV derivative spectroscopy method. In vitro drug release profile was studied in changing media method, first in 0.1N HCl for two hours followed by 3 hours in phosphate buffer media, pH 7.4 (PB7.4) and in simulated colon fluid (phosphate buffer pH 6.8 added with rat ceacal content) (SCF) for 19 hours. 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 diclofenac sodium combination with 60% w/w Gaur gum showed a total release of ~66% of Oxaliplatin and ~53% of Diclofenac sodium after 24 hrs. The colon tissue homogenate studies conducted after oral administration of the optimized matrix tablet in New Zealand Rabbits showed 156 µg oxaliplatin and 96 µg Diclofenac sodium recovery in 24 hours.  X-ray Images of matrix tablets containing barium sulphate in Rabbit showed tablets to be intact in small intestine (6 hours after administration) but were diffused and spread out in large intestine and colon confirming enzyme mediated erosion of the tablet in these regions. 

  Matrix tablets of Indomethacin were prepared by wet granulation method. Guar gum as a carrier, 10% starch paste, HPMC, citric acid and the mixture of talc and magnesium stearate at 2:1 ratio were used. Coating was carried out by using 10% Eudragit L 100. All the prepared formulations were evaluated for hardness, drug content uniformity, stability study and were subjected to in vitro drug release studies in rat caecal contents. The highest in vitro dissolution profile at the end of 24 h was shown by IF6 followed by IF7, IF8. The other formulation IF4, IF3, IF2 and IF1 were failed to target in colon and these formulation releases the majority of drug within 10 h of study. It may be due to the less proportion of guar gum to retard the drug release.  The colon targeted matrix tablet of Indomethacin showed no change either in physical appearance, drug content or in dissolution pattern after storage at 30˚ C/ 65±5 % RH for 2 months.   Key words: Colon targeted, Eudragit L-100, Guar gum, Indomethacin, Matrix tablets, Rat caecal content.