Asian Journal of Pharmaceutical and Clinical Research Vol.2 Issue 3, July-September 2009
tablet shows no evidence of capping, cracking, cleavage and breakage after tumbling in the Rochi Block friabilater. The mean value of the hardness and the thickness for entire batch of core tablets was found to be 2.94 mm and hardness 8-9 Kg. The presence of optimum amount of moisture (2-3 %) and PVPK-30 in the precompressed granules were the contributing factors for the low friability and good hardness of the tablets. The coated tablets passed the disintegration test as they were found to disintegrate in 1 min 4 seconds. The quick disintegration time of the tablets can be attributed to the presence of the super disintegrant crospovidone in optimum concentration in the formula.
% Drug released
T1 T2 T3 T4
continuous with no spray system blocking during the coating. The detailed processed conditions are out lined in the Table 2.
The dissolution profile of the coated tablets with different weight gain is displayed in the Table 3. In case of normal PVA based coating (without tween 80) shows limited drug release which is increased in the tablets coated with 3 % tween in coating composition. Approximately 15-25% rise in dissolution is observed in first 20 minutes. Where in case of tablets with 6 and 10 % weight gain of tween 80, there is no further increase in dissolution rate. The details are given in Table III. The results collectively indicate that, Tablet compression and aqueous coating can be applied to successfully develop a formulation. A coat weight including 3 % tween 80 in coating was just sufficient to enhance the solubility and dissolution rate of the tablets. Dissolution profile of tablets is shown in Fig.1
FIG.1-Dissolution Profile of Tablets In pH 6.8 Phosphate Buffer, USP II, 50 Rpm, 900 ml
T1-coating without Tween 80, T2-3 % Tween 80, T3-6 % Tween 80, T4-10 % Tween 80
The batch of the tablets was found to pass the weight variation test with an average tablet weight of 150 mg. The core tablets passed the content uniformity test with an average assay value 98.4 %. The uniformity in content could be related to the low weight variation of the core tablets which could be due to the narrow size distribution and free flowing nature of the precompressed granules. The tablet shows no signs of sticking, binding during the compression. The aqueous coating procedure was adopted to apply the PVA based coating on the core tablets. Triethyl citrate is used at a concentrate of 10 % w/w to lower the glass transition temperature and promote formation of a good elastic film. The coating dispersion flow during the coating process was
The prepared tablet gives benefit in terms of patient compliance, rapid onset of action, low side effect and good stability which make these tablets popular as a dosage form for the treatment of hypertension.
Mollendorff EV, Reiff K, Neugebauer G: Pharmacokinetics and bioavailability of carvedilol, a vasodilating beta-blocker. Eur J Clinical Pharm1987; 33:511-513.
Sharma S, Gupta GD, Jain CP, Naruka PS: Development and Evaluation of Carvedilol Fast Dissolving Tablets Using Superdisintegrant and Solid Dispersion Technique. The Pharma review 2007.
Ubaidulla U, Reddy MV, Ruckmani K, Ahmad F, Khar RK: Transdermal Therapeutic System of Carvedilol: Effect of Hydrophilic and Hydrophobic Matrix on In