Formulation And In-Vitro Evaluation Of Theophylline Hydrochloride Effervescent Floating Tablets: Effect Of Polymer Concentration On Tablet Buoyancy

Objective: This study was undertaken to formulate a floating drug delivery system of theophylline hydrochloride using different concentrations of a chosen polymer and then investigate how polymer concentration affects buoyancy and drug release properties of the tablets. Methods: Hydroxypropyl methylcellulose (HPMC) at different concentration levels of 15% (F1), 20% (F2) and 30% (F3) was used to form the three formulation batches of floating tablets. Wet granulation method was used for the granule preparation while Sodium bicarbonate and citric acid were used as the gas generating agent. The physical properties of the granules and the floating tablets were evaluated. Also determined were the physicomechanical properties, buoyancy and swelling characteristics of the tablets. The in vitro drug release study was carried out according to the USP I (basket method) for 8h in 900 ml 0.1N HCl at 50 rpm. Samples withdrawn at the regular predetermined time were analyzed spectrophotometrically at a wavelength of 271 nm and data obtained statistically analyzed by one-way analysis of variance (ANOVA). The differences between means were considered significant at P<0.05. Results: The result showed that polymer (HPMC) concentration significantly (p>0.05) increased swelling index and improved floating lag time, it had no significant effect on the total floating time. Percentage drug release at the end of 8 h was 100%, 98.2% and 96.13% for formulation F1, F2 and F3, respectively. All three formulations followed the Higuchi drug release kinetics model and the mechanism of drug release was the non Fickian diffusion with exponents of 0.46, 0.51 and 0.56 for the respective batch. Conclusion: Batch F3 gave a better-controlled drug release and floating properties in comparison to batch F1 and F2 thus Polymer concentration influenced the onset of floating and controlled the release of Theophylline.

Gastro-Retentive Floating Matrix Tablets of Cefpodoxime Proxetil.

The present work aims at the development and evaluation of Floating matrix tablets of Cefpodoxime Proxetil were undertaken to prolong gastric residence time. A visible Spectrophotometric method has been employed for the estimation of Cefpodoxime Proxetil at 263 nm and Beer’s law is obeyed in the concentration range of 5-40 μg/ml. Total 7 formulations (B1-B7) were prepared using guargum with carbopol 934P was used in different concentrations. Fourier transform Infrared spectroscopy confirmed the absence of any drug/polymers/excipients interactions. The tablets were prepared by direct compression technique, using polymer such as hydroxy propyl methyl cellulose (HPMC K4M), guargum and carbopol 934P in different combinations with other standard excipients like sodium bicarbonate and lactose. Tablets were evaluated for physical characterization viz. hardness, friability, swelling index, floating capacity, thickness and weight variation. Further tablets were evaluated in-vitro drug release for 12 hr. The effect of polymer concentrations on buoyancy and drug release pattern was also studied. In-vitro drug release mechanism was evaluated by PCP V-3 software. Carbopol 934P had a negative effect on the floating properties also decreased the drug release. A lesser FLT and a prolonged floating duration could be achieved by varying the amount of effervescent and using different polymer concentrations. The entire matrix tablets showed significantly greater swelling index, exhibited controlled and prolonged drug release profiles and some floated over the dissolution medium for more than12 hr. The paddle speed affected the floating lag time and floating duration it had a negative effect on the floating properties. The optimized formulation followed the higuchi release model and showed non-fickian diffusion mechanism. It also showed no significant change in physical appearance, drug content, floatability or in-vitro dissolution pattern after storage at 45 oC at 75 % RH for three months.

Formulation and evaluation of Salbutamol sulphate microspheres by solvent evaporation method.

Salbutamol sulphate (SS) loaded microspheres were prepared by solvent evaporation method with combination of hydroxy propyl methyl cellulose and Carbopol polymers in various proportions. A total of eleven formulations were prepared i.e. E1, E2, E3, E4, E5, E6, E7, E8, E9, E10 and E11.The particle size of all the formulations were ranged between 110±0.02 and 183±0.02μm. The entrapment efficiency was ranged between 68.3±0.01 and 94.9±0.02%. Based on above parameters four formulations were selected i.e. E5, E8, E9 and E10 for further studies like micromeretic properties, swelling index and in-vitro release profile. It was confirmed with the results of micromeretic property that all the selected formulations showed good flow property. Release data were analyzed based on Highuchi kinetics and Korsmeyer-Peppas equation and all the selected formulations showed good fit to Highuchi model. Stability studies showed almost negligible changes in particle size, entrapment efficiency and drug release throughout the study period.