ABSTRACT
A locally produced starch from Saudi cultivated corn was evaluated as a tablet excipient and compared with an imported corn starch that is produced internationally and used by a local leading pharmaceutical company. The comparative evaluation included: quality control, physical characterization, viscosity of starch paste, binding properties during granulation and disintegrating power when used in tablet preparation. Theophylline was used as a model drug. The two starches were subjected to evaluation after freeze and spray drying processes. Both starches showed similar particle sizes with poor flowability although the flow properties were in favor of the imported starch. Enhanced flowability was noticed in both starches upon freeze drying and spray drying. Granules prepared by wet granulation using the imported starch were less friable indicating good binding ability compared to the Saudi starch. Interestingly, tablets made from the Saudi starch disintegrated faster and released the drug faster than those made from the imported starch. Thus, it was concluded that although imported starch had more binding capacity than Saudi starch, yet Saudi starch has more disintegrating power and produced immediate drug releasing tablets. These findings may be considered for possible utilization of locally produced Saudi starch as a tablet excipient, in future
Subject(s)
Tablets , Theophylline , Freeze Drying , Drug EvaluationABSTRACT
Theophylline sustained release microspheres were prepared by applying the non-solvent addition method. The in-vitro release of the drug from the prepared microspheres of different size ranges [= 300, 300-600, 600-800, 800-1000 and 1000-1250 micro m] was studied. The effects of different ethylcellulose: theophylline ratios [1:2, 1:1 and 2:1] and different plasticizer [diethylphthalate] concentrations [10, 20 and 30% v/w] on theopylline release were also investigated. At different ethylcellulose: theophylline ratios [1:1, 2:1 and 1:2], the release of the drug decreased significantly when the polymer content was increased and the drug loading was decreased. Also, the release was significantly decreased [P<0.05] with increasing plasticizer concentration from 10 to 30%, with no significant difference between un-plasticized and 10% plasticizer
Subject(s)
Cellulose/analogs & derivatives , Microspheres , Delayed-Action Preparations , Plasticizers , Particle Size , KineticsABSTRACT
Theophylline sustained release microspheres were successfully prepared by applying the non-solvent addition method. The prepared microspheres were subjected to irradiation with Gamma rays at a dose of 100 kGy. The in-vitro release rate of the drug from the irradiated microspheres was studied and the effect of annealing after radiation was investigated. The results showed that the release of theophylline from microspheres was faster from the irradiated microspheres compared to the non-irradiated ones, that is because of the effect of radiation on both the drug and the polymer crystal lattice. The polymeric layer played a significant role of protecting the drug from being affected with Gamma rays. That effect retrieved after heating the irradiated microspheres to temperature [65 and 120°C] for 15 and 24 hours respectively