ABSTRACT
The sustained release microspheres of theophylline were formulated using non-solvent addition technique. The in-vitro dissolution of the drug from the fabricated microspheres that having size ranges of 300-600, 600-800 and 800-1000 [micro]m was tested The release of theophylline was extended over 8 hrs and it was found that the drug release decreased nonsignificantly as the particle size increased [p>/=0.05]. incorporating theophylline-containing microspheres into suppository formulation using polyethylene glycol base resulted in a slight increase in dissolution rate, but still in a sustained release pattern over 8 hrs. In-vivo study of the prepared suppositories on beagle dogs revealed that the peak of theophylline serum concentration C[max] [mean +/- S.D] was 11.1+0.3 [micro]g/mL. It was also found that AUC [0-24hrs] value averaged 154.7 +/- 20.3 [micro]g-h/ml. The median peak time [T[max]] was 3.0 hrs and MRT was 13 hrs indicating a sustained effect
ABSTRACT
Piroxicam is a potent nonsteroidal anti-inflammatory drug associated with many side effects when taken orally. An attention was paid in this work to formulate and characterize piroxicam containing polymer films for dermal use. The used polymers were Eudragit types namely Eudragit RL100, RS100, L100 and Eudragit S100. In this study, medicated films consisting of drug and carrier were prepared. The carrier consisted of one or two polymers. The physicochemical characterization was done by IR spectroscopy, DSC and X-Ray diffractometry for both piroxicam polymeric films and their corresponding physical mixtures as well as the untreated drug and polymer powders to investigate the drug polymer interaction. The results indicate presence of molecular interactions between piroxicam and both Eudragit L100 and Eudragit S100 and no interactions were found between piroxicam and Eudragit RL100 or Eudragit RS100. In-vitro drug release from Eudragit films was studied It is found that the drug release from hydrophilic polymers is faster than that from hydrophobic ones
Subject(s)
Chemistry, Pharmaceutical , Polymers , Administration, Cutaneous , Spectrum Analysis/methods , X-Ray Diffraction/methodsABSTRACT
The aim of this study was the preparation of diclofenac sodium microcapsules using cellulose acetate as a polymer and polyvinyl acohol as an emulsifying agent by solvent evaporation technique. Preliminary experiments were carried out to determine practically the volume range of both the external phase, the internal organic phase, the concentration range of emulsifier and the drug to polymer ratio. The prepared microcapsules were evaluated for their morphology and surface structure, average particle size, yield, drug loading efficiency, and their release pattern. The results of these trials revealed that diclofenac sodium-cellulose acetate microcapsules were successfully prepared applying the solvent evaporation technique. The characteristics of the produced microcapsules were highly affected by the different formulation parameters. Changing the polymer content didn't affect the morphology of the produced microcapsules. The microcapsules were discrete, spherical and freely flowing. The increase in the polymer amount increased the mean particle size and decreased the yield of the microcapsules due to the increase in the internal phase viscosity. The drug loading efficiency was significantly increased with the increase in methylene chloride-acetone volume. The condensed monolayer of polyvinyl alcohol was not achieved at concentrations below 0.5%. Above this concentration] the increase in polyvinyl alcohol content decreased both the mean particle diameter end the percentage yield of the microcapsules. The release of diclofenac sodium from cellulose acetate microcapsules was pH dependent. The drug was released faster in the alkaline medium compared to acidic medium