فهرست مطالب سحر چنگیزی

The goal of this study was the selection of a suitable suspending agent to prepare a stable oral suspension for drug delivery by ion-exchange resins. Suspending agents are used to increase the viscosity of the media to maintain uniform dispersion during storage. To select the best suspending agent، some formulations with different concentration of HEC، xanthan gum and HPMC were prepared and evaluated for physicochemical characteristics such as sedimentation volume and redispersibility. Prepared suspensions by HEC and HPMC as suspending agents in low concentrations had low sedimentation volumes and increasing in concentration caused to enhance in sedimentation volume but the redispersibility was difficult. The prepared suspensions using xanthan gum have good sedimentation volume and redispersibility. In suspensions prepared by HPMC and HEC، enhancement in concentration caused to increase in viscosity and to be difficult redispersibility that is in according to stock''s law which the more viscosity the lower sedimentation rate. Prepared formulation using xanthan gum contrast with low concentrations، in high concentrations had good sedimentation volumes and ease of redispersibility due to form a flocculating system.

The goal of the present study was the preparation and evaluation of griseofulvin topical gel as a drug dosage form with appropriate efficacy and stability. To select the best formulation, formulations with different concentration of carbomer and HPMC were evaluated for their appearance. Then evaluated for physicochemical characteristics such as rheologic behavior, viscosity, stability and drug release. The result showed that the topical gel of griseofulvin prepared with Carbomer 0.5% and HPMC2.5% had good chemical stability, viscosity and drug release. The evaluation of the kinetic of drug release indicated that the formulations containing Carbomer 0.5% and HPMC 2.5% followed zero order release and liner Wagner, respectively. Rheologic data showed that while HPMC gel shows a very mild plastic behavior, Carbomer based gels behave very significantly as a thixotrop pseudo plastic gel. Rheologic behavior can affect the physicochemical and pharmacological aspects of the drug and plastic behavior of carbomer gel made it suitable for topical application. Although clinical research is necessary for Confirm the effectiveness but as a result, topical griseofulvin in a suitable formulation showed good drug release and efficacy.