In vitro evaluation of acyclovir/chitosan floating systems



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Ruiz-Caro, Roberto and Veiga, María D. (2010) In vitro evaluation of acyclovir/chitosan floating systems. Materials, 3 (12). pp. 5195-5211. ISSN 1996-1944

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Chitosan (CS) floating lyophilized formulations (L) for gastric drug delivery of acyclovir (ACV) have been developed. The freeze-dried formulations were obtained from
acidic aqueous suspensions prepared with different ACV/CS ratios. No changes in ACV crystallinity were observed during X-ray diffraction powder studies as a consequence of the manufacturing process. Considering that fed and fasted states modified the intragastric pH, swelling and in vitro dissolution studies were carried out in different acidic media (0.1 M HCl and progressive pH medium) in order to understand the influence of these physiological states on ACV/CS formulations. Swelling behavior of the floating
lyophilized formulations was dependent on CS and ACV proportions within L and on medium nature due to pH dependent CS solubility. Furthermore, no interactions between ACV and CS were detected in solid state according to the X-ray studies. In vitro dissolution of ACV from L was influenced by the swelling behavior. However, it is
feasible to optimize the ACV/CS ratios to achieve a desired formulation that releases the total quantity of ACV at a specific time. Moreover, floatability was assessed by buoyancy tests. The results demonstrated that the freeze-drying process achieved effective floating systems capable of remaining within the stomach while the total amount of ACV is released from L.

Item Type:Article
Uncontrolled Keywords:Acyclovir, chitosan, floating freeze-dried formulations, swelling behavior controlled release
Subjects:Medical sciences > Pharmacy > Pharmacology
ID Code:68801
Deposited On:18 Nov 2021 10:01
Last Modified:20 Dec 2021 08:55

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