الفهرس 
General introductionOnly 14 pages are availabe for public view
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Abstract
Baclofen is a centrally acting skeletal muscle relaxant. Unfortunately; baclofen is associated with significant and frequent side effects, these side effects include; dizziness, drowsiness, confusion, insomnia, nausea, and orthostatic hypotension. This thesis was concerned with the design and characterization of modified release baclofen floating systems. preformulation studies including fundamental physical properties of baclofen such as UV-spectrophotometric assay, high performance liquid chromatography (HPLC), drug-excipient interactions, partition coefficient, permeation studies, and forced degradation studies. Results showed that first derivative (D1) spectrophotometric assay which is more sensitive than the D0 one. Also; baclofen is compatible with various excipients used in the formulation of gastroretentive dosage forms. In addition, baclofen was found to be chemically stable under various stress conditions such as acidic, alkaline, and thermal conditions. There is also some evidence that baclofen absorption may take place via a special transport mechanism through the gut wall.
Modified release baclofen floating granules and beads were prepared. The prepared granules and beads showed floating properties up to 24 h with a different floating lag time ranging from zero to 72.33 sec, which could indicate well accepted floating characteristics. Most of the formulation significantly extended baclofen release for up to 8 h compared to 0.2 h with the marketed baclofen tablets. Surface coating of beads with either Eudragit RS 100 or Eudragit L 100 modified release of baclofen from the beads. Beads coated with cetyl alcohol as wax forming agent failed to modify baclofen release due to the weak electrostatic binding forces with the prepared beads. This formulation did not exhibit any change in the morphology, drug content, or release profile upon storage for up to 12 months. Animal studies showed modified release baclofen floating formulations have the ability to decrease burst effect associated with commercial immediate release baclofen tablets, in addition to sustain baclofen release for more than 6 h. this effect was confirmed by measuring Cmax, Tmax, and AUC0-24. Results also confirmed that modified release baclofen floating formulations didn’t significantly affect the blood pressure unlike commercial immediate release tablet which decreases blood pressure.