¹Department of Pharmaceutics, College of Pharmacy, Mustansiriyah University, Baghdad, Iraq DOI : 10.29228/jrp.2022.00 This study used dumping and transfer methods to examine the dissolution of a poorly water-soluble weak base, the ciprofloxacin HCl (Cipro). The objective is to investigate the impact of pH variations from the stomach to the intestine on drug dissolution and precipitation (ppt). Three strategies were utilized to enhance the solubility and reduce the ppt of Cipro. First, it employed the acid modification concept, combining Cipro with fumaric acids (FA). The second was solvent evaporation, which transformed the medication from crystalline to amorphous. Third, the gastroretntive dosage form releases the drug slowly and remains buoyant. The produced samples were examined using FTIR, FESEM, and DSC. The FESEM showed a decrease in particle sizes of prepared samples. The FTIR presented a change in the position of the peak associated with the carbonyl group from 1712 cm-1 to 1704 cm-1 in the Cipro-FA complex and a peak shift to 1730 cm-1 of Cipro when treated by solvent evaporation. Additionally, the thermogram of the Cipro-FA complex demonstrated a clear shift of peaks to 148.73 °C and 240.47 °C, revealing possible hydrogen bonding. The thermogram of Cipro by solvent evaporation presented a disappearance of the peak at 162.44 ℃. The Cipro in vitro dissolution studies on the prepared samples revealed distinct differences in the dissolution profiles between dumping and the most mimicking body transfer method. To conclude, the samples exhibited improved dissolution profiles and a reduced ppt amount; specifically, the complexation of Cipro –FA was the optimal strategy for enhancing solubility and dissolution while reducing ppt. Keywords : Ciprofloxacin; floating system ; fumaric acids; gastroretentive dosage form; solvent evaporation