Logical formulation development for Furosemide dissolution enhancement by preparing solid dispersion containing adsorbent


By Rajanikant C. Patel, Natvarlal M. Patel, Madhabhai M. Patel


Furosemide, a weekly acidic, loop diuretic drug indicated for treatment of edema and hypertension having high permeability through stomach because it remain 99.8 % unionize in stomach (pKa of Furosemide 3.9, pH of gastric fluid-1.2). Furosemide is practically insoluble in stomach medium (0.006 mg/mL) and having highly permeability through stomach but due to its solubility limitation it can’t enter in to systemic circulation. Gastric empting time is ranging from 30 min to 2 hrs after this time it goes in to small intestine where it is soluble but can’t permeate through its membrane due to its permeation limitation (furosemide having pH depended solubility and permeability). Furosemide available in dose of 20 mg, 40 mg and 80 mg tablets. In present work, 40 mg furosemide was taken. Solubility depends on amount of solute, amount of solvent, temperature, stirring speed, time and other factors. Due to low dose of drug it can be dissolves within gastric empting time if solubility enhancing excipients added. It was logically decided to design experiments, so as to achieve the set objectives. Thus, an attempt was made to prepare solid dispersion of furosemide with Poly ethylene glycol (PEG) 6000 containing microcrystalline cellulose (MCC) as adsorbent which would dissolve completely in less than 30 minutes (target selected by considering minimum gastric empting time). These attempts improve bioavailability and consequently dose reduction would possible.

Key Words : Furosemide, PEG 6000, solid dispersion, Micro crystalline cellulose, dissolution.

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