INFLUENCE OF MELTING-POINT AND HYDROPHILIC LIPOPHILIC BALANCE ON THE RELEASE OF SALBUTAMOL SULFATE FROM LIPID MATRICES/

Salbutamol is a drug with a short elimination half life, and is thus a possible candidate for the development of sustained release formulati ons. We developed sustained release lipid matrices using Gelucires. Th ree different release profiles were observed : fast release, in the ca se of Gelucires 33/01, 35/10, 37/02, 42/12 and 44/14, with a mean diss olution time (Td(50)) of 6, 16, 3, 40 and 12 min; a sustained release for Gelucires 48/09, 50/13 and 53/10 with a mean dissolution time of 1 86, 147 and 168 min; and a slow release for Gelucires 46/07 and 50/02, with a mean dissolution time of 310 and 621 min, respectively. The pe rcentages of salbutamol released with Gelucires 46/07 and 50/02 were b elow 60% of the dose. Multiple regression analysis of the hydrophilic/ lipophilic balance (HLB), melting point (MP), dissolution constant (K- 1) and mean dissolution time (Td(50)) yielded the following equations: K-1 = 3.13 - 0.262HLB - 0.0648*MP + 0.00556 HLB*MP, (R(2) = 0.88), a nd Td(50) = - 1485 + 105HLB + 43.2*MP - 3.03 HLB*MP, (R(2) = 0.91).