Measurement of particle and mass distribution of pentamidine aerosol by ultrasonic and air jet nebulizers.
The use of appropriate nebulizers is a major precondition for a successful treatment and prevention of Pneumocystis carinii pneumonia with pentamidine aerosol.  The apparatus should supply a sufficient amount of pentamidine with adequate particle size.  Using Fisons ultrasonic nebulizer FISO Neb, model FZV 40 BAMKI, De Vilbiss ultrasonic nebulizer, Porta-Sonic, model 8500 GB, and the Marquest Medical Products jet nebulizer Respirgard II, two pentamidine concentrations (300 mg/6 ml and 60 mg/6 ml) were compared by measuring nebulized pentamidine mass distribution and particle size distribution under in vitro conditions by means of a laser light-scattering particle sizer of the type Malvern Master sizer.  It was found that there were significant differences among nebulizers.  Mass distribution experiments with air flow 6 l/min showed that using FISO Neb the quantity of nebulized pentamidine was 201.4 mg and 36.7 mg, whereas using Porta-Sonic the values found decreased to 85.2 mg and 23.6 mg.  Using Respirgard II the values were 80.0 mg and 10.64 mg.  The measured total duration times of nebulization were 6 - 8.5 min, 12 min and 25 min for the nebulizers FISO Neb, Porta-Sonic and Respirgard II.  A decomposition of pentamidine during nebulization in the case of ultrasonic nebulizers doesn't take place. The measured mass median diameters (MMD) were 5.6 - 6.9 mum, 1.96 - 3.04 mum and 1.9 - 2.5 mum for the nebulizers FISO Neb, Porta-Sonic and Respirgard II.  Using 300 mg pentamidine the nebulized amounts of pentamidine containing particles sizes less than or equal to 2 mum predominately available for alveolar deposition were with values of about 43 mg markedly higher for Respirgard II and Porta-Sonic than the measured 10.5 mg for FISO Neb.
Rhône-Poulenc Rorer GmbH, Köln.
J
J
Hager
K H
KH
Gober
J P
JP
Löhr
M
M
Dürr
D000336:Aerosols; D004355:Drug Stability; D006801:Humans; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D010419:Pentamidine / Q000008:administration & dosage* / Q000737:chemistry; D011020:Pneumonia, Pneumocystis / Q000188:drug therapy*; D014465:Ultrasonics