Operating Characteristics of 18 Different Continuous-Fiow Jet Nebulizers With Beclomethasone Dipropionate Liposome Aerosol – Results

Operating Characteristics of 18 Different Continuous-Fiow Jet Nebulizers With Beclomethasone Dipropionate Liposome Aerosol - ResultsA computer model originally developed by Persons et al was modified according to MMAD and GSD and used to calculate regional deposition of the 18 aerosols. The human lung model was based on the following parameters: mouth breathing, functional residual volume 3,300 ml, tidal volume 750 ml, inspiration 2 s, expiration 2 s, no pause. Regional deposition was calculated for mouth and pharynx, conducting airways (Weibel model generations 0 to 16), and alveolated airways (Weibel model generations 17 to 23). The aqueous suspension of Вес-DLPC liposomes approximated 0.5N (0.0045 g/ml) saline solution. Body weight was assumed to be 62.5 kg for calculation of dosage. The computer model results demonstrated good correlation with experimental regional deposition data from several investigators. buy asthma inhalers

The properties of the Вес-DLPC liposome aerosols produced by 18 nebulizers are shown in Tables 1 and 2. Nebulizers were ranked according to increasing MMAD of the particles, ranging from 0.9 to 7.2 [im. Table 2 also shows each corresponding GSD and the calculated regional deposition percentage of each aerosol predicted by the computer model for the mouth, generations 0 to 16 and 17 to 23 of human respiratory tract, as well as the total deposition. There is increased Bec-DP deposition in the mouth as the MMAD increases to 2.1 |im and higher. Increases in GSD also influence the predicted deposition patterns, particularly in the mouth and generations 0 to 16. Figure 1 is a graphic presentation from Table 2 to show the relative values of MMAD and corresponding GSD of the particles generated. The MMAD increases in fairly regular increments (from 0.9 to 7.2 |im) except for nebulizer No. 18 for which the MMAD was radically greater than the others. The GSD rises gradually from 1.8 to 2.8 with increasing MMAD.
From the amount of Bec-DP recovered in 2.5 min from the Andersen sampler, the percentage of deposition for the mouth and Weibel’s generations 0 to 23 can be utilized to calculate the predicted Bec-DP levels deposited in each region. Figure 2 demonstrates the predicted percentage of regional deposition of the 18 nebulizers. All nebulizers produced fairly uniform values for deposition within generations 17 to 23 with a mean value of 17.7 ± 1.9 percent. Deposition in the mouth and generations 0 to 16 increases gradually with increasing MMAD and GSD, except for the large increase with nebulizer No. 18.
Based on the amounts of Bee deposited within the Andersen sampler shown in Table 2, the estimated drug deposition at each regional area is shown in Figure 3. These data show greater variability among nebulizers than the percentage of deposition measurements since there is a wide range of total Bee output. Thus, while MMAD and GSD are major determinants of the site of deposition of aerosol particles within the respiratory track, the amount of drug delivered is a major feature of the nebulizer design and operation. Based on these analyses, nebulizers 3 to 12 show the greatest calculated deposition of Bec-DP in the alveolar region with the least calculated deposition in the mouth. The results of this study thus indicate that there is a wide range of operating characteristics among both nebulizer types and individual devices. Use of data such as presented herein will assist in selection of nebulizers best suited to a particular medical purpose.

Table 2—Characteristics qfBec-DLPC liposome Aerosol Produced by 18 Different Nebulizers

No. Nebulizer MMADltm±SD GSD±SD % Deposition Bee, fig Recovery 2.5 mint ± SD No.ofTests
% Mouth and Throat % Generations 0-16t % Generations 17-23t % Total
1 Rgrd 0.9 ±0.1 1.9±0.2 0.2 1.9 12.0 14.1 141 ±37 3
2 SPAG 1.3±0.3 1.8±0.1 0.6 3.0 14.9 18.5 90 ±10 3
3 Rd 1.3±0.1 2.5±0.2 3.0 4.6 16.1 23.7 243 ±63 3
4 Fan 1.5±0.2 2.6 ±0.3 4.0 5.4 16.7 26.1 225 ±95 3
5 3040 1.6 ±0.5 2.5 ±0.3 4.2 5.7 17.0 26.9 294 ±74 4
6 SJ 1.6±0.2 2.2±0.2 2.8 4.9 17.3 25.0 147 ±19 13
7 Nb Mist 1.7±0.3 2.1 ±0.5 3.0 5.3 18.0 26.3 187 ±17 3
8 Pw Mst 1.7±0.1 2.4±0.3 4.9 6.2 17.8 28.9 195 ±56 3
9 Acrn 1.8±0.4 2.5±0.4 5.3 6.5 18.0 29.8 219 ±114 4
10 H-Hld 2.0 ±0.2 2.0±0.2 3.6 6.1 19.6 29.3 143 ±21 3
11 Spira 2.0 ±0.6 2.1 ±0.3 4.3 6.4 19.4 30.1 190 ±29 3
12 Ava Nb 2.1 ±0.4 2.5 ±0.5 7.3 7.8 18.5 33.6 272 ±75 3
13 A-Twr 2.1±0.5 2.6±0.6 7.9 8.1 18.5 34.5 80±36 3
14 Pm Nb 2.2 ±0.6 2.5 ±0.4 7.6 8.1 18.9 34.6 171 ±54 4
15 Cm Nb 2.3±0.3 2.3 ±0.3 7.4 8.1 19.6 35.1 148 ±26 3
16 Wpjt 2.4 ±0.4 2.8 ±0.5 10.7 9.3 18.2 38.2 295 ±40 3
17 Up Mst 2.7±0.6 2.8 ±0.5 12.1 10.2 18.5 40.8 172 ±11 3
18 Heart 7.2±0.7 4.7±1.8 34.2 17.5 20.0 71.7 239 ±22 3

Figure-1

Figure 1. Mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) of 18 commercially available jet nebulizers with Bec-DLPC. Plotted points are connected for visual clarity.

Figure-2

Figure 2. Calculated percent deposition of beclomethasone dipro-pionate-diburoyl phosphatidylcholine (Вес-DLPC) liposome aerosol in mouth and throat, Weibel generations 0 to 16, and 17 to 23 for 18 nebulizers. Plotted points are connected for visual clarity.

Figure-3

Figure 3. Calculated beclomethasone dipropionate (Bec-DP) (p.g/ 2.5 min) deposited in mouth and throat, Weibel generations 0 to 16, and 17 to 23 for 18 nebulizers. Plotted points are connected for visual clarity.

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