A New Apparatus for the Determination of the Emitted Dose from Pressurized Metered Dose Inhalation Aerosols with Inhalation Devices

1995 ◽  
Vol 21 (12) ◽  
pp. 1399-1409 ◽  
Author(s):  
N. Gaddipati ◽  
M. Graziosi ◽  
M. Ganesad
Author(s):  
Ricardo F. Oliveira ◽  
Manuel V. Silva ◽  
Ana V. Machado ◽  
Manuel Oliveira ◽  
Helena Maria Cabral-Marques ◽  
...  

Due to the increasing worldwide incidence of asthma, a growing usage of inhalation devices has been observed. Some of the pressurized Metered Dose Inhalers (pMDI) limitations have been overcome by the introduction of newly and improved Valved Holding Chambers (VHC), resulting in good patient acceptance. The efficiency is assessed by the VHC Emitted Dose (ED), i.e. the amount of drug available to the patient. Using the pMDI salbutamol sulfate formulation (Ventolin® HFA-134a) as the test drug, several VHC devices were assessed. These latest were grouped by material characteristics: dissipative (OptiChamber Diamond®, AeroChamber Plus®, Vortex®, A2A Spacer®), non-dissipative (SpaceChamber Plus®, Compact SpaceChamber Plus®, Volumatic®) and stainless steel (Nebuchamber®). The pMDI + VHC were assembled to a filter housing, which comprises an induction port with similar USP Throat dimensions, and connected to a vacuum pump (calibrated at 15, 26 and 40 L/min). Using UV-Vis Spectrophotometry equipment at 244 nm, it was possible to determine its concentration for later mass calculation. For all the VHC devices tested, the total mass recovery percentage was between 85% and 120%. At 26 L/min, the Vortex® VHC has shown the highest ED (47.3 ± 1.8 %). The ED may not be dependent on the volume of the VHC. Although, further analysis of the results suggests the existence of a linear correlation between the ED and the VHC body length. SpaceChamber Plus® results show an increase of the ED and, subsequently, a decrease in VHC deposition fraction, with the increase of airflow.


In a previous communication from these laboratories by G. A. Scott an account was given of the determination of the isotherms of hydrogen, carbon monoxide and mixtures of the two in the molecular proportion 2 : 1, 1 : 1 and 1 : 2 over a pressure range up to 170 atmospheres and at a temperature of 25° C. Since the completion of that investigation new apparatus has been installed so that the pressure and temperature ranges might be extended; and in this paper are embodied the results of further determinations carried out at both 0° C. and 25° C. and over a pressure range extending up to 600 atmospheres. In pursuing this investigation further it is our endeavour to furnish information in regard to the gaseous mixtures in question over the pressure and temperature ranges now commonly used in industrial processes. The Isotherms of the Single Gases . A repetition in our new apparatus of the determinations previously made by Scott both for the single gases and gas mixtures at 25° C. and at pressures up to 170 atmospheres showed his figures to be in close agreement with our own, the variations never exceeding 0·1 per cent.


Author(s):  
Elena Bezuglaya ◽  
Nikolay Lyapunov ◽  
Vladimir Bovtenko ◽  
Igor Zinchenko ◽  
Yurij Stolper

Aim. The purpose was to provide the rationale of test in regard to uniformity of fine particles dose for pressurised metered dose inhalers (pMDIs). Materials and methods. The pMDIs containing suspensions of salbutamol sulfate (SS) or solutions of beclometasone dipropionate (BD) were studied by laser diffraction and high performance liquid chromatography (HPLC). The particle size distribution of SS, the average dose mass and uniformity of dose mass, the average delivered dose and the uniformity of delivered dose, the average fine particles dose and uniformity of fine particles dose were determined. Apparatus A was used for assessment of fine particles dose. Results. The two analytical procedures for the quantitative determination of SS and BD by HPLC were validated in the ranges with low concentrations of these substances. The 5 medicinal products in pMDI dosage form were studied: 3 preparations were with SS and 2 ones contained BD. It was shown that three products with SS were very similar in regard to particle size distribution in containers and the average values of delivered dose were almost the same, but these products were different in the average dose mass and fine particle dose. According to the research results, the expediency of determining the average dose mass and the tests concerning uniformity of dosing of preparations by dose mass and by fine particle dose was substantiated. It was shown that in the case of pMDI the dosing of solutions of BD was more uniform compared to suspensions of SS. The approaches of leading and other pharmacopoeias concerning uniformity of dosing for pMDIs were critically discussed. The expediency of determination of uniformity of fine particle dose at the stage of pharmaceutical development was substantiated, as the therapeutic effect depends on fine particle dose. Issues concerning standardization pMDIs in regard to uniformity of fine particle dose were discussed. Conclusions. The expediency of standardization and quality control of pMDIs in regard to such attributes as the average dose mass, which characterizes the volume of the metering chamber of the valve as well as the uniformity of the dose mass and the uniformity of fine particle dose, which assure the therapeutic effect of each dose of the product was substantiated


2021 ◽  
Vol 33 (11) ◽  
pp. 2723-2728
Author(s):  
Surya Prakash Mamillapalli ◽  
Gourabattina Lakshmi Prasanna ◽  
B. Venkata Subbaiah ◽  
N. Annapurna

Stability indicating reversed phase-HPLC method for simultaneous estimation of mometasone furoate (MAF) and formoterol fumarate (FFD) in metered dose inhalation aerosol (MDI) dosage formulation has been developed and discussed in the present work. The chromatographic separation was achieved using Hypersil ODS column (250 mm × 4.6 mm, 3 μm) using an isocratic separation mode at a flow rate of 1.2 mL/min, column temperature of 50 ºC. The system operates with a mobile phase comprising of solution-A (buffer): Solution-B (acetonitrile) mixed in the ratio of 70:30 %v/v at a UV detection wavelength of 214 nm. Retention times of mometasone furoate and formoterol fumarate found to be about 3 min and 7 min, respectively. All possible degradation products of both compounds were monitored at 214 nm and spectral purity along with % mass balance is assessed using PDA detector. Both analyte were subjected to force degradation studies, found all degradants were resolved from analyte peaks and also other process-related impurities. The proposed method is validated for specificity, linearity, accuracy, precision and robustness as per ICH guidelines and found to be adequate. Method stood to be robust with variation in column temperature, flow rate, pH of buffer and organic content in mobile phase.


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