Isoniazid Proliposome Powders for Inhalation—Preparation, Characterization and Cell Culture Studies

Wipaporn Rojanarat,Sirirat Pinsuwan,Ekawat Tawithong,Teerapol Srichana,Narumon Changsan,Hak-Kim Chan

doi:10.3390/ijms12074414

Isoniazid Proliposome Powders for Inhalation—Preparation, Characterization and Cell Culture Studies

Wipaporn Rojanarat, Sirirat Pinsuwan + Show 4 more

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https://doi.org/10.3390/ijms12074414

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Abstract

The aims of this study were to develop proliposome powders containing isoniazid (INH) in a dry powder aerosol form. INH-proliposome powders were prepared by a spray drying method. Proliposome physicochemical properties were determined using cascade impactor, X-ray diffraction and differential scanning calorimetry. The toxicity of proliposomes to respiratory-associated cell lines and its potential to provoke immunological responses from alveolar macrophages (AM) were determined. Free INH and INH-proliposome bioactivities were tested in vitro and in AM infected with Mycobacterium bovis (M. bovis). Aerosolization properties of INH-proliposome powders at 60 L/min, the powders showed mass median aerodynamic diameters of 2.99–4.92 μm, with fine particle fractions (aerosolized particles less than 4.4 μm) of 15–35%. Encapsulation of INH was 18–30%. Proliposome formulations containing INH to mannitol ratios of 4:6 and 6:4 exhibited the greatest overlapping peak between the drug and mannitol. INH-proliposomes were evidently nontoxic to respiratory-associated cells, and did not activate AM to produce inflammatory mediators—including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and nitric oxide—at a toxic level. The efficacy of INH-proliposome against AM infected with M. bovis was significantly higher than that of free INH (p < 0.05). INH-proliposomes are potential candidates for an alternative tuberculosis treatment.

Highlights

Isoniazid (INH), a first-line hydrophilic antituberculosis agent, is difficult to encapsulate in liposomes which is increasingly used and the results have been very promising [1,2,3]
Mannitol has been previously evaluated as a potential drug carrier in dry powder inhaler formulations [13]
At day 7 there were no viable cells when M. bovis was challenged with all concentrations of INH and INH-proliposome. These results demonstrated that INH and INH-proliposomes were able to kill the bacilli by the third day of incubation, and were even more effective on day 7

Summary

Introduction

Isoniazid (INH), a first-line hydrophilic antituberculosis agent, is difficult to encapsulate in liposomes which is increasingly used and the results have been very promising [1,2,3]. Liposomes in aqueous systems suffer from physical instability due to hydrolysis or oxidation, resulting in the loss of the encapsulated active component from the liposome. This is especially a problem in the case of hydrophilic agents. Proliposome, a dry free-flowing powder, can be hydrated immediately to form liposomes through contact with water or biological fluids [5]. The purpose of this attempt is to overcome the problems associated with aqueous liposome dispersion. The microporous structure of the carrier materials maintains the free flow of the powder. The manufacturing procedures appear to be tedious and difficult to control, since the operation requires: (a) a discontinuous step of solvent addition and evaporation; (b) close monitoring to ensure that the powder is not allowed to become overly wet, and the unit is operated under a vacuum; and (c) overnight drying of the proliposome in a desiccator under reduced pressure [8]

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