Comparison of the Particle Sizes of Different Steroids and the Effect of Dilution

Abstract

Commercial betamethasone is the recommended preparation if a nonsoluble steroid is preferred. Dexamethasone is a nonparticulate steroid, but its routine use awaits further studies on its safety and efficacy.

Eficacia analgésica de una dosis única de dexametasona perineural en el bloqueo ecoguiado del nervio femoral en cirugía de prótesis total de rodilla

“…Benzon et al 127 comparan el tamaño de las partículas de distintos corticoides y observan que la dexametasona fosfato de sodio (utilizada en nuestro estudio), es un corticoide líquido puro, exento de micropartículas, pudiendo ser por tanto, más segura y eficaz que el resto de corticoides empleados a nivel neural.…”

ASRA Practice Advisory on Neurologic Complications in Regional Anesthesia and Pain Medicine

“…61 In vitro studies note that methylprednisolone has the largest particles, betamethasone the smallest, and dexamethasone has no particulate matter. 64 While evidence of unintended injection into perispinal vessels during transforaminal injection has been reported, direct evidence to confirm or refute the role of particulate steroids in causing subsequent neuronal injury is lacking (Table 6). …”

Particulate versus non-particulate steroids for lumbar transforaminal or interlaminar epidural steroid injections: an update

“…Particulate steroids are available as lyophilisates provided in powder form needing reconstitution or as injectable suspensions, which contain solid particles sometimes in a mixture with a soluble corticosteroid. Most of the particles cover a size range between 0.5 and 100 μm, however sporadic particles even exceed a size of more than 1,000 μm [49]. The following corticosteroids belong to the group of particulate steroids: triamcinolone acetonide, methylprednisolone acetate, betamethasone acetate, and prednisolone acetate.…”

“…In contrast, dexamethasone sodium phosphate is considered as freely water-soluble. Thus, dexamethasone preparations are allocated to the non-particulate steroid group, despite the fact that some sporadic and small particles might be seen under the microscope with a typical particle size of 0.5 μm [31,49,50]. Betamethasone preparations are outliers of this binary classification: betamethasone preparations are commonly a mixture of betamethasone acetate (insoluble needing esterase activation) and betamethasone sodium phosphate (in solution) and provide characteristics of both groups, the particulate and nonparticulate steroids [31,49,50].…”

“…Thus, dexamethasone preparations are allocated to the non-particulate steroid group, despite the fact that some sporadic and small particles might be seen under the microscope with a typical particle size of 0.5 μm [31,49,50]. Betamethasone preparations are outliers of this binary classification: betamethasone preparations are commonly a mixture of betamethasone acetate (insoluble needing esterase activation) and betamethasone sodium phosphate (in solution) and provide characteristics of both groups, the particulate and nonparticulate steroids [31,49,50]. Moreover, there are also substantial differences in the propensity of different corticosteroid particles to aggregate into larger particles depending on the chemical ingredient (esters with larger particulate size), on the varying concentrations, on the drug vehicle, or on the drug mixtures with local anesthetics and/or contrast media prepared in-situ for pain treatment [50].…”