Quantitative determination of steroids in semi-solid pharmaceutical preparations by using high-performance liquid chromatography

Dilutions of corticosteroid creams and ointments — a stability study

A study was carried out on the stability of dilutions of creams and ointments of two corticosteroids, betamethasone valerate and beclomethasone dipropionate. A reversed-phase high-performance liquid chromatographic method was developed that is simple, efficient and stability-indicating in respect of the main decomposition products and has the advantage of being carried out at ambient temperature. The effect of water content of the sample solutions and the influence of large injection volumes (200-250 mul) on the resolution of the substances on the chromatogram was investigated. Use of the diluents, cetomacrogol cream (formula A) BP and white soft paraffin BP, resulted in satisfactory products in terms of chemical stability and efficacy of antimicrobial preservation.

Radiolytic degradation scheme for 60Co-irradiated corticosteroids

The cobalt 60 radiolytic degradation products have been identified in the following corticosteroids: cortisone, cortisone acetate, hydrocortisone, hydrocortisone acetate, hydrocortisone sodium succinate, isoflupredone acetate, methylprednisolone, methylprednisolone acetate, prednisolone, prednisolone acetate, and prednisone. Two major types of degradation processes have been identified: loss of the corticoid side chain on the D-ring to produce the C-17 ketone and conversion of the C-11 alcohol, if present, to the C-11 ketone. Minor degradation products derived from other changes affecting the side chain are also identified in several corticosteroids. These compounds are frequently associated in corticosteroids as process impurities or degradation compounds. No new radiolytic compounds unique to 60Co-irradiation have been found. The majority of corticosteroids have been shown to be stable to 60Co-irradiation. The rates of radiolytic degradation ranged from 0.2 to 1.4%/Mrad.

High-pressure liquid chromatographic determination of corticosteroids in topical pharmaceuticals

Cortisone, hydrocortisone, prednisolone, and prednisone were separated on a reversed-phase microparticulate high-pressure liquid chromatographic (HPLC) column with a ternary mobile solvent containing tetrahydrofuran, methanol, and water. Cortisone acetate, hydrocortisone acetate, and prednisolone acetate were separated on the same reversed-phase column using acetonitrile-water. Various commercial topical formulations of these corticosteroids, except cortisone and prednisone, were prepared by both simple dilution and by extraction for analysis by the proposed HPLC procedure, by the blue tetrazolium procedure, and by the isoniazid procedure and/or phenylhydrazine method. Retention data are given for some common degradation products (C-17 ketones and C-17 carboxylic acid derivatives) and for methyl-, propyl-, and butylparabens with these mobile solvents.