Budesonide-loaded guar gum microspheres for colon delivery: preparation, characterization and in vitro/in vivo evaluation

A novel budesonide (BUD) colon delivery release system was developed by using a natural polysaccharide, guar gum. The rigidity of the microspheres was induced by a chemical cross-linking method utilizing glutaraldehyde as the cross-linker. The mean particle size of the microspheres prepared was found to be 15.21 ± 1.32 µm. The drug loading and entrapment efficiency of the formulation were 17.78% ± 2.31% and 81.6% ± 5.42%, respectively. The microspheres were spherical in shape with a smooth surface, and the size was uniform. The in vitro release profiles indicated that the release of BUD from the microspheres exhibited a sustained release behavior. The model that fitted best for BUD released from the microspheres was the Higuchi kinetic model with a correlation coefficient r = 0.9993. A similar phenomenon was also observed in a pharmacokinetic study. The prolongation of the half-life (t_1/2), enhanced residence time (mean residence time, MRT) and decreased total clearance (CL) indicated that BUD microspheres could prolong the acting time of BUD in vivo. In addition, BUD guar gum microspheres are thought to have the potential to maintain BUD concentration within target ranges for a long time, decreasing the side effects caused by concentration fluctuation, ensuring the efficiency of treatment and improving patient compliance by reducing dosing frequency. None of the severe signs, like the appearance of epithelial necrosis and the sloughing of epithelial cells, were detected.

Physicochemical compatibility of nebulizable drug admixtures containing budesonide and colistimethate or hypertonic saline

Knowledge of the physicochemical compatibility of admixtures of nebulizable drugs is an important issue. In this article, the results of our recent study dealing with the compatibility of drug admixtures containing budesonide and colistin methanesulfonate (brand name Colistin CF) or budesonide and 5.85% sodium chloride solution are presented, as well as the up-to-date version of our compatibility table. Admixtures were prepared by mixing 2.0 mL Pulmicort either with 3.0 mL Colistin CF or 4.0 mL 5.85% sodium chloride solution. Test solutions were stored for 24 hours at room temperature under ambient light conditions. Physical compatibility was determined by measuring pH and osmolality. Concentrations of budesonide were measured by a high-performance liquid chromatography assay. The antibiotic activity of colistin methanesulfonate was determined in comparison to standard solutions using a microbiological assay. No loss in drug concentration of budesonide and no change in antibiotic activity of colistin methanesulfonate were detected over a test period of 24 hours. Osmolality remained unchanged in both types of admixtures. In admixtures of budesonide with colistin methanesulfonate, pH increased during the first 4 hours of storage, while in admixtures of budesonide and hypertonic saline pH remained unchanged. No visible changes could be detected. Due to these results admixtures of budesonide and colistin methanesulfonate or 5.85% sodium chloride solution are designated to be compatible, but it is recommended that mixing should take place immediately before administration. Further investigations are needed to determine whether or not drug delivery is affected by mixing the drugs and to ensure simultaneous nebulization is recommendable.

Development and validation of a stability-indicating high-performance liquid chromatography method for the simultaneous determination of albuterol, budesonide, and ipratropium bromide in compounded nebulizer solutions

In recent years, there has been a large increase in the use of pharmaceutical compounding to prepare medications that are not commercially available. The treatment of asthma typically includes the use of albuterol (ALB), ipratropium bromide (IPB), and/or budesonide (BUD) nebulizer solutions. There is currently no commercially available nebulizer solution containing all three of these compounds, and patients must rely on often-unregulated compounding. There is a distinct need for methodologies that can be used to analyze compounded formulations to ensure patient safety. We report an HPLC-UV method to separate and quantitate ALB, IPB, and BUD in nebulizer solutions. The method used a gradient elution to achieve separation via an RP C18 column. The method was validated, showed good selectivity, and was linear over several orders of magnitude. The method was applied to the analysis of nebulizer solutions and determination of their storage stability. Significant ALB-dependent degradation occurred within 5 h in solutions formulated with the free base of ALB, while those containing the sulfate salt of ALB produced no degradation. Alkali solutions can cause base-catalyzed hydrolysis of IPB and degradation of BUD. Compounded formulations containing ALB need to include an acid to control pH and prevent degradation.

Development, Evaluation and Data Acquired with a Tape-Stripping Technique for Measuring Dermal Exposure to Budesonide at a Pharmaceutical Manufacturing Site

OBJECTIVES

Although corticosteroids have been used for over 50 years as anti-inflammatory and anti-proliferative agents, few studies have examined their exposure levels and health effects on workers employed in the corticosteroid manufacturing industry. The aims of the study reported here were to develop a tape-stripping technique for monitoring budesonide (a corticosteroid used in inhalators for treating respiratory diseases) and to apply the method in a pilot study to estimate the potential dermal exposure to budesonide among workers at a pharmaceutical formulation site.

METHODS

The tape-stripping method was evaluated by applying 0.5 and 2.07 microg of budesonide dissolved in ethanol on tape strips. The same amounts were also applied on a cleaned glass plate and human skin of volunteers, which were then stripped by series of tapes immediately, and 30 min later, the amounts collected by the tapes were measured. Finally, the technique was used to study the exposure of budesonide among eight employees at a pharmaceutical industry site. Three exposure sites were tested: the tip of the forefinger, palm of the hand and ventral part of the lower arm. Five consecutive tape strips per sampling site were used in both the recovery studies and the field study.

RESULTS

The mean overall recoveries from spiked tapes and the glass plate were 96 and 81%, respectively, while for human skin the corresponding figure was 38%, (for applications of 2.07 microg; no detectable amounts were recovered from human skin after 0.5 microg applications). The recovered amount was found on two consecutive tapes after 0 min, but only on the first tape strip after 30 min. The inter-individual variability was 4-fold. In the field, quantifiable amounts were found for four of eight employees and a concentration gradient was detected along the two or three consecutive tape strips. The tip of the forefinger and the palm of the hand were the most highly exposed sites to budesonide.

CONCLUSIONS

A tape-stripping method can be used to determine potential dermal exposure to budesonide. The results also indicate that budesonide is taken up by the skin of operators who are exposed to the substance at their workplace.

High performance liquid chromatography assay method for simultaneous quantitation of formoterol and budesonide in Symbicort Turbuhaler

A sensitive and rapid high performance liquid chromatography method has been developed and used for the simultaneous determination of formoterol and budesonide in Symbicort Turbuhaler when assessing the aerodynamic characteristics of the emitted dose using Pharmacopoeial methods. This capability results in both time and cost saving. The mobile phase composition was acetonitrile-5 mM sodium dihydrogen orthophosphate, pH 3 (60: 40% v/v), and was passed at 1.5 ml min(-1) through a C18 column with a UV detection (wavelength 214 nm). The method was shown to give good analytical performance in terms of linearity, precision (using phenylpropanolamine as an internal standard), sensitivity and solution stability. The intra-day precision for both formoterol and budesonide were 0.75% and 1.11%, respectively (n = 10). The limit of quantitation for formoterol was 10 microgL(-1) and for budesonide was 120 microgL(-1), and the limit of detection were 3 and 30 microgL(-1), for both formoterol and budesonide, respectively. The method has been applied to determine the content of the emitted dose and the fine particle dose of Symbicort Turbuhaler.

Development and validation of a high-performance liquid chromatographic method for the analysis of budesonide

A simple, rapid, and stability indicating reversed-phase high-performance liquid chromatography (HPLC) method of analysis for budesonide, a novel glucocorticoid prescribed for inflammatory bowel disease, was successfully developed. Budesonide is an epimeric mixture and both the epimers have similar anti-inflammatory activity. All the analytical methods reported in the literature are long and are based on separation of the epimers, thus our objective was to obtain a single sharp peak of the drug and to separate the drug peak from all the other degradation products. The method, was used to quantify budesonide in the developed formulation, employed a Kromasil C8, (150 mm x 4.6 mm) column with an isocratic mobile phase of acetonitrile-phosphate buffer (pH 3.2-0.025 M) (55:45 v/v), at a flow rate of 1.1 mL/min. Budesonide was detected by an ultraviolet detector at 244 nm. The method was validated for linearity, precision, repeatability, sensitivity, and selectivity. Selectivity was validated by subjecting stock solution of budesonide to acidic, basic, oxidative, and thermal degradation. The retention time of budesonide was about 4 min with symmetrical peaks. The method was linear over a concentration range 1-50 microg/mL (R2=0.9995). The limit of detection of budesonide was 0.1 microg/mL and the limit of quantitation was 0.25 microg/mL. The peaks of the degradation products did not interfere with the peak of budesonide. The developed method was used to quantify budesonide in budesonide-loaded micro-particles. Excipients present in the micro-particles did not interfere with the analysis and the recovery of budesonide from micro-particles was quantitative.

Chromatographic and mass spectral characterization of budesonide and a series of structurally related corticosteroids using LC–MS

The LC-MS characteristics of budesonide and a series of structurally related corticosteroids were reviewed to commence the construction of a library of chromatographic and mass spectral information to aid identification of budesonide degradation products during formulation stabilization investigations. The LC-ESI(+)-MS technique employing a Hypersil C18 column with a mobile phase of ethanol-acetonitrile-formic acid (pH 3.8; 0.14 mM) (2:30:68, v/v/v) was then used to characterize 23 corticosteroids. Based on their structures, the corticosteroids were classified into three groups: (I) 4-pregnene-3-one steroids; (II) 1,4-pregnadien-3-one steroids with no fluorine substituents; and (III) 1,4-pregnadiene-3-one steroids with fluorine substituents. Chromatographic (retention time and UV absorbance) and mass spectral properties were correlated with the known chemical structures of these corticosteroids. Base peak and mass spectral fragmentation patterns were related to steroid structural characteristics.

Surface Energy and Interparticle Force Correlation in Model pMDI Formulations

PURPOSE

To compare experimental measurements of particle cohesion and adhesion forces in a model propellant with theoretical measurements of the interfacial free energy of particulate interactions; with the aim of characterizing suspension stability of pressurized metered dose inhalers (pMDIs).

METHODS

Interparticulate forces of salbutamol sulfate, budesonide, and formoterol fumarate dihydrate were investigated by in situ atomic force microscopy (AFM) in a model propellant 2H,3H perfluoropentane. The surface thermodynamic properties were determined by contact angle (CA) and inverse gas chromatography (IGC). Experimental data were compared with theoretical work of adhesion/cohesion using a surface component approach (SCA), taking into account both dispersive and polar contributions of the surface free energy.

RESULTS

Results indicated that the measured forces of interaction between particles in model propellant could not be accounted for by theoretical treatment of the dispersive surface free energies via CA and IGC. A correlation between theoretical work of adhesion/cohesion and AFM measurements was observed upon the introduction of the polar interfacial interactions within the SCA model.

CONCLUSIONS

It is suggested that the polar contributions of the surface free energy measurements of particles may play a crucial role in particle interaction within propellant-based systems. Together with the application of a SCA model, this approach may be capable of predicting suspension stability of pMDI formulations.

Lower oropharyngeal deposition of inhaled ciclesonide via hydrofluoroalkane metered-dose inhaler compared with budesonide via chlorofluorocarbon metered-dose inhaler in healthy subjects

OBJECTIVE

Inhaled corticosteroids may cause oropharyngeal side effects if deposited in the oropharynx in active form. Ciclesonide, an inhaled corticosteroid with low glucocorticoid receptor affinity, is activated primarily in the lung by esterases to an active metabolite, desisobutyryl-ciclesonide (des-CIC), with high glucocorticoid receptor affinity. We studied oropharyngeal deposition of ciclesonide, des-CIC, and budesonide.

METHODS

In an open-label, randomized, two-treatment (administered in sequence), five-period study, 18 healthy subjects received 800 microg (ex-valve) inhaled ciclesonide via a hydrofluoroalkane-pressurized, metered-dose inhaler followed by 800 microg budesonide (Pulmicort) by a chlorofluorocarbon-pressurized, metered-dose inhaler (four puffs of 200 microg each, ex-valve) or vice versa. Oropharyngeal cavity rinsing was performed immediately, or 15, 30, 45, or 60 min after inhalation (one rinsing per study period), and the solutions were analyzed using liquid chromatography with tandem mass spectrometric detection.

RESULTS

Ciclesonide and budesonide were detected in most oropharyngeal wash samples. Maximal concentration of each inhaled corticosteroid was reached immediately post-inhalation; maximal concentrations of ciclesonide and des-CIC were 30% and 0.67%, respectively, of budesonide. Oropharyngeal deposition of ciclesonide and budesonide decreased rapidly within 15 min post-inhalation, and less rapidly thereafter. Less than 10% of the residual ciclesonide in the oropharynx was converted to des-CIC. The molar dose-adjusted amount of des-CIC was 4% of budesonide (P < 0.0001). There were no significant adverse events.

CONCLUSION

Oropharyngeal deposition of des-CIC was more than one order of magnitude lower than that of budesonide when administered by the respective metered-dose inhalers. This may explain the low frequency of oropharyngeal side effects of ciclesonide in clinical studies.

Direct separation, identification and quantification of epimers 22R and 22S of budesonide by capillary gas chromatography on a short analytical column with Rtx®-5 stationary phase

The conditions for separation, identification and quantitative determination of epimers 22R and 22S of budesonide by capillary gas chromatography (GC) with FID detection and two various sample injection methods, namely split-splitless and cool on-column, were established. In analysis helium as carrier gas and Rtx-5 capillary column of 7 m in length along with stationary phase Crossbond 5% diphenyl-95% dimethyl polysiloxane were used. The individual epimers were identified under specified conditions by using standard samples of different declared concentration of each epimer under investigation: (1) 51.2% of epimer 22R and 47.3% of epimer 22S, and (2) 95.1% of 22R and 4.4% of 22S, as well as Pulmicort, a preparation containing micronized budesonide as an active substance. It seems that good parameters of preliminary validation achieved by the proposed methods can confirm its suitability for quantitative analysis purpose. The retention times obtained for epimers 22R and 22S, depending on injection technique are about 7.7 and. 8.3 min for split and, approx. 10.3 and 10.9 min for cool on-column. The limits of detection and quantitation are 5.7 and 6.2 ng, for 22R respectively, and 4.3 and 4.8 ng for 22S. The linearity is maintained for concentrations ranging from 0.01 to 0.20 mg/ml. The quantitative analysis features of repeatability, high precision and accuracy confirmed by the obtained results and its statistical evaluation.

A stability-indicating HPLC assay method for budesonide

The official (European) pharmacopeial assay for budesonide was found to be non-specific and non-stability-indicating when used to qualify several batches of pharmaceutical grade drug substance from different sources. In contrast, the most widely cited HPLC method in the literature was found to be specific and stability-indicating with respect to drug substance stored in the dry state. However, that method failed the pharmacopeia's assay system suitability requirements because of peak tailing. Moreover, it was unable to detect or resolve two major degradation products which resulted from drug storage in non-aqueous solution. A new stability-indicating HPLC method described here overcomes these problems. This method used a Hypersil C18 column with a mobile phase consisting of ethanol-acetonitrile phosphate buffer (pH 3.4; 25.6 mM) (2:30:68, v/v/v), a flow rate of 1.5 ml/min and UV detection at 240 nm. The purity of budesonide EP and its impurity profile (related substances) were tested using the new assay method, and the results compared to those from the two other methods described above. Solid-state and solution stressed stability samples were used to evaluate all methods. Using the novel method, the epimers of budesonide. their related impurities and degradation products were separated successfully. Validation studies demonstrated that the novel method possessed a linear UV response, good system precision and accuracy, high sensitivity and specificity for budesonide. The novel method will be used for future studies of budesonide's degradation kinetics.