Selection of a discriminant and biorelevant in vitro dissolution test for the development of fenofibrate self-emulsifying lipid-based formulations.

Fenofibrate, a BCS class II compound, has a low bioavailability especially when taken orally on an empty stomach. The challenge to find a new formulation for providing bioavailability, independent of food, is still ongoing. If the development of a suitable oral delivery formulation of BCS class II compounds is a frequent and great challenge to formulation scientists, the in vitro evaluation of these new formulations is also a great challenge. The purpose of this study was therefore to select an in vitro dissolution test that would be useful and as biorelevant as possible for the development of fenofibrate self-emulsifying lipid-based formulations. In this context, three different fenofibrate formulations, for which in vivo data are available in the literature, were tested using different dissolution tests until we found the one that was the most suitable. As part of this approach, we started with the simplest in vitro dissolution tests and progressed to tests that were increasingly more complex. The first tests were different single phase dissolution tests: a test under sink conditions based on the USP monograph, and different tests under non-sink conditions in non-biorelevant and biorelevant media. Given the inconclusive results obtained with these tests, biphasic dissolution systems were then tested: one with USP apparatus type II alone and another which combined USP apparatus types II and IV. This last combined test seemed the most suitable in vitro dissolution test for the development of the future fenofibrate lipid-based formulations we intend to develop in our own laboratory.

In vitro approach to study the synergistic effects of tobramycin and clarithromycin against Pseudomonas aeruginosa biofilms using prokaryotic or eukaryotic culture media.

Recurrent Pseudomonas aeruginosa infections involving biofilm formation are frequent in cystic fibrosis, aggravating the respiratory distress. Co-administration of clarithromycin and classical tobramycin could improve the health status of patients. Antibiotic toxicity was assessed on epithelial (CFBE41o(-)) and macrophagic (THP-1) cell lines. Non-toxic concentrations of antibiotics alone or in combination were applied twice daily for 12 days on mature (12-day-old) biofilms of three P. aeruginosa strains, developed either in prokaryotic culture broth [tryptic soy broth (TSB)] or in a eukaryotic cell culture medium (RPMI-FCS) more similar to an in vivo environment. The antibiofilm and bactericidal effects of antibiotics were assessed. No toxicity of tobramycin was observed on eukaryotic cell lines at concentrations up to 500µg/mL, whilst 100µg/mL was selected as the clarithromycin upper safe limit. The amount of biofilm was strongly reduced by 100µg/mL and 500µg/mL tobramycin for each strain in both media, whilst clarithromycin was only effective in RPMI-FBS, with synergistic (PAO1 strain) and additive (PYO2 strain) effects detected when combining tobramycin 4µg/mL and clarithromycin 100µg/mL. Finally, tobramycin at ≥100µg/mL exerted strong bactericidal effects on each strain in both media. Clarithromycin also exerted bactericidal effects on each strain in both media; its effect was weaker than tobramycin in TSB but was similar in RPMI-FBS. Synergistic effects were observed on PAO1 and MUCO biofilms, e.g. when combining tobramycin 4µg/mL and clarithromycin 100µg/mL. These in vitro data show that co-administration of clarithromycin and tobramycin acts synergistically against in vitro P. aeruginosa biofilms.

The Lidose hard capsule formulation of fenofibrate is suprabioavailable compared to the nanoparticle tablet formulation under high-fat fed conditions.

PURPOSE: The therapeutic equivalence of multiple registered fenofibrate formulations, several of which are suprabioavailable and therefore marketed at lower dosage strengths than their reference products, is based on the results of bioequivalence studies. Most of these formulations show a higher bioavailability when taken with a high-fat meal. The relative bioavailability of two of these formulations, the 200 mg Lidose hard capsules and the 145 mg nanoparticle tablets, was assessed when taken with a high-fat meal. METHODS: In this single dose, 2-way, randomized, crossover study, 24 healthy subjects received a 200 mg fenofibrate Lidose hard capsule (Test) and a 145 mg nanoparticle tablet (Reference) under high-fat fed conditions. Plasma concentrations of fenofibric acid were measured up to 72 hours by using a validated LC-MS/MS method. RESULTS: The geometric mean ratios (Test/Reference) and the 90% confidence intervals for AUC0-t and Cmax were 1.37 (131.58 - 142.88) and 1.38 (124.60 - 152.93), respectively. The median (range) Tmax- values of fenofibric acid were 4.5 h (3.0 - 8.0 h) and 3.25 h (1.0 - 6.5 h) after administration of the Lidose hard capsule and the nanoparticle tablet, respectively. CONCLUSION: Under high-fat fed conditions the extent of fenofibrate absorption was 37% higher for the 200 mg Lidose hard capsule compared to the 145 mg nanoparticle tablet, which is exactly as expected based on a mg-to-mg weight basis. The results of the present study underline the importance of assessing bioequivalence of fenofibrate formulations under identical fed conditions, and preferentially after a high-fat meal as this condition represents the worst-case scenario. Furthermore, the results of this study demonstrate that the 145 mg nanoparticle tablet is not bioequivalent to the 200 mg Lidose hard capsule when administered under high-fat meal conditions.

Optimization of a PGSS (particles from gas saturated solutions) process for a fenofibrate lipid-based solid dispersion formulation.

The aim of this study was to develop a formulation containing fenofibrate and Gelucire(®) 50/13 (Gattefossé, France) in order to improve the oral bioavailability of the drug. Particles from gas saturated solutions (PGSS) process was chosen for investigation as a manufacturing process for producing a solid dispersion. The PGSS process was optimized according to the in vitro drug dissolution profile obtained using a biphasic dissolution test. Using a design of experiments approach, the effects of nine experimental parameters were investigated using a PGSS apparatus provided by Separex(®) (Champigneulles, France). Within the chosen experimental conditions, the screening results showed that the drug loading level, the autoclave temperature and pressure, the connection temperature and the nozzle diameter had a significant influence on the dissolution profile of fenofibrate. During the optimization step, the three most relevant parameters were optimized using a central composite design, while other factors remained fixed. In this way, we were able to identify the optimal production conditions that would deliver the highest level of fenofibrate in the organic phase at the end of the dissolution test. The closeness between the measured and the predicted optimal dissolution profiles in the organic phase demonstrated the validity of the statistical analyses.

Thorough characterization of a Self-Emulsifying Drug Delivery System with Raman hyperspectral imaging: a case study.

Newly developed drugs often have poor bioavailability due to their poor water solubility (BCS class 2 drugs). It is therefore necessary to develop new strategies to enhance their solubility and their activity, among which, Self-Emulsifying Drug Delivery System (SEDDS). The efficacy of the drugs contained in these preparations is mainly affected by the solid state and the particle size of the active pharmaceutical ingredient (API). However, it is quite complex, long and expensive to characterize these parameters with classical techniques such as X-ray powder diffraction, differential scanning calorimetry or hot stage microscopy. The present article presents, through a case study, the advantages of the Raman hyperspectral imaging in the characterization of such formulations. Indeed, Raman chemical imaging may fully characterize SEDDS with single equipment and operator in a non-destructive way allowing the follow-up of the formulation during stability studies. Raman imaging is therefore a tool of choice in the PAT framework since it increases the knowledge of the formulation and the process. A quantitative multivariate method using Raman hyperspectral imaging to assay the API in the lipid based formulation has been developed and fully validated following the "total error" approach.

A new criterion to assess distributional homogeneity in hyperspectral images of solid pharmaceutical dosage forms.

During galenic formulation development, homogeneity of distribution is a critical parameter to check since it may influence activity and safety of the drug. Raman hyperspectral imaging is a technique of choice for assessing the distributional homogeneity of compounds of interest. Indeed, the combination of both spectroscopic and spatial information provides a detailed knowledge of chemical composition and component distribution. Actually, most authors assess homogeneity using parameters of the histogram of intensities (e.g. mean, skewness and kurtosis). However, this approach does not take into account spatial information and loses the main advantage of imaging. To overcome this limitation, we propose a new criterion: Distributional Homogeneity Index (DHI). DHI has been tested on simulated maps and formulation development samples. The distribution maps of the samples were obtained without validated calibration model since different formulations were under investigation. The results obtained showed a linear relationship between content uniformity values and DHI values of distribution maps. Therefore, DHI methodology appears to be a suitable tool for the analysis of homogeneity of distribution maps even without calibration during formulation development.

Building the quality into pellet manufacturing environment--feasibility study and validation of an in-line quantitative near infrared (NIR) method.

The present study focuses on the implementation of an in-line quantitative near infrared (NIR) spectroscopic method for determining the active content of pharmaceutical pellets. The first aim was to non-invasively interface a dispersive NIR spectrometer with four realistic particle streams existing in the pellets manufacturing environment. Regardless of the particle stream characteristics investigated, NIR together with Principal Component Analysis (PCA) was able to classify the samples according to their active content. Further, one of these particle stream interfaces was non-invasively investigated with a FT-NIR spectrometer. A predictive model based on Partial Least Squares (PLS) regression was able to determine the active content of pharmaceutical pellets. The NIR method was finally validated with an external validation set for an API concentration range from 80 to 120% of the targeted active content. The prediction error of 0.9% (root mean standard error of prediction, RMSEP) was low, indicating the accuracy of the NIR method. The accuracy profile on the validation results, an innovative approach based on tolerance intervals, demonstrated the actual and future performance of the in-line NIR method. Accordingly, the present approach paves the way for real-time release-based quality system.

Using tolerance intervals in pre-study validation of analytical methods to predict in-study results. The fit-for-future-purpose concept.

It is recognized that the purpose of validation of analytical methods is to demonstrate that the method is suited for its intended purpose. Validation is not only required by regulatory authorities, but is also a decisive phase before the routine use of the method. For a quantitative analytical method the objective is to quantify the target analytes with a known and suitable accuracy. For that purpose, first, a decision about the validity of the method based on prediction is proposed: a method is declared proper for routine application if it is considered that most of the future results generated will be accurate enough. This can be achieved by using the "beta-expectation tolerance interval" (accuracy profile) as the decision tool to assess the validity of the analytical method. Moreover, the concept of "fit-for-purpose" is also proposed here to select the most relevant response function as calibration curve, i.e. choosing a response function based solely on the predicted results this model will allow to obtain. This paper reports four case studies where the results obtained with quality control samples in routine were compared to predictions made in the validation phase. Predictions made using the "beta-expectation tolerance interval" are shown to be accurate and trustful for decision making. It is therefore suggested that an adequate way to conciliate both the objectives of the analytical method in routine analysis and those of the validation step consists in taking the decision about the validity of the analytical method based on prediction of the future results using the most appropriate response function curve, i.e. the fit-for-future-purpose concept.

Deposition and pharmacokinetics of budesonide from the Miat Monodose inhaler, a simple dry powder device.

Dry powder inhalers (DPIs) are used to deliver asthma drugs to patients, but lung deposition may depend upon the degree of inspiratory effort. The pulmonary deposition of the glucocorticosteroid budesonide (SMB-Galephar) has been assessed in 12 asthmatic patients when delivered by the Monodose inhaler (Miat, Milan, Italy); the Pulmicort Turbuhaler DPI (AstraZeneca, Lund, Sweden) was used as a comparator product. Patients inhaled from each device with maximal or sub-maximal inspiratory effort: Monodose inhaler 90 vs 45 l/min; Turbuhaler DPI 60 vs 30 l/min. The formulations were radiolabelled with (99m)Tc, and deposition of budesonide was quantified by gamma scintigraphy. Mean (SD) whole lung deposition for the Monodose inhaler (% capsule dose), was independent of inspiratory effort (maximal: 21.4 (4.3)%; sub-maximal: 21.4 (7.5)%), while lung deposition for the Turbuhaler DPI (% metered dose) fell significantly with decreasing inspiratory effort (maximal: 25.1 (6.1)%; sub-maximal: 18.5 (6.5)%; P<0.05). The plasma concentrations of budesonide showed the same trends as the whole lung deposition data. The Monodose inhaler showed inspiratory effort-independent drug delivery characteristics, and could prove be a valuable low-cost alternative to more complex devices such as the Turbuhaler DPI. The Monodose inhaler may be especially useful in groups of patients unable to inhale maximally through DPIs, including young children and adult patients with severe respiratory impairment.

Randomised crossover studies of the bioequivalence of two fenofibrate formulations after administration of a single oral dose in healthy volunteers.

Bioequivalence of a newly developed semi-solid formulation (Lidose) of fenofibrate (CAS 49562-28-9), and a reference, micronized formulation of fenofibrate was investigated in two randomised, open-label clinical studies with a crossover design. Both studies involved two distinct groups of 24 healthy volunteers. Doses of 67 mg and 200 mg, respectively, were used in study 1 and study 2. On day 1, a single oral dose was administered to all subjects, using one of the two formulations to be compared. Single oral dosing with the other formulation occurred after a washout period of at least 8 days. Blood samples were taken after each dosing for measurement of plasma fenofibric acid concentrations by high-performance liquid chromatography (HPLC) combined with fluorescence detection, and plasma pharmacokinetic parameters were determined. No statistically significant differences were noted for Cmax, Tmax, AUC0-t and AUC0-variation of between subjects treated with the new formulation and those receiving the reference formulation. Side effects were mild and not significantly different between the two fenofibrate preparations. These two studies based on validated methods demonstrate that the new and the reference fenofibrate formulations are bioequivalent when administered at the two doses studied.