Analysis of the Regulatory Divergence of Comparative Dissolution Requirements for Post-Approval Manufacturing Changes of Modified Release Solid Oral Dosage Forms.

This manuscript discusses global regulatory divergence of dissolution requirements for modified release solid oral dosage forms and the obstacles that must be addressed to be compliant with evolving guidance and legislation. The proliferation of local guidance documents, changing regulatory expectations, and increased legal enforcement has resulted in mismatched country-specific dissolution testing requirements and similarity criteria, and heightens industry's challenges with registration of modified release solid oral dosage forms. The lack of global harmonization and the complexity added by minor regional adaptations contributes to inefficiencies and hinders industry's goal of developing and delivering medicines. Awareness of country-specific similarity requirements and alignment between industry leaders and regulators is needed to facilitate global harmonization which will enable delivering new and improved medicines. The purpose of this manuscript is to compare and contrast in vitro conditions stated in local regulatory guidelines, raise awareness of the need to work toward harmonization of global requirements, and propose an initial study design toward that aspiration.

Applications of Clinically Relevant Dissolution Testing: Workshop Summary Report.

This publication summarizes the proceedings of day 3 of a 3-day workshop on "Dissolution and Translational Modeling Strategies Enabling Patient-Centric Product Development." Specifically, this publication discusses the current approaches in building clinical relevance into drug product development for solid oral dosage forms, along with challenges that both industry and regulatory agencies are facing in setting clinically relevant drug product specifications (CRDPS) as presented at the workshop. The concept of clinical relevance is a multidisciplinary effort which implies an understanding of the relationship between the critical quality attributes (CQAs) and their impact on predetermined clinical outcomes. Developing this level of understanding, in many cases, requires introducing deliberate but meaningful variations into the critical material attributes (CMAs) and critical process parameters (CPPs) to establish a relationship between the resulting in vitro dissolution/release profiles and in vivo PK performance, a surrogate for clinical outcomes. Alternatively, with the intention of improving the efficiency of the drug product development process by limiting the burden of conducting in vivo studies, this understanding can be either built, or at least enhanced, through in silico efforts, such as IVIVC and physiologically based pharmacokinetic (PBPK) absorption modeling and simulation (M&S). These approaches enable dissolution testing to establish safe boundaries and reject drug product batches falling outside of the established safe range (e.g., due to inadequate in vivo performance) enabling the method to become clinically relevant. Ultimately, these efforts contribute towards patient-centric drug product development and allow regulatory flexibility throughout the lifecycle of the drug product.

Dissolution Similarity Requirements: How Similar or Dissimilar Are the Global Regulatory Expectations?

The objective of this article is to compare and contrast the international expectations associated with the model-independent similarity factor approach to comparing dissolution profiles. This comparison highlights globally divergent regulatory requirements to meet local dissolution similarity requirements. In effect, experiments customized to meet the current international regulatory expectations for dissolution and drug release unnecessarily increase manufacturing costs, hinder science and risk-based approaches, increase collective regulatory burden, reduce continuous improvement and innovation, and potentially delay patient access to urgently needed medication. Comparative assessment of regulatory differences in applying dissolution to demonstrate product similarity is crucial to reduce non-scientifically justified experiments and foster collaborative harmonization among global regulatory health authorities and the pharmaceutical industry.

Intratracheal budesonide-poly(lactide-co-glycolide) microparticles reduce oxidative stress, VEGF expression, and vascular leakage in a benzo(a)pyrene-fed mouse model.

The purpose of this study was to determine whether intratracheally instilled polymeric budesonide microparticles could sustain lung budesonide levels for one week and inhibit early biochemical changes associated with benzo(a)pyrene (B[a]P) feeding in a mouse model for lung tumours. Polymeric microparticles of budesonide-poly (DL-lactide-co-glycolide) (PLGA 50:50) were prepared using a solvent evaporation technique and characterized for their size, morphology, encapsulation efficiency, and in-vitro release. The microparticles were administered intratracheally (i.t.) to B[a]P-fed A/J mice. At the end of one week drug levels in the lung tissue and bronchoalveolar lavage (BAL) were estimated using HPLC and compared with systemic (intramuscular) administration. In addition, in-vivo end points including malondialdehyde (MDA), glutathione (GSH), total protein levels and vascular endothelial growth factor (VEGF) in BAL, and VEGF and c-myc mRNA levels in the lung tissue were assessed at the end of one week following intratracheal administration of budesonide microparticles. Budesonide-PLGA microparticles (1-2 microm), with a budesonide loading efficiency of 69-94%, sustained in-vitro budesonide release for over 21 days. Compared with the intramuscular route, intratracheally administered budesonide-PLGA microparticles resulted in higher budesonide levels in the BAL and lung tissue. In-vivo, B[a]P-feeding increased BAL MDA, lung VEGF mRNA, lung c-myc mRNA, BAL total protein, and BAL VEGF levels by 60, 112, 71, 154, and 78%, respectively, and decreased BAL GSH by 62%. Interestingly, intratracheally administered budesonide-PLGA particles inhibited these biochemical changes. Thus, biodegradable budesonide microparticles sustained budesonide release and reduced MDA accumulation, GSH depletion, vascular leakage, and VEGF and c-myc expression in B[a]P-fed mice, indicating the potential of locally delivered sustained-release particles for inhibiting angiogenic factors in lung cancer.

Preparation of budesonide- and indomethacin-hydroxypropyl-beta-cyclodextrin (HPBCD) complexes using a single-step, organic-solvent-free supercritical fluid process.

The purpose of this study was to determine whether budesonide- and indomethacin-hydroxypropyl-beta-cyclodextrin (HPBCD) complexes could be formed using a supercritical fluid (SCF) process. The process involved the exposure of drug-HPBCD mixtures to supercritical carbon dioxide (SC CO2). The ability of the SCF process to form complexes was assessed by determining drug dissolution, drug crystallinity, and drug-excipient interactions. Drug dissolution was assessed using a HPLC assay. Crystallinity was assessed using powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). Drug-excipient interactions were characterized using Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) was used to determine any morphological changes. SC CO2 process did not alter the dissolution rate of pure drugs but resulted in two- and three-fold higher dissolution rates for budesonide- and indomethacin-HPBCD mixtures, respectively. SCF-processed mixtures exhibited a disappearance of the crystalline peaks of the drugs (PXRD), a partial or complete absence of the melting endotherm of the drugs (DSC), and a shift in the C=O stretching of the carboxyl groups of the drugs (FTIR), consistent with the loss of drug crystallinity and formation of intermolecular bonds with HPBCD. SEM indicated no discernible drug crystals upon physical mixing with or without SCF processing. Thus, budesonide- and indomethacin-HPBCD complexes with enhanced dissolution rate can be formed using a single-step, organic solvent-free SC CO2 process.

Evidence for LHRH-receptor expression in human airway epithelial (Calu-3) cells and its role in the transport of an LHRH agonist.

PURPOSE: To determine whether LHRH-receptor is expressed in Calu-3, a human bronchial epithelial cell line, and to further determine whether this receptor plays a role in the transport of deslorelin, an LHRH agonist. METHODS: Using cultured monolayers of Calu-3 grown at air-interface, the presence and localization of LHRH-receptors in Calu-3 cells was determined using immunochemical methods. To determine the mechanisms of deslorelin transport, the directionality [apical-basolateral (A-B) and basolateral-apical (B-A)] of deslorelin transport across Calu-3 monolayers and the effects of temperature (37 degrees C and 4 degrees C) and an energy depletor (2,4-dinitrophenol) were investigated. To determine the role of LHRH-receptor in deslorelin transport across Calu-3 monolayers, the influence of an LHRH-receptor antisense oligonucleotide on the LHRH-receptor expression and deslorelin transport was studied. Also, the effect of a competing LHRH agonist, buserelin, on deslorelin transport was determined. RESULTS: Immunofluorescence studies indicated the predominance of LHRH-receptor in Calu-3 cells at the apical and lateral surfaces. Western blot and RT-PCR studies further confirmed the expression of LHRH-receptor in Calu-3 cells. Deslorelin transport across Calu-3 monolayers was vectorial, with the cumulative A-B transport (1.79 +/- 0.29%) at the end of 240 min being higher than the B-A transport (0.34 +/- 0.11%). Low temperature as well as 2,4-dinitrophenol abolished this directionality. LHRH-receptor antisense oligonucleotide decreased the receptor expression at the mRNA and protein level and reduced the A-B deslorelin transport by 55 +/- 4%, without affecting the B-A transport, suggesting a role for LHRH-receptor in the vectorial transport of deslorelin. In addition, buserelin reduced the A-B deslorelin transport by 56 +/- 5% without affecting the B-A transport. CONCLUSIONS: Taken together, our results provide evidence that deslorelin is transported across the respiratory epithelium via the LHRH-receptor.

Subconjunctival nano- and microparticles sustain retinal delivery of budesonide, a corticosteroid capable of inhibiting VEGF expression.

PURPOSE: The purpose of this study was to determine whether budesonide inhibits expression of vascular endothelial growth factor (VEGF) in a retinal pigment epithelial cell line (ARPE-19) and to determine whether subconjunctivally administered budesonide nano- and microparticles sustain retinal drug levels. METHODS: The effect of budesonide (100 pM to 10 microM) on VEGF secretion, expression of VEGF mRNA, and cytotoxicity were determined in ARPE-19 cells by ELISA, RT-PCR, and a cell-viability assay, respectively. To determine the involvement of glucocorticoid receptor in the observed effects of budesonide, secretion and mRNA expression studies were also performed in the presence of a glucocorticoid receptor antagonist (RU486). DL-Polylactide (PLA) nano- and microparticles containing budesonide were prepared by a solvent evaporation technique, and the particles were characterized for size, morphology, encapsulation efficiency, and in vitro release. Budesonide-PLA nano- and microparticles were administered subconjunctivally to one eye of Sprague-Dawley rats and drug levels in the retina, vitreous, lens, and cornea of both eyes were determined at the end of 1, 7, and 14 days. RESULTS: At concentrations devoid of cytotoxicity, budesonide inhibited VEGF secretion as well as mRNA expression in ARPE-19 cells in a dose-dependent manner. RU486 treatment prevented budesonide-mediated inhibition of VEGF secretion and VEGF mRNA expression. Budesonide-PLA nano- (345 nm) and microparticles (3.6 microm), with an encapsulation efficiency of 65% and 99%, respectively, sustained budesonide release in vitro. After subconjunctival administration, both budesonide-PLA nano- and microparticles produced sustained budesonide levels in the retina and other ocular tissues. CONCLUSIONS: Budesonide is capable of inhibiting VEGF expression through glucocorticoid receptor activity. Subconjunctivally administered budesonide-PLA nano- and microparticles sustain retinal drug delivery.

Budesonide reduces multidrug resistance-associated protein 1 expression in an airway epithelial cell line (Calu-1).

The objective of this study was to determine the expression and activity of multidrug resistance-associated protein (MRP1) in a human airway epithelial cell line (Calu-1) and to further assess whether budesonide, a potent antiasthma corticosteroid, alters the expression and activity of MRP1 in these cells. Reverse transcriptase polymerase chain reaction (RT-PCR) and the Western blot analysis demonstrated the MRP1 mRNA and MRP1 protein in Calu-1 cells. Indomethacin, probenecid, and verapamil significantly enhanced the fluorescein accumulation and reduced the fluorescein efflux, consistent with the MRP1 activity in the Calu-1 cells. Following 14-day budesonide treatment, fluorescein accumulation increased and fluorescein efflux decreased, consistent with the inhibition of MRP1 activity by budesonide. At a concentration (10 microM) devoid of cytotoxicity, budesonide treatment decreased MRP1 mRNA and MRP1 protein expression in Calu-1 cells by 38% and 42%, respectively. In addition, budesonide (10 microM) enhanced the sensitivity of the MRP1 overexpressing COR-L23R cells to vincristine, suggesting the chemosensitizing effect of budesonide. Thus, budesonide inhibits MRP1 expression and may be useful as a chemosensitizer in tumor chemotherapy.

Preparation of budesonide and budesonide-PLA microparticles using supercritical fluid precipitation technology.

The objective of this study was to prepare and characterize microparticles of budesonide alone and budesonide and polylactic acid (PLA) using supercritical fluid (SCF) technology. A precipitation with a compressed antisolvent (PCA) technique employing supercritical CO2 and a nozzle with 100- microm internal diameter was used to prepare microparticles of budesonide and budesonide-PLA. The effect of various operating variables (temperature and pressure of CO2 and flow rates of drug-polymer solution and/or CO2) and formulation variables (0.25%, 0.5%, and 1% budesonide in methylene chloride) on the morphology and size distribution of the microparticles was determined using scanning electron microscopy. In addition, budesonide-PLA particles were characterized for their surface charge and drug-polymer interactions using a zeta meter and differential scanning calorimetry (DSC), respectively. Furthermore, in vitro budesonide release from budesonide-PLA microparticles was determined at 37 degrees C. Using the PCA process, budesonide and budesonide-PLA microparticles with mean diameters of 1 to 2 microm were prepared. An increase in budesonide concentration (0.25%-1% wt/vol) resulted in budesonide microparticles that were fairly spherical and less agglomerated. In addition, the size of the microparticles increased with an increase in the drug-polymer solution flow rate (1.4-4.7 mL/min) or with a decrease in the CO2 flow rate (50-10 mL/min). Budesonide-PLA microparticles had a drug loading of 7.94%, equivalent to approximately 80% encapsulation efficiency. Budesonide-PLA microparticles had a zeta potential of -37 +/- 4 mV, and DSC studies indicated that SCF processing of budesonide-PLA microparticles resulted in the loss of budesonide crystallinity. Finally, in vitro drug release studies at 37 degrees C indicated 50% budesonide release from the budesonide-PLA microparticles at the end of 28 days. Thus, the PCA process was successful in producing budesonide and budesonide-PLA microparticles. In addition, budesonide-PLA microparticles sustained budesonide release for 4 weeks.