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Therapeutic monoclonal antibody (mAb) products for intravenous (IV) administration generally require aseptic compounding with a commercially available diluent. When the administration site is located away from the preparation site, the prepared dosing solution may need to be transported in a vehicle. The impact of vehicle transportation on the product quality of mAbs needs to be evaluated to define safe handling and transportation conditions for dosing solutions. The design and execution of actual vehicle transportation studies require considerable resources and time. In this study, we systematically developed three different laboratory equipment-based methods that simulate vehicle transportation stresses: orbital shaker (OS), reciprocating shaker (RS), and vibration test system (VTS)-based simulation methods. We assessed their feasibility by comparing the impact on product quality caused by each simulated method with that caused by actual vehicle transportation. Without residual polysorbate 80 (PS80) in the mAb dosing solution, transportation via a cargo van led to a considerable increase in the subvisible particle counts and did not meet the compendial specifications for the light obscuration method. However, the presence of as low as 0.0004%w/v (4 ppm) PS80 in the dosing solution stabilized the mAb against vehicle transportation stresses and met the compendial specifications. Vehicle transportation of an IV bag with headspace resulted in negligible micro air bubbles and foaming in both PS80-free and PS80-containing mAb dosing solutions. These phenomena were found to be comparable to the VTS-based simulated method. However, the OS- and RS-based simulated methods formed significantly more micro air bubbles and foaming in an IV bag with headspace than either actual vehicle transportation or the VTS-based simulated method. Despite the higher interfacial stress (micro air bubbles and foaming) in the dosing solution created by the OS- and RS-based simulated methods, 0.0004%w/v (4 ppm) PS80 in the dosing solution was found to be sufficient to stabilize the mAb. The study shows that under appropriate simulated conditions, the OS-, RS-, and VTS-based simulated methods can be used as practical and meaningful models to assess the impact and risk of vehicle transportation on the quality of mAb dosing solutions.
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Monoclonal antibody (mAb) products for intravenous (IV) administration generally require aseptic compounding with a commercial diluent within a pharmacy. The prepared dosing solution in the IV bag may be transported to the dosing location via manual, vehicular, pneumatic tube system (PTS), or a combination of these methods. In this study, the type and level of physical stresses associated with these three methods and their product quality impact for relatively sensitive and stable mAbs were assessed. Vibration was found to be the main stress associated with manual and vehicle transportation methods, although this was at a relatively low level (<1 GRMS/Root-Mean-Square Acceleration). Shock and drop events, at relatively low levels, were also observed with these methods. PTS transportation showed substantially more intense shock, vibration, and drop stresses and the measured levels were up to 91 G/force of acceleration or deceleration, 3.7 GRMS and 39 G, respectively. Using a foam padding insert for PTS transportation reduced the shock level considerably (91 G to 59 G). Transportation of mAb dosing solutions in IV bags via different methods including PTS transportation variables caused a small increase in the subvisible particle counts and there was no change in submicrometer particle distribution. No visible particles and no significant change to soluble aggregate levels were observed after transportation. Strategies such as removal of IV bag headspace prior to transport and in-line filtration poststress reduced the subvisible particles counts. All tested transportation conditions showed negligible impact on other product quality attributes tested. Removal of IV bag headspace prior to PTS transport prevented formation of micro air bubbles and foaming compared to the unaltered IV bag. This study shows examples where manual, vehicle, and PTS transport methods did not significantly impact product quality, and provides evidence that mAb products that are appropriately stabilized in the dosing solution (e.g., with a surfactant) can be transported via a PTS.
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Anticorpos Monoclonais , VibraçãoRESUMO
Syringe filling of high-concentration mAb formulation during manufacturing of large-scale drug product batches may present challenges such as product deposition onto the area of the syringe barrel where the stopper is inserted, product splashing or dripping, droplets left after the fill cycle, filling needle clogging, product build-up inside the needle during line stoppages, variation in fill weight/volume, and potential impact on product quality attributes. In this article, a summary of these issues and approaches to overcome them are summarized. Potential failure modes of the syringe filling process and appropriate in-process controls are provided. In addition to developing the filling process or resolving manufacturing issues, the pharmaceutical company developing the product and associated drug product manufacturing process may want to implement long-term strategic approaches to support the portfolio progression. Potential long-term approaches such as use of a viscosity reducing formulation development approach, improving peristaltic filling technology performance, building small-scale filling capability and establishing a streamlined filling process management cycle are also summarized. The aspects summarized in this article may be used to develop a robust filling process and control strategy for high-concentration mAb products and implement long-term strategic approaches to support the portfolio progression.
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Seringas , Tecnologia Farmacêutica , Anticorpos Monoclonais , Agulhas , ViscosidadeRESUMO
Biopharmaceutical drug products may be exposed to temperatures outside of the intended storage temperature range (typically 2-8°C) during commercial distribution due to uncontrolled variables and unexpected events. Pharmaceutical companies are expected to ensure that product quality and stability are not negatively impacted by temperature excursions defined as being acceptable for the product. It is imperative that all firms involved in the distribution understand key elements of the temperature excursion management program in place to overcome the challenges of global distribution and comply with regulatory requirements. Proactive implementation of a comprehensive temperature excursion management program is expected to help achieve successful commercial distribution. In this article, important aspects related to the key elements of a comprehensive temperature excursion management program are summarized, including standard stability testing, regulatory expectations related to the justification of temperature excursions, thermal cycling studies to assess and support potential temperature excursions (including how/when thermal cycling study data is used to support temperature excursions), good distribution practices to minimize temperature excursions and use of theoretical methods/mathematical simulation models to assess temperature excursions. A comprehensive temperature excursion management program is expected to ensure product quality and help minimize, assess, and justify temperature excursions more efficiently, ensure regulatory compliance and avoid business impact caused by the loss of products or inadequate supply.
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Produtos Biológicos , Preparações Farmacêuticas , Comércio , TemperaturaRESUMO
Understanding the contribution of relevant factors to the analytical variability of the micro-flow imaging (MFI) technique is of prime importance because of the significance of the subvisible particulate data in biopharmaceutical product development. The current study was performed to determine the contribution of several key variables to the variability of the subvisible particle counts (e.g., day-to-day, vial-to-vial, sample-to-sample, and measurement-to-measurement variabilities) using a nested statistical analysis. The variability was measured in the <10 µm, ≥10 µm, ≥25 µm, and ≥50 µm size ranges along with the total particle count and the maximum and the mean particle size. The contribution of the vial to the variability of the subvisible particle counts was found to be greater than those of the other factors evaluated in the current study. The analytical method variability in terms of percent relative standard deviation with respect to the particle count in the <10 µm, ≥10 µm, and ≥25 µm size ranges was found to be 16%, 40%, and 44%, respectively. A thorough understanding of the contribution of key factors to the analytical variability revealed how the corresponding contribution can be minimized, that is, by increasing the number of vials, samples, and measurements. The results of the current study may be leveraged for the optimization of the analytical method or for minimization of the analytical variability with the MFI technique.
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Anticorpos Monoclonais/análise , Interpretação Estatística de Dados , Técnicas Analíticas Microfluídicas/métodos , Tamanho da Partícula , Liofilização/métodos , Liofilização/normas , Técnicas Analíticas Microfluídicas/normas , Agregados ProteicosRESUMO
MilliporeSigma recently introduced a new magnetically coupled single-use mixing system (Mobius® Power MIX) for more efficient mixing of buffers and media in biopharmaceutical applications. Experimental and computational fluid dynamics (CFD) assessments were performed on the Power MIX 100 system to understand product quality impact, shear, and mixing efficiency. It was interesting to note slightly higher submicron (0.4-1 µm) and subvisible (1-54 µm) particle formation at the lower mixing speed (50 RPM) compared to higher mixing speeds (100/200 RPM). Mixing speed and time showed negligible impact on the other product quality attributes tested, including protein concentration, turbidity, general appearance, purity, and soluble aggregates. The CFD simulations provided useful information with respect to the impact of batch size (20-100 L), viscosity (2-50 cP), and impeller speed (100-300 RPM) on mixing time (mixing time ranged from 10 to 365 s) and shear (maximum shear rate was found to be localized around the impeller and it was about 30,260 s-1, whereas the average shear rate ranged from 4 to 36 s-1). Statistical analysis of the CFD results showed that natural-log transformation and quadratic fitting were found to be suitable statistical models to predict mixing time and shear within the design space of the parameters assessed in the present study.
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Anticorpos Monoclonais/química , Composição de Medicamentos/métodos , Hidrodinâmica , Magnetismo/métodos , Fenômenos FísicosRESUMO
This article summarizes experimental, theoretical, and computational assessments performed to understand the effect of filling and suck-back cycle factors on fluid behaviors that increase the propensity for filling needle clogging. Product drying under ambient conditions decreased considerably when the liquid front was altered from a droplet or meniscus at the needle tip to a point approximately 5 mm inside the needle. Minimizing the variation in size of product droplet formed after the fill cycle is critical to achieve a uniform meniscus height after the suck-back cycle. Several factors were found to contribute to droplet size variability, including filling and suck-back pump speed, suck-back volume, and product temperature. Filling trials and the computational fluid dynamics simulations showed that product meniscus stability during the suck-back cycle can be improved by reducing the suck-back flow rate. The computational fluid dynamics simulations also showed that a decrease in contact angle had the greatest effect in reducing meniscus stability. As the number of filling line stoppages increases, the product buildup at the needle increases. The interaction between stoppages and the number of dispenses between stoppages was established to minimize product buildup at the filling needle. Improved suck-back control was shown to improve process capability of large-scale batches.
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Anticorpos Monoclonais/química , Embalagem de Medicamentos/métodos , Hidrodinâmica , Modelos Químicos , Química Farmacêutica , Simulação por Computador , Embalagem de Medicamentos/instrumentação , Agulhas , SeringasRESUMO
Japan represents the third largest pharmaceutical market in the world. Developing a new biopharmaceutical drug product for the Japanese market is a top business priority for global pharmaceutical companies while aligning with ethical drivers to treat more patients in need. Understanding Japan-specific key regulatory requirements is essential to achieve successful approvals. Understanding the full context of Japan-specific regulatory requirements/expectations is challenging to global pharmaceutical companies due to differences in language and culture. This article summarizes key Japan-specific regulatory aspects/requirements/expectations applicable to new drug development, approval, and postapproval phases. Formulation excipients should meet Japan compendial requirements with respect to the type of excipient, excipient grade, and excipient concentration. Preclinical safety assessments needed to support clinical phases I, II, and III development are summarized. Japanese regulatory authorities have taken appropriate steps to consider foreign clinical data, thereby enabling accelerated drug development and approval in Japan. Other important topics summarized in this article include: Japan new drug application-specific bracketing strategies for critical and noncritical aspects of the manufacturing process, regulatory requirements related to stability studies, release specifications and testing methods, standard processes involved in pre and postapproval inspections, management of postapproval changes, and Japan regulatory authority's consultation services available to global pharmaceutical companies.
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Aprovação de Drogas , Indústria Farmacêutica , Animais , Produtos Biológicos/uso terapêutico , Ensaios Clínicos como Assunto , Aprovação de Drogas/legislação & jurisprudência , Aprovação de Drogas/métodos , Composição de Medicamentos/instrumentação , Avaliação de Medicamentos/legislação & jurisprudência , Avaliação de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Indústria Farmacêutica/legislação & jurisprudência , Indústria Farmacêutica/métodos , Excipientes/química , Humanos , JapãoRESUMO
Oral cancer is among the most prevalent cancers in the world. Moreover, it is one of the major health problems and causes of death in many regions of the world. The traditional treatment modalities include surgical removal, radiation therapy, systemic chemotherapy, or a combination of these methods. In recent decades, there has been significant interest in intraoral site-specific chemoprevention via local drug delivery using polymeric systems. Because of its easy accessibility and clear visibility, the oral mucosa is amenable for local drug delivery. A variety of polymeric systems-such as gels, tablets, films, patches, injectable systems (e.g., millicylindrical implants, microparticles, and in situ-forming depots), and nanosized carriers (e.g., polymeric nanoparticles, nanofibers, polymer-drug conjugates, polymeric micelles, nanoliposomes, nanoemulsions, and polymersomes)-have been developed and evaluated for the local delivery of natural and synthetic chemopreventive agents. The findings of in vitro, ex vivo, and in vivo studies and the positive outcome of clinical trials demonstrate that intraoral site-specific drug delivery is an attractive, highly effective and patient-friendly strategy for the management of oral cancer. Intraoral site-specific drug delivery provides unique therapeutic advantages when compared to systemic chemotherapy. Moreover, intraoral drug delivery systems are self-administrable and can be removed when needed, increasing patient compliance. This article covers important aspects and advances related to the design, development, and efficacy of polymeric systems for intraoral site-specific drug delivery. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1383-1413, 2018.
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Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Sistemas de Liberação de Medicamentos/métodos , Neoplasias Bucais/prevenção & controle , Polímeros/química , Administração através da Mucosa , Animais , Humanos , Mucosa Bucal , NanopartículasRESUMO
Partial and complete clogging of filling needles occurred during syringe filling of a high-concentration mAb formulation. This caused nonvertical liquid flow, which eventually led to the termination of filling. Overcoming this phenomenon was essential to ensure minimal fill weight variation, product waste, and manufacturing downtime. The liquid behavior inside the filling needle was studied using glass and stainless steel needles and demonstrated that effective suck-back control was critical for preventing needle clogging. A key finding of our work is that the suck-back pump speed was a critical factor to achieve an effective suck back. More specifically, a slow suck-back pump speed (<10 rpm; liquid flow rate, <5 mL/min) was essential to improve suck-back control inside the conventional stainless steel filling needles. In contrast, higher suck-back pump speeds (>10 rpm; liquid flow rate, >5 mL/min) resulted in downward product migration within the filling needle leading to formation of a liquid plug at the needle tip, which was prone to rapid drying. Slowing the suck-back pump speed in conjunction with modifying the suck-back volume was effective at consistently withdrawing product into the stainless steel filling needles and prevented needle clogging.
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Anticorpos Monoclonais/química , Química Farmacêutica/métodos , Vidro/química , Agulhas , Aço Inoxidável/química , SeringasRESUMO
Herein we describe a formulation of self-encapsulating poly(lactic-co-glycolic acid) (PLGA) microspheres for vaccine delivery. Self-healing encapsulation is a novel encapsulation method developed by our group that enables the aqueous loading of large molecules into premade PLGA microspheres. Calcium phosphate (CaHPO4) adjuvant gel was incorporated into the microspheres as a protein-trapping agent for improved encapsulation of antigen. Microspheres were found to have a median size of 7.05 ± 0.31 µm, with a w/w loading of 0.60 ± 0.05% of ovalbumin (OVA) model antigen. The formulation demonstrated continuous release of OVA over a 49-day period. Released OVA maintained its antigenicity over the measured period of >21 days of release. C57BL/6 mice were immunized via the intranasal route with prime and booster doses of OVA (10 µg) loaded into microspheres or coadministered with cholera toxin B (CTB), the gold standard of mucosal adjuvants. Microspheres generated a Th2-type response in both serum and local mucosa, with IgG antibody responses approaching those generated by CTB. The results suggest that this formulation of self-encapsulating microspheres shows promise for further study as a vaccine delivery system.
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Ácido Láctico/química , Microesferas , Ácido Poliglicólico/química , Vacinas/administração & dosagem , Vacinas/química , Animais , Fosfatos de Cálcio/química , Toxina da Cólera/química , Cromatografia Líquida de Alta Pressão , Sistemas de Liberação de Medicamentos/métodos , Ensaio de Imunoadsorção Enzimática , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Varredura , Ovalbumina/química , Copolímero de Ácido Poliláctico e Ácido PoliglicólicoRESUMO
The objective of this review is to summarize recent advances in chitosan nanoparticles prepared by ionotropic gelation. Significant progress has occurred in this area since the method was first reported. The gelation technique has been improved through a number of creative methodological modifications. Ionotropic gelation via electrospraying and spinning disc processing produces nanoparticles with a more uniform size distribution. Large-scale manufacturing of the nanoparticles can be achieved with the latter approach. Hydrophobic and hydrophilic drugs can be simultaneously encapsulated with high efficiency by emulsification followed by ionic gelation. The turbulent mixing approach facilitates nanoparticle formation at a relatively high polymer concentration (5 mg/mL). The technique can be easily tuned to achieve the desired polymer/surface modifications (e.g., blending, coating, and surface conjugation). Using factorial-design-based approaches, optimal conditions for nanoparticle formation can be determined with a minimum number of experiments. New insights have been gained into the mechanism of chitosan-tripolyphosphate nanoparticle formation. Chitosan nanoparticles prepared by ionotropic gelation tend to aggregate/agglomerate in unfavorable environments. Factors influencing this phenomenon and strategies that can be adopted to minimize the instability are discussed. Ionically cross-linked nanoparticles based on native chitosan and modified chitosan have shown excellent efficacy for controlled and targeted drug-delivery applications.
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Quitosana/química , Portadores de Fármacos/química , Nanopartículas/química , Preparações Farmacêuticas/administração & dosagem , Polifosfatos/química , Materiais Biocompatíveis/química , Química Farmacêutica/métodos , Géis/química , Íons/química , Tamanho da PartículaRESUMO
Cell and growth factor-based tissue engineering has shown great potentials for skeletal regeneration. This study tested its feasibility in reconstructing large mandibular defects and compared the efficacy of varied construction materials and sealing methods. Bilateral mandibular critical-size (5-cm(3)) defects were created on six 4-month-old domestic pigs, and grafted with ß-tricalcium phosphate (ßTCP) only (Group-A), ßTCP with autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) (Group-B), and ßTCP with BM-MSCs and biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres containing bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) (Group-C). The buccal sides of Groups-B/-C were either sealed by fibrin sealant or by a biodegradable PLGA barrier membrane before soft-tissue closure. Computed tomography (CT), microCT and histology analyses were performed 12 weeks postoperatively. In vitro data demonstrated that BM-MSCs, with MSC properties confirmed, remained vital after integration with ßTCP; and PLGA microspheres exhibited an initial burst followed by slow and continuous release of growth factors over a period of 28 days. In vivo data demonstrated that Group-B/-C sites had significantly greater gap obliteration, higher tissue mineral densities and more residual ßTCP granules (p<0.05, Kruskal-Wallis tests). Qualitatively, Group-B/-C defect sites had started remodeling while Group-A sites were mainly forming new bone to bridge the gaps. Furthermore, ßTCP degradation was not mediated by macrophages or osteoclasts, and was significantly slowed down by sealing the defects with barrier membrane. Combined, these data present a promising formulation composed of ßTCP granules, autologous MSCs, controlled-release growth factors and biodegradable PLGA barrier membrane for the reconstruction of critical-size mandibular defects.
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The feasibility of various cellulose polymer derivatives, including methylcellulose (MC), hydroxypropyl methylcellulose (HPMC), sodium-carboxymethylcellulose (sodium-CMC), and cationic-hydroxyethylcellulose (cationic-HEC), for use as an excipient to enhance drug delivery in nasal spray formulations was investigated. Three main parameters for evaluating the polymers in nasal drug delivery applications include rheology, ciliary beat frequency (CBF), and permeation across nasal tissue. Reversible thermally induced viscosity enhancement was observed at near nasal physiological temperature when cellulose derivatives were combined with an additional excipient, poly(vinyl caprolactam)-poly(vinyl acetate)-poly(ethylene glycol) graft copolymer (PVCL-PVA-PEG). Cationic-HEC was shown to enhance acyclovir permeation across the nasal mucosa. None of the tested cellulosic polymers caused any adverse effects on porcine nasal tissues and cells, as assessed by alterations in CBF. Upon an increase in polymer concentration, a reduction in CBF was observed when ciliated cells were immersed in the polymer solution, and this decrease returned to baseline when the polymer was removed. While each cellulose derivative exhibited unique advantages for nasal drug delivery applications, none stood out on their own to improve more than one of the performance characteristics examined. Hence, these data may be useful for the development of new cellulose derivatives in nasal drug formulations.
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Celulose/farmacocinética , Portadores de Fármacos/farmacocinética , Mucosa Nasal/metabolismo , Aciclovir/administração & dosagem , Aciclovir/farmacocinética , Adesividade , Administração por Inalação , Animais , Células Cultivadas , Celulose/química , Cílios/efeitos dos fármacos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Estudos de Viabilidade , Mucosa Nasal/efeitos dos fármacos , Permeabilidade , Polímeros/química , Polímeros/farmacocinética , Reologia , Suínos , ViscosidadeRESUMO
An important poorly understood phenomenon in controlled-release depots involves the strong interaction between common cationic peptides and low Mw free acid end-group poly(lactic-co-glycolic acids) (PLGAs) used to achieve continuous peptide release kinetics. The kinetics of peptide sorption to PLGA was examined by incubating peptide solutions of 0.2-4mM octreotide or leuprolide acetate salts in a 0.1M HEPES buffer, pH7.4, with polymer particles or films at 4-37°C for 24h. The extent of absorption/loading of peptides in PLGA particles/films was assayed by two-phase extraction and amino acid analysis. Confocal Raman microspectroscopy, stimulated Raman scattering (SRS) and laser scanning confocal imaging, and microtome sectioning techniques were used to examine peptide penetration into the polymer phase. The release of sorbed peptide from leuprolide-PLGA particles was evaluated both in vitro (PBST+0.02% sodium azide, 37°C) and in vivo (male Sprague-Dawley rats). We found that when the PLGA-COOH chains are sufficiently mobilized, therapeutic peptides not only bind at the surface, a common belief to date, but also can be internalized and distributed throughout the polymer phase at physiological temperature forming a salt with low-molecular weight PLGA-COOH. Importantly, absorption of leuprolide into low MW PLGA-COOH particles yielded ~17 wt.% leuprolide loading in the polymer (i.e., ~70% of PLGA-COOH acids occupied), and the absorbed peptide was released from the polymer for >2 weeks in a controlled fashion in vitro and as indicated by sustained testosterone suppression in male Sprague-Dawley rats. This new approach, which bypasses the traditional encapsulation method and associated production cost, opens up the potential for facile production of low-cost controlled-release injectable depots for leuprolide and related peptides.
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Preparações de Ação Retardada/química , Ácido Láctico/química , Leuprolida/administração & dosagem , Octreotida/administração & dosagem , Ácido Poliglicólico/química , Adsorção , Animais , Composição de Medicamentos , Leuprolida/química , Masculino , Octreotida/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Sprague-DawleyRESUMO
PURPOSE: To investigate the effect of γ-irradiation of poly(lactic-co-glycolic acid) (PLGA)/Al(OH)3/0 or 5 wt% diethyl phthalate (DEP) microspheres for active self-healing encapsulation of vaccine antigens. METHODS: Microspheres were irradiated with 6°Co at 2.5 and 1.8 MRad and 0.37 and 0.20 MRad/h. Encapsulation of tetanus toxoid (TT) was achieved by mixing Al(OH)3-PLGA microspheres with TT solution at 10-38°C. Electron paramagnetic resonance (EPR) spectroscopy was used to examine free radical formation. Glass transition temperature (T(g)) and molecular weight of PLGA was measured by differential scanning calorimetry and gel permeation chromatography, respectively. Loading and release of TT were examined by modified Bradford, amino acid analysis, and ELISA assays. RESULTS: EPR spectroscopy results indicated absence of free radicals in PLGA microspheres after γ-irradiation. Antigen-sorbing capacity, encapsulation efficiency, and T(g) of the polymer were also not adversely affected. When DEP-loaded microspheres were irradiated at 0.2 MRad/h, some PLGA pores healed during irradiation and PLGA healing during encapsulation was suppressed. The molecular weight of PLGA was slightly reduced when DEP-loaded microspheres were irradiated at the same dose rate. At the 0.37 MRad/h dose rate, these trends were not observed and the full immunoreactivity of TT was preserved during encapsulation and 1-month release. Gamma irradiation slightly increased TT initial burst release. The small increase in total irradiation dose from 1.8 to 2.5 MRad had insignificant effect on the polymer and microspheres properties analyzed. CONCLUSIONS: Gamma irradiation is a plausible approach to provide a terminally sterilized, self-healing encapsulation PLGA excipient for vaccine delivery.
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Sistemas de Liberação de Medicamentos , Ácido Láctico/química , Ácido Poliglicólico/química , Esterilização , Toxoide Tetânico/administração & dosagem , Raios gama , Microesferas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Esterilização/métodos , Temperatura de TransiçãoRESUMO
Herein, we describe the detailed development of a simple and effective method to microencapsulate vaccine antigens in poly(lactic-co-glycolic acid) (PLGA) by simple mixing of preformed active self-microencapsulating (SM) PLGA microspheres in a low concentration aqueous antigen solution at modest temperature (10-38 °C). Co-encapsulating protein-sorbing vaccine adjuvants and polymer plasticizers were used to "actively" load the protein in the polymer pores and facilitate polymer self-healing at a temperature>the hydrated polymer glass transition temperature, respectively. The microsphere formulation parameters and loading conditions to provide optimal active self-healing microencapsulation of vaccine antigens in PLGA was investigated. Active self-healing encapsulation of two antigens, ovalbumin and tetanus toxoid (TT), in PLGA microspheres was adjusted by preparing blank microspheres containing different vaccine adjuvants (aluminum hydroxide (Al(OH)3) or calcium phosphate). Active loading of vaccine antigen in Al(OH)3-PLGA microspheres was found to: a) increase with an increasing loading of Al(OH)3 (0.88-3 wt.%) and addition of porosigen, b) decrease when the inner Al(OH)3/trehalose phase to 1 mL outer oil phase and size of microspheres was respectively >0.2 mL and 63 µm, and c) change negligibly by PLGA concentration and initial incubation (loading) temperature. Encapsulation of protein sorbing Al(OH)3 in PLGA microspheres resulted in suppression of self-healing of PLGA pores, which was then overcome by improving polymer chain mobility, which in turn was accomplished by coincorporating hydrophobic plasticizers in PLGA. Active self-healing microencapsulation of manufacturing process-labile TT in PLGA was found to: a) obviate micronization- and organic solvent-induced TT degradation, b) improve antigen loading (1.4-1.8 wt.% TT) and encapsulation efficiency (~97%), c) provide nearly homogeneous distribution and stabilization of antigen in polymer, and d) provide improved in vitro controlled release of antigenic TT.
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Antígenos/química , Ácido Láctico/química , Ácido Poliglicólico/química , Toxoide Tetânico/química , Vacinas , Adjuvantes Imunológicos , Hidróxido de Alumínio/química , Fosfatos de Cálcio/química , Citratos/química , Composição de Medicamentos , Microesferas , Ácidos Ftálicos/química , Plastificantes/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Trealose/químicaAssuntos
Substâncias Macromoleculares/química , Solventes/química , Animais , Bovinos , Cumarínicos/química , Composição de Medicamentos , Cinética , Ácido Láctico/química , Muramidase/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Soroalbumina Bovina/química , Temperatura , Trealose/químicaRESUMO
Systemic delivery of fenretinide in oral cancer chemoprevention trials has been largely unsuccessful due to dose-limiting toxicities and subtherapeutic intraoral drug levels. Local drug delivery, however, provides site-specific therapeutically relevant levels while minimizing systemic exposure. These studies evaluated the pharmacokinetic and growth-modulatory parameters of fenretinide mucoadhesive patch application on rabbit buccal mucosa. Fenretinide and blank-control patches were placed on right/left buccal mucosa, respectively, in eight rabbits (30 min, q.d., 10 days). No clinical or histological deleterious effects occurred. LC-MS/MS analyses of post-treatment samples revealed a delivery gradient with highest fenretinide levels achieved at the patch-mucosal interface (no metabolites), pharmacologically active levels in fenretinide-treated oral mucosa (mean: 5.65 µM; trace amounts of 4-oxo-4-HPR) and undetectable sera levels. Epithelial markers for cell proliferation (Ki-67), terminal differentiation (transglutaminase 1-TGase1) and glucuronidation (UDP-glucuronosyltransferase1A1-UGT1A1) exhibited fenretinide concentration-specific relationships (elevated TGase1 and UGT1A1 levels <5 µM, reduced Ki-67 indices >5 µM) relative to blank-treated epithelium. All fenretinide-treated tissues showed significantly increased intraepithelial apoptosis (TUNEL) positivity, implying activation of intersecting apoptotic and differentiation pathways. Human oral mucosal correlative studies showed substantial interdonor variations in levels of the enzyme (cytochrome P450 3A4-CYP3A4) responsible for conversion of fenretinide to its highly active metabolite, 4-oxo-4-HPR. Complementary in vitro assays in human oral keratinocytes revealed fenretinide and 4-oxo-4-HPR's preferential suppression of DNA synthesis in dysplastic as opposed to normal oral keratinocytes. Collectively, these data showed that mucoadhesive patch-mediated fenretinide delivery is a viable strategy to reintroduce a compound known to induce keratinocyte differentiation to human oral cancer chemoprevention trials.
Assuntos
Fenretinida/administração & dosagem , Neoplasias Bucais/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Biomarcadores Tumorais/metabolismo , Proliferação de Células/efeitos dos fármacos , Quimioprevenção/métodos , Citocromo P-450 CYP3A/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Feminino , Fenretinida/análogos & derivados , Fenretinida/metabolismo , Fenretinida/farmacocinética , Glucuronosiltransferase/metabolismo , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Mucosa Bucal/efeitos dos fármacos , Mucosa Bucal/metabolismo , Neoplasias Bucais/metabolismo , CoelhosRESUMO
The objective of this study was to enhance oral mucosal permeation of fenretinide by coincorporation of propylene glycol (PG) and menthol in fenretinide/Eudragit RL PO mucoadhesive patches. Fenretinide is an extremely hydrophobic chemopreventive compound with poor tissue permeability. Coincorporation of 5-10 wt % PG (mean J(s) = 16-23 µg cm⻲ h⻹; 158-171 µg of fenretinide/g of tissue) or 1-10 wt % PG + 5 wt % menthol (mean J(s) = 18-40 µg cm⻲ h⻹; 172-241 µg of fenretinide/g of tissue) in fenretinide/Eudragit RL PO patches led to significant ex vivo fenretinide permeation enhancement (p < 0.001). Addition of PG above 2.5 wt % in the patch resulted in significant cellular swelling in the buccal mucosal tissues. These alterations were ameliorated by combining both enhancers and reducing PG level. After buccal administration of patches in rabbits, in vivo permeation of fenretinide across the oral mucosa was greater (â¼43 µg fenretinide/g tissue) from patches that contained optimized permeation enhancer content (2.5 wt % PG + 5 wt % menthol) relative to permeation obtained from enhancer-free patch (â¼17 µg fenretinide/g tissue) (p < 0.001). In vitro and in vivo release of fenretinide from patch was not significantly increased by coincorporation of permeation enhancers, indicating that mass transfer across the tissue, and not the patch, largely determined the permeation rate control in vivo. As a result of its improved permeation and its lack of deleterious local effects, the mucoadhesive fenretinide patch coincorporated with 2.5 wt % PG + 5 wt % menthol represents an important step in the further preclinical evaluation of oral site-specific chemoprevention strategies with fenretinide.