固体口服制剂的相转化研究进展

固体口服制剂的相转化研究对选择工艺流程和研发新产品有重要意义。根据相转化机制，固相相变可以分为3种类型：多晶型的转化（polymorphic transition），水化与脱水（hydration／dehydration），玻璃化相与结晶（vierfication/crystallization）的相互转化。固体口服新制剂研究中应重视药物多晶型和无定形现象，预防和防治固相处方设计与工艺流程选择中发送的相转化。     

Role of water in the physical stability of solid dosage formulations

The interaction of moisture with pharmaceutical solids is highly crucial to an understanding of water-based processes, for example, manufacturing processes or prediction of solid dosage form stability and shelf life. Both the active pharmaceutical ingredient (API) and excipients in the formulation have different moisture sorption properties that can result in unexpected processing-induced phase transitions and they can affect solid-state phase transitions in the final dosage forms. The character of excipient effects on the stability of formulation. Phase transformations in formulations can lead to instability in physicochemical, biopharmaceutical, and processing properties of products. The aim of the present study was to investigate the water sorption properties of different excipients, model the sorption isotherms, examine the phase transitions, and identify differences of excipients in solid dosage form stability using dynamic vapor sorption analysis, near-infrared spectroscopy, and X-ray diffraction methods. The thermal processing was carried out with a variable temperature X-ray powder diffractometer to compare the dehydration behavior of wet excipients and evaluate solid-state properties during heating. These results showed that despite some limitations, moisture sorption isotherms of excipients are useful in predicting solid-state stability, interactions at early stages of formulation development, and effects of moisture on physicochemical properties of the final dosage forms.     

Influence of solid phase and formulation processing on stability of Abbott-232 tablet formulations

Abbott-232 is a chemically stable, highly water soluble non-hygroscopic compound selected for development as a potent uroselective alpha(1A) agonist. An anhydrate, a monohydrate, and an amorphous phase were isolated. The anhydrate was chosen for formulation development based on solid-state characterization. Excipients for immediate release (IR) tablet formulations were selected according to compatibility studies. However, the prototype IR tablets designed for clinical trials were found to be chemically unstable. Thus, process-induced phase transformation was investigated as the likely cause of the observed instability. Since the drug loading in the formulations was low (1%), model granulations containing 30% drug were evaluated to test this hypothesis. Investigation using a variety of analytical techniques indicated that the observed degradation was, indeed, a result of a solution-mediated phase transformation from anhydrate to amorphous Abbott-232 during wet granulation. A new direct compression formulation was, therefore, developed to prevent the solution-mediated process induced phase transition. Since the drug loading was low, a polarized light microscope (PLM) method was used to evaluate the solid phase in the new formulation. PLM confirmed that the original anhydrate form remained unchanged in tablets manufactured by the dry process. Stability studies confirmed that both IR and extended release (ER) tablets of Abbott-232 were successfully developed for clinical trials using direct compression.     

化学药品口服固体制剂生产场地变更的技术风险考量

药品生产场地变更可能会关联药品处方、原辅料供应商、生产工艺、工艺参数和批量等其他注册管理事项的变更,是所有变更情形中最复杂的。本文探讨化学药品口服固体制剂生产场地变更的技术风险考量点,结合技术审评中的部分案例,阐述了关键质量属性与关键工艺参数或关键控制指标等影响因素的关系,以期为药品生产企业变更生产场地时如何开展研究提供借鉴和启示。     

Selecting and controlling API crystal form for pharmaceutical development--strategies and processes

The success of designing, developing, manufacturing and introducing oral dosage forms of pharmaceutical products into the market relies on many steps, processes, stages and usually three phases of clinical trials. One key process is selecting an appropriate active pharmaceutical ingredient (API) crystal or amorphous form for the final dosage product: the ultimate goal of this selection process is to ensure that the manufactured product contains a stable and bioavailable active ingredient. A thorough knowledge of the solid-state chemistry of the API, the related excipients and the processes to make the product are critical in meeting this goal. Through recently published literature and the authors' experiences, this review describes the concepts and approaches that are used in the development of a truly knowledge-based crystalline API form selection process and highlights the appropriate studies which fit the Quality by Design (QbD) framework for pharmaceutical development activities. This review also discusses the potential API crystal form transformations in the API crystallization, post-crystallization and formulation stages, which are demonstrated by case study examples.     

Soft Gelatin Capsules (Softgels)

It is estimated that more than 40% of new chemical entities (NCEs) coming out of the current drug discovery process have poor biopharmaceutical properties, such as low aqueous solubility and/or permeability. These suboptimal properties pose significant challenges for the oral absorption of the compounds and for the development of orally bioavailable dosage forms. Development of soft gelatin capsule (softgel) dosage form is of growing interest for the oral delivery of poorly water soluble compounds (BCS class II or class IV). The softgel dosage form offers several advantages over other oral dosage forms, such as delivering a liquid matrix designed to solubilize and improve the oral bioavailability of a poorly soluble compound as a unit dose solid dosage form, delivering low and ultra-low doses of a compound, delivering a low melting compound, and minimizing potential generation of dust during manufacturing and thereby improving the safety of production personnel. However, due to the very dynamic nature of the softgel dosage form, its development and stability during its shelf-life are fraught with several challenges. The goal of the current review is to provide an in-depth discussion on the softgel dosage form to formulation scientists who are considering developing softgels for therapeutic compounds.     

Pharmaceutical Quality by Design: Product and Process Development, Understanding, and Control

PURPOSE: The purpose of this paper is to discuss the pharmaceutical Quality by Design (QbD) and describe how it can be used to ensure pharmaceutical quality. MATERIALS AND METHODS: The QbD was described and some of its elements identified. Process parameters and quality attributes were identified for each unit operation during manufacture of solid oral dosage forms. The use of QbD was contrasted with the evaluation of product quality by testing alone. RESULTS: The QbD is a systemic approach to pharmaceutical development. It means designing and developing formulations and manufacturing processes to ensure predefined product quality. Some of the QbD elements include: Defining target product quality profile; Designing product and manufacturing processes; Identifying critical quality attributes, process parameters, and sources of variability; Controlling manufacturing processes to produce consistent quality over time. CONCLUSIONS: Using QbD, pharmaceutical quality is assured by understanding and controlling formulation and manufacturing variables. Product testing confirms the product quality. Implementation of QbD will enable transformation of the chemistry, manufacturing, and controls (CMC) review of abbreviated new drug applications (ANDAs) into a science-based pharmaceutical quality assessment.     

Understanding processing-induced phase transformations in erythromycin-PEG 6000 solid dispersions

Since the quality and performance of a pharmaceutical solid formulation depend on solid state of the drug and excipients, a thorough investigation of potential processing-induced transformations (PITs) of the ingredients is required. In this study, the physical phenomena taking place during formulation of erythromycin (EM) dihydrate solid dispersions with polyethylene glycol (PEG) 6000 by melting were investigated. PITs were monitored in situ using variable temperature X-ray powder diffraction (VT-XRPD), differential scanning calorimetry (DSC), and hot-stage microscopy (HSM). Possible intermolecular interactions between the drug and polymer in the solid state were further studied by Fourier transform infrared (FTIR) spectroscopy. While in the absence of PEG the dehydration was the only transformation observed, hot-melt processing with the polymer caused the drug to undergo multiple phase transformations (EM dihydrate --> EM dehydrate --> EM anhydrate). This alteration in phase behavior of EM was attributed to the ability of PEG in promoting nucleation and crystal growth of the EM anhydrate through a solvent-mediated route. In situ monitoring of solid dispersion formation, especially by VT-XRPD and HSM, enabled both early-stage detection of phase transformations during the hot-melt processing and better process understanding.     

化学仿制药口服溶液剂的药学研究关注点

化学仿制药口服溶液剂是可能豁免人体生物等效性研究的口服给药剂型,其药学研究关注点与口服固体制剂、注射剂等剂型均有一定差异,但目前国内尚未出台相关药学研究技术指导原则。简要介绍了化学仿制药口服溶液剂药学研究中需要关注的问题,包括处方工艺、质量研究、稳定性研究等方面,重点关注了微生物控制方面的内容,结合审评实践提出了研究建议;同时在国内外相关法规要求的基础上,探讨了豁免人体生物等效性研究的相关要求。旨在为后续化学仿制药口服溶液剂的药学研究提供更多参考。     

In-line monitoring of hydrate formation during wet granulation using Raman spectroscopy

Process-induced transformations are very important to control during pharmaceutical manufacturing because they may change the properties of the active pharmaceutical ingredient in the drug product, compromising therapeutic efficacy. One process that may facilitate a process-induced transformation is high-shear wet granulation. In this study, the feasibility of Raman spectroscopy for in-line monitoring of the transformation of theophylline anhydrous to theophylline monohydrate during high-shear wet granulation has been evaluated. The midpoint of conversion occurred 3 min after the binder solution was added. The effects of several processing parameters were also examined, including mixing speed and monohydrate seeding. Mixing speed had the greatest effect on the transformation, where an increase in mixing speed shortened the onset time and increased the rate of transformation. In contrast, seeding with monohydrate or changing the way in which the binder was incorporated into the granules did not affect the transformation profile. The transformation kinetics observed during wet granulation were compared with those generated by a simple model describing the solvent-mediated transformation of theophylline in solution. In conclusion, these studies show that Raman spectroscopy can be used for in-line monitoring of solid-state transformations during wet granulation. In addition, for this particular compound, a simple solvent-mediated transformation model has been shown to be useful for estimating the time scale for hydrate formation during high-shear wet granulation.     

Self-emulsifying drug delivery systems: a novel approach to deliver drugs

Self-emulsifying drug delivery systems (SEDDS) are a proven method for poorly soluble substances works by increasing the solubility and bioavailability. SEDDS and isotropic mixtures, are composed of oils, surfactants, and occasionally cosolvents. The ability of these formulations and methods to produce microemulsions or fine oil-in-water (o/w) emulsions after moderate stirring and dilution by water phase along the GI tract might be a promising technique for lipophilic agents with dissolution rate-limited absorption. This review provides an outline of SEDDS''s numerous advances and biopharmaceutical elements, types, manufacturing, characterization, limitations, and future prospects. The evaluation of SEDDS and its applications are also discussed, focusing on the advances of SEDDS''s solid self-emulsifying delivery mechanism and dosage form. By integrating suitable polymer into the formulation, SEDDS may be studied for the creation of a formulation with sustained drug release. This technology''s improvement might lead to a new application in the field of medicine delivery. SEDDS has been demonstrated to be quite efficient in increasing oral bioavailability of lipophilic products. SEDDS is one of the promising methods for controlling the characteristics of medications that are not great choices for oral delivery. It is also worth mentioning that SEDDS may be made in variety of solid dosage forms that are acceptable for both oral and parenteral administration.     

Understanding critical material properties for solid dosage form design

What is the role of standardized methods for determining the impact of material properties in pharmaceutical formulation and process development? In this Perspective article, we identify material properties that are potentially important in solid dosage form design, and we review approaches linking these properties to product specifications in dry granulation process development. We also assess the potential benefits that could be obtained by standardizing the methods for determining the impact of material properties of commonly used excipients and propose a program of research to achieve the desired goal of an efficient, science-based approach for incorporating material properties in solid dosage form design.     

Melt extrusion can bring new benefits to HIV therapy

The incorporation of poorly soluble drugs into convenient oral dosage forms is one of the biggest challenges encountered in drug formulation. Melt extrusion, the process of converting a thermoplastic raw material into a product of uniform shape and density by forcing it through a die, offers one solution. Ingredients are mixed, compressed, and plasticized as they pass through a proprietary extruder, resulting in a solid dispersion or solid suspension in which the active molecules are uniformly spread through a polymeric matrix. Melt extrusion has been used in a wide range of medical applications, from stents to ophthalmic implants. Application of melt extrusion to the manufacturing of tablets is relatively new, complex, and is technically challenging. To date, only four drugs have been successfully manufactured using melt extrusion technology; however, many other pharmaceutical formulations may benefit from melt extrusion technology. Kaletra®, containing the anti-HIV protease inhibitors lopinavir and ritonavir, is the first co-formulated pharmaceutical compound to be successfully tableted using a proprietary melt extrusion process. Melt extrusion appears to have overcome the poor solubility and negligible oral bioavailability of previous experimental solid formulations of lopinavir/ritonavir. Importantly for patients, compared with the capsule formulation of Kaletra®, melt extrusion tablets require fewer doses to be taken each day, do not need to be refrigerated, and do not need to be taken with food. The melt extrusion tablet formulation of Kaletra® represents a significant step towards a simpler, more convenient dosage form for these protease inhibitors for many patients with HIV.     

Oral delivery of HIV-protease inhibitors

Strategies for optimizing the oral delivery of HIV-protease inhibitors draw from drug discovery efforts in molecular design, drug development tools in dosage formulation, and dosage regimen considerations in clinical medicine. This review outlines the evolution of these strategies for drugs that have been approved for human use, drug candidates still in development, and molecules that are no longer in development but from which valuable delivery information was obtained. Molecular design for obtaining desirable pharmacokinetics following oral administration primarily involved maximizing aqueous solubility and minimizing first-pass metabolism. Optimization of molecular design for oral drug delivery purposes is tempered by additional considerations for drug potency, toxicity, potential for interactions, and development of viral resistance. Strategies for improving oral bioavailability through dosage formulation use information from the effects of coadministered meals on drug plasma levels. Patient adherence to dosage regimens remains a major issue in assuring effective oral drug treatment and in preventing the development of resistance. Progress has been made in clinical studies where improved oral bioavailability and reductions in drug plasma level variability have been achieved with appropriate dosage regimen adjustment.     

Current status of amorphous formulation and other special dosage forms as formulations for early clinical phases

Although most chemists in the pharmaceutical industry have a good understanding on favorable physicochemical properties for drug candidates, formulators must still deal with many challenging candidates. On the other hand, formulators are not allowed to spend much time on formulation development for early phases of the clinical studies. Thus, it is basically difficult to apply special dosage form technologies to the candidates for the first-in-human formulations. Despite the availability of numerous reviews on oral special dosage forms, information on their applicability as the early phase formulation has been limited. This article describes quick review on the oral special dosage forms that may be applied to the early clinical formulations, followed by discussion focused on the amorphous formulations, which still has relatively many issues to be proved for the general use. The major problems that inhibit the use of the amorphous formulation are difficulty in the manufacturing and the poor chemical/physical stability. Notably, the poor physical stability can be critical, because of not the poor stability itself but the difficulty in the timely evaluation in the preclinical developmental timeframes. Research directions of the amorphous formulations are suggested to utilize this promising technology without disturbing the preclinical developmental timelines. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:2875–2885, 2009     

Applications of Machine Learning in Solid Oral Dosage Form Development

This review comprehensively summarizes the application of machine learning in solid oral dosage form development over the past three decades. In both academia and industry, machine learning is increasingly applied for multiple preformulation/formulation and process development studies. Further, this review provides the authors’ perspectives on how pharmaceutical scientists can use machine learning for right projects and in right ways; some key ingredients include (1) the determination of inputs, outputs, and objectives; (2) the generation of a database containing high-quality data; (3) the development of machine learning models based on dataset training and model optimization; (4) the application of trained models in making predictions for new samples. It is expected by the authors and others that machine learning will promisingly play a more important role in tomorrow's projects for solid oral dosage form development.     

Hot melt extrusion: An industrially feasible approach for casting orodispersible film

Over the recent few decades, many groups of formulation scientists are concentrating on rapid release dosage forms in oral cavity. Among all fast release dosage forms, orodispersible films are successful to attract pharmaceutical industry due to ease of formulation and extension patent life. Films are popular in patients too because of quick onset and user friendliness of dosage form. From the beginning, solvent casting has been selected as method of choice for manufacturing of orodispersible films. Solvent casting has been proved as a benchmark technology because of ease in product development, process optimization, process validation and technology transfer to production scale despite of some drawbacks like more number of unit operations involved and consumption of large quantity of solvents with controlled limits of organic volatile impurities in final formulation. The application of hot-melt extrusion (HME) in the pharmaceutical industry is consecutively increasing due to its proven innumerable advantages like solvent free continuous process with fewer unit operations and better content uniformity. Very few development activities has been initiated in the field of hot melt extruded orodispersible films so far. This extensive review covers detailed discussion of heavy duty industrial extruders, selection of downstream equipments, selection of excipients, common problems found in formulations and their remedies. Successive part of review addresses identification of critical quality attributes, quality target profile of product, criticality in selection of process parameters and material for substantial simulation in laboratory scale and production for successful technology transfer.     

Pharmaceutical development of a parenteral formulation of the novel anti-tumor agent carzelesin (U-80,244)

Summary The aim of this study was to design a parenteral dosage form for the investigational cytotoxic drag carzelesin. A stable formulation in PET (Polyethylene glycol 400/absolute ethanol/Tween 80, 6:3:1, v/v/v) was developed. The prototype, containing 0.50 mg carzelesin in 2.0 ml PET formulation, was found to be the optimal formulation in terms of solubility, stability and dosage requirements in phase I clinical trials. Quality control of the formulation showed that the pharmaceutical preparation of carzelesin in PET is not negatively influenced by the manufacturing process. Shelf life studies demonstrated that the formulation is stable for at least 1 year, when stored at –30°C in the dark. In addition, the stability of carzelesin in the PET formulation is discussed as a function of temperature, additives and after dilution in infusion fluids.     

A proposal for a drug product Manufacturing Classification System (MCS) for oral solid dosage forms

Abstract

This paper proposes the development of a drug product Manufacturing Classification System (MCS) based on processing route. It summarizes conclusions from a dedicated APS conference and subsequent discussion within APS focus groups and the MCS working party. The MCS is intended as a tool for pharmaceutical scientists to rank the feasibility of different processing routes for the manufacture of oral solid dosage forms, based on selected properties of the API and the needs of the formulation. It has many applications in pharmaceutical development, in particular, it will provide a common understanding of risk by defining what the “right particles” are, enable the selection of the best process, and aid subsequent transfer to manufacturing. The ultimate aim is one of prediction of product developability and processability based upon previous experience.

This paper is intended to stimulate contribution from a broad range of stakeholders to develop the MCS concept further and apply it to practice. In particular, opinions are sought on what API properties are important when selecting or modifying materials to enable an efficient and robust pharmaceutical manufacturing process. Feedback can be given by replying to our dedicated e-mail address (mcs@apsgb.org); completing the survey on our LinkedIn site; or by attending one of our planned conference roundtable sessions.     

Design of a Re-Dispersible High Drug Load Amorphous Formulation

Amorphous solid dispersions (ASD) are a commonly used enabling formulation technology to drive oral absorption of poorly soluble drugs. To ensure adequate solid-state stability and dissolution characteristics, the ASD formulation design typically has ≤ 25% drug loading. Exposed to aqueous media, ASD formulations can produce drug-rich colloidal dispersion with particle size < 500 nm. This in situ formation of colloidal particles requires incorporation of excess excipients in the formulation. The concept of using engineered drug-rich particles having comparable size as those generated by ASDs in aqueous media is explored with the goal of increasing drug loading in the solid dosage form. Utilizing ABT-530 as model compound, a controlled solvent-antisolvent precipitation method resulted in a dilute suspension that contained drug-rich (90% (w/w)) amorphous nanoparticles (ANP). The precipitation process was optimized to yield a suspension containing < 300 nm ANP. A systematic evaluation of formulation properties and process variables resulted in the generation of dry powders composed of 1–8 µm agglomerates of nanoparticles which in contact with water regenerated the colloidal suspension having particle size comparable to primary particles. Thus, this work demonstrates an approach to designing a re-dispersible ANP based powder containing ≥90% w/w ABT-530 that could be used in preparation of a high drug load solid dosage form.