Medical Grade Sodium Alginate

Medical Grade Sodium Alginate Market Outlook

The global medical grade sodium alginate market was valued at approximately USD 300 million in 2023, with a projected compound annual growth rate (CAGR) of around 6.5% during the forecast period of 2025-2035. This growth can be attributed to the increasing demand for advanced wound care products and the rising prevalence of chronic diseases, which necessitate effective treatment options. Additionally, the expanding applications of sodium alginate in various medical fields, such as drug delivery systems and tissue engineering, are driving market expansion. Furthermore, the growing awareness regarding the benefits of natural and biocompatible materials in healthcare is propelling the adoption of medical-grade sodium alginate. As research and innovation continue to advance in this field, the market is expected to witness significant growth, bolstered by the increasing investments in healthcare infrastructure worldwide.

Growth Factor of the Market

The medical grade sodium alginate market is primarily driven by the rising demand for biocompatible materials in the healthcare sector. As more medical professionals and researchers acknowledge the advantages of sodium alginate—such as its excellent gelling properties, biocompatibility, and biodegradability—there has been a noticeable shift towards its utilization in various medical applications. The surge in chronic diseases, especially in an aging global population, has led to a higher demand for effective wound care solutions, which often leverage the unique properties of sodium alginate. Furthermore, innovations in drug delivery systems using sodium alginate are enhancing patient compliance and therapeutic effectiveness, thus promoting its widespread adoption. The increasing focus on tissue engineering and regenerative medicine is also expected to enhance the market's growth trajectory. Lastly, the ongoing research and development activities aimed at discovering new applications for sodium alginate are likely to unveil new market opportunities in the coming years.

Key Highlights of the Market

• The global medical grade sodium alginate market is projected to grow at a CAGR of 6.5% from 2025-2035.
• Powder form of sodium alginate is anticipated to hold the largest market share due to its versatility and ease of use.
• The wound dressings application segment is expected to dominate the market, driven by the rising incidence of chronic wounds.
• North America is projected to be the leading region in terms of market share, bolstered by advanced healthcare infrastructure.
• Online stores are anticipated to witness the fastest growth among distribution channels, driven by the convenience of purchasing medical supplies online.

By Product Type

Powder :

The powder form of medical grade sodium alginate is widely utilized due to its versatility and ease of incorporation into various formulations. This product type is favored in applications such as wound dressings and controlled drug delivery systems because it can be easily mixed with other excipients to create desired formulations. The granular consistency allows for targeted applications, making it a popular choice among healthcare professionals. As the demand for more effective and reliable medical products increases, the powder form is expected to maintain a significant market share. Moreover, the ability to customize the properties of sodium alginate powder—such as viscosity and gel strength—further enhances its appeal in the medical field. Given the increasing focus on wound care solutions, the powder segment is poised for substantial growth in the upcoming years.

Granules :

Granulated sodium alginate presents a unique format that allows for efficient handling and application in various medical settings. This product type is particularly advantageous for applications that require precise dosing and controlled release, as the granules can be accurately measured and mixed with other components. The granule form is often used in tissue engineering scaffolds, where its porous structure supports cellular growth and tissue regeneration. Additionally, granulated sodium alginate can be utilized in dental impressions, providing excellent detail and accuracy. The demand for granules is likely to rise as more healthcare professionals recognize their benefits in various applications. The growing trend of personalized medicine is expected to further drive the need for granulated formulations, making them a key player in the market.

Gel :

Gel forms of medical grade sodium alginate have garnered attention due to their unique physicochemical properties, which enable them to form stable gels upon contact with calcium ions. This property is particularly beneficial for applications such as wound dressings, where gel forms can provide a moist healing environment and facilitate efficient healing processes. Sodium alginate gels are also used in drug delivery systems, allowing for sustained and controlled release of therapeutic agents. The gel form's biocompatibility ensures that it can safely interact with biological tissues, further enhancing its utility in medical applications. The market for sodium alginate gels is expected to grow as more innovative formulations are developed to meet the specific needs of patients. The increasing emphasis on advanced wound care solutions is anticipated to further boost the demand for gel forms in the healthcare sector.

By Application

Wound Dressings :

The wound dressings segment is a significant application area for medical grade sodium alginate, driven by the increasing prevalence of chronic wounds, pressure ulcers, and surgical wounds. Sodium alginate-based dressings provide an optimal healing environment by maintaining moisture, which is critical for the wound healing process. These dressings can absorb exudates and form a gel-like consistency that promotes healing while preventing infection. As the global geriatric population continues to grow, the incidence of chronic wounds is expected to rise, thereby increasing the demand for advanced wound care solutions. The ability of sodium alginate to promote healing while being biocompatible makes it a preferred choice among healthcare professionals. Consequently, this segment is projected to witness robust growth in the coming years, in line with the overall expansion of the medical-grade sodium alginate market.

Dental Impressions :

Another significant application of medical grade sodium alginate is in the creation of dental impressions. Sodium alginate's excellent flow properties and ability to capture fine details make it an ideal material for dental professionals when obtaining impressions of patients' teeth and gums. The quick-setting ability of sodium alginate allows for efficient workflows in dental practices, enhancing patient comfort and optimizing time management for dentists. Additionally, the material's affordability and ease of use contribute to its popularity in dental settings. As dental health awareness continues to rise globally, the demand for effective and reliable dental impression materials is expected to increase, further solidifying sodium alginate's position in this market segment.

Controlled Release Drug Delivery Systems :

Controlled release drug delivery systems are gaining traction as an innovative application of medical grade sodium alginate. This material's ability to form hydrogels facilitates the gradual release of drugs over extended periods, providing sustained therapeutic effects while minimizing side effects. Sodium alginate’s biocompatibility and biodegradability make it an ideal candidate for drug delivery applications, particularly in targeted therapies. As the pharmaceutical industry continues to seek more efficient and patient-friendly delivery methods, the demand for sodium alginate-based systems is expected to rise significantly. The potential for customized drug release profiles and the ability to incorporate a variety of therapeutic agents further enhance the appeal of sodium alginate in this domain, paving the way for promising advancements in drug delivery technologies.

Tissue Engineering :

In the realm of tissue engineering, medical grade sodium alginate plays a crucial role owing to its favorable properties for cell encapsulation and scaffold creation. The material's biocompatibility allows for the safe interaction with living cells, making it suitable for regenerative medicine applications. Sodium alginate scaffolds can provide structural support for cell attachment and growth, which are essential for tissue regeneration. The versatility of sodium alginate enables the incorporation of various bioactive molecules, enhancing cell proliferation and differentiation. As the field of tissue engineering continues to evolve, the demand for sodium alginate-based products is expected to grow, driven by advancements in regenerative therapies and the ongoing search for effective solutions to restore damaged tissues.

Gastrointestinal Disorders :

Medical grade sodium alginate is increasingly recognized for its therapeutic applications in managing gastrointestinal disorders. Its unique gel-forming properties can help alleviate symptoms related to conditions such as gastroesophageal reflux disease (GERD) and ulcerative colitis. Sodium alginate works by forming a viscous gel that coats the stomach lining, thereby reducing acid reflux and protecting against irritation. The growing prevalence of gastrointestinal disorders worldwide is driving demand for effective, natural treatment options, fostering the adoption of sodium alginate-based therapies. As healthcare providers seek innovative solutions to improve patient outcomes, the application of sodium alginate in gastrointestinal health is expected to witness substantial growth, marking it as a critical sector in the market.

By Distribution Channel

Hospitals :

Hospitals represent a crucial distribution channel for medical grade sodium alginate products, primarily due to their extensive utilization in wound care, surgical procedures, and various therapeutic applications. The presence of advanced medical facilities and healthcare professionals in hospitals ensures a steady demand for high-quality sodium alginate products. Hospitals are increasingly adopting modern treatment protocols that incorporate biocompatible materials for effective patient care, contributing to the growth of sodium alginate usage. Furthermore, hospital pharmacies often stock sodium alginate products, ensuring accessibility for medical professionals. The rising incidence of chronic wounds and surgical procedures is anticipated to drive the demand for sodium alginate in hospitals, solidifying their role as a key distribution channel in the market.

Clinics :

Clinics play a significant role in the distribution of medical grade sodium alginate products, catering to patients with specific needs in wound care, dental services, and other therapeutic areas. Many outpatient clinics, including dermatology and dental clinics, utilize sodium alginate for its versatile applications. The growing emphasis on preventative healthcare and outpatient services is driving demand for sodium alginate products in clinics. The ability of clinics to provide personalized care and treatment options enhances the appeal of sodium alginate in these settings. As more patients seek accessible healthcare solutions, the importance of clinics in the sodium alginate distribution landscape is expected to grow, contributing to overall market expansion.

Online Stores :

The rise of e-commerce has transformed the medical supply landscape, with online stores becoming an increasingly popular distribution channel for medical grade sodium alginate products. The convenience of online shopping allows healthcare providers and patients to access various sodium alginate products with ease, driving demand in this channel. Online platforms often provide detailed product information, reviews, and competitive pricing, which can influence purchasing decisions. Additionally, the growing trend towards digital health solutions has prompted manufacturers to invest in online sales channels, further enhancing market accessibility. As the global shift towards e-commerce continues, the online store segment is anticipated to experience significant growth, driven by the need for convenience and efficiency in purchasing medical supplies.

Retail Pharmacies :

Retail pharmacies play a vital role in the distribution of medical grade sodium alginate products, providing accessible solutions for patients seeking over-the-counter options for wound care and gastrointestinal health. Many retail pharmacies stock sodium alginate-based products, such as wound dressings and gastrointestinal gels, catering to a broad consumer base. The increasing awareness of the benefits of natural products and the growing trend of self-care are driving demand for sodium alginate in retail settings. Furthermore, as pharmacies expand their offerings to include more specialized health products, the market for sodium alginate in retail pharmacies is expected to grow. This segment's convenience and accessibility are crucial for consumers, solidifying retail pharmacies' role in the sodium alginate distribution landscape.

By Ingredient Type

High G :

High G sodium alginate, characterized by its high guluronic acid content, has unique properties that make it suitable for various biomedical applications. This ingredient type is particularly valued for its gelation ability in the presence of calcium ions, allowing for the formation of robust and stable gels. High G sodium alginate is commonly used in wound dressings, where its gel-forming capabilities can provide a protective barrier and promote an optimal healing environment. The demand for High G sodium alginate is expected to rise as healthcare professionals seek effective materials for advanced wound care solutions. Furthermore, its potential applications in controlled drug delivery systems are expected to expand, making High G sodium alginate a significant player in the medical grade sodium alginate market.

High M :

High M sodium alginate, featuring a high content of mannuronic acid, is known for its unique properties, such as forming soft and pliable gels. This ingredient type is ideal for applications requiring flexibility and comfort, making it a popular choice in dental impressions and soft tissue engineering. High M sodium alginate's ability to capture fine details is particularly beneficial in dental settings, where precision is essential. Additionally, its biocompatibility makes it suitable for various biomedical applications, enhancing its attractiveness in tissue engineering and regenerative medicine. The growing focus on patient comfort and effective treatment options is expected to drive demand for High M sodium alginate in the market, solidifying its role in the medical grade sodium alginate landscape.

High VG :

High VG sodium alginate is distinguished by its high viscosity and gel strength, making it suitable for a range of medical applications, particularly in the formulation of controlled-release drug delivery systems. This ingredient type is valued for its ability to form stable gels, allowing for prolonged therapeutic effects and enhanced patient compliance. The growing interest in innovative drug delivery solutions is anticipated to increase the demand for High VG sodium alginate in the pharmaceutical industry. Additionally, its applications extend to wound dressings and tissue engineering, where its mechanical properties can support healing processes and cellular growth. The versatility and effectiveness of High VG sodium alginate position it as a key component in advancing medical technologies and enhancing patient care.

By Region

The regional analysis of the medical grade sodium alginate market reveals significant insights into the growth prospects across various geographical areas. North America is expected to dominate the market due to its advanced healthcare infrastructure, high healthcare expenditure, and the presence of key players in the medical-grade sodium alginate industry. The United States, in particular, is anticipated to witness a steady increase in demand for sodium alginate products, driven by the growing prevalence of chronic wounds and the expansion of outpatient care services. The North American market is projected to grow at a CAGR of 6.7% during the forecast period, highlighting the region's commitment to adopting innovative medical solutions.

Europe is also poised for substantial growth in the medical grade sodium alginate market, attributed to the rising focus on wound care management and advancements in tissue engineering. Countries such as Germany, France, and the United Kingdom are embracing biocompatible materials for various medical applications, driving demand for sodium alginate products. The increasing number of surgical procedures and the aging population in these regions contribute to the market's expansion. Furthermore, the Asia Pacific region is expected to emerge as a key player in the coming years, fueled by the growing healthcare sector and investments in medical research. The overall regional growth trends indicate a promising outlook for the medical grade sodium alginate market, aligning with the global increase in demand for effective healthcare solutions.

Opportunities

The medical grade sodium alginate market presents numerous opportunities for growth, particularly in the areas of research and innovation. As researchers explore new applications and formulations of sodium alginate, the potential for its use in emerging fields, such as personalized medicine and regenerative therapies, is expanding. Companies investing in R&D to develop novel sodium alginate-based products tailored to specific medical needs are likely to gain a competitive edge in the market. Furthermore, as healthcare professionals increasingly recognize the benefits of biocompatible materials, the demand for medical grade sodium alginate is expected to rise significantly. The opportunity to collaborate with academic institutions and research organizations to advance the understanding and applications of sodium alginate presents an avenue for businesses to enhance their product offerings and meet the evolving needs of the healthcare industry.

Additionally, the increasing trend towards preventive healthcare and the growing awareness of the importance of wound care management present substantial opportunities for the market. As patients become more informed about available treatment options, the demand for effective and reliable medical solutions becomes paramount. Companies that focus on educating healthcare professionals and patients about the advantages of medical grade sodium alginate products are likely to see an uptick in adoption. Moreover, as e-commerce continues to reshape the medical supply landscape, companies that establish a strong online presence and enhance accessibility to sodium alginate products can capitalize on this growing trend, further expanding their market reach and boosting sales.

Threats

Despite the promising growth prospects in the medical grade sodium alginate market, several threats could hinder its expansion. One of the primary concerns is the increasing competition from alternative biomaterials that offer similar benefits, such as hydrocolloids and synthetic polymers. As new materials continue to emerge in the healthcare sector, the market share for sodium alginate may be affected, necessitating continuous innovation and product development to maintain relevance. Additionally, fluctuations in the supply chain and raw material availability could impact the production and pricing of sodium alginate products. Companies must be vigilant in managing their supply chains to mitigate potential disruptions that could affect their operational efficiency and market competitiveness.

Another significant threat to the medical grade sodium alginate market is the stringent regulatory environment surrounding the approval and commercialization of medical products. Compliance with various international regulations can pose challenges for manufacturers, particularly those looking to enter new markets or launch innovative products. The lengthy approval processes and associated costs may deter some companies from pursuing new developments, limiting the overall growth of the market. Moreover, the risk of product recalls due to safety concerns can negatively impact brand reputation and customer trust, further complicating the market landscape. Addressing these threats will require strategic planning and a focus on quality assurance to ensure that sodium alginate products continue to meet the needs and expectations of healthcare providers and patients alike.

Competitor Outlook

• DuPont
• KIMICA Corporation
• Santamaría
• Alginates Australia
• BioCare Copenhagen
• Hyaluronic Acid Products
• Meron Medical
• Nantong Aoyu Biotech
• Seaspring Chemical
• Gelymar S.A.
• Shakespeare Biochem
• Mazda Chemicals
• Gelettos
• Shandong Jintai International Trade
• FMC Corporation

The competitive landscape of the medical grade sodium alginate market is characterized by the presence of numerous players, ranging from established multinational corporations to emerging regional companies. Key players are focusing on strategic partnerships, mergers, and acquisitions to enhance their product offerings and expand their market reach. Additionally, companies are investing in research and development to innovate new applications and formulations of sodium alginate to cater to the evolving needs of the healthcare industry. The competition is intensifying as businesses strive to differentiate themselves through quality, product performance, and customer service.

Major companies such as DuPont and FMC Corporation are at the forefront of the market, leveraging their extensive experience and resources to develop cutting-edge sodium alginate products. DuPont, known for its commitment to sustainability and innovation, is focusing on creating biocompatible materials that meet the highest quality standards. FMC Corporation, with its robust portfolio of specialty chemicals, is dedicated to advancing the applications of sodium alginate in various medical fields, including wound care and drug delivery systems. These industry leaders play a crucial role in shaping the market and driving advancements in sodium alginate technology.

Emerging players, such as KIMICA Corporation and Alginates Australia, are also making significant strides in the market by capitalizing on niche applications and regional demand. KIMICA Corporation, for instance, specializes in producing high-quality sodium alginate for dental and pharmaceutical applications, positioning itself as a trusted supplier in those sectors. Alginates Australia emphasizes sustainable sourcing and production methods, appealing to environmentally conscious consumers and healthcare providers. Together, these companies contribute to a dynamic and competitive market landscape, fostering innovation and growth in the medical grade sodium alginate sector.

• 1 Appendix

  • 1.1 List of Tables
  • 1.2 List of Figures

• 2 Introduction

  • 2.1 Market Definition
  • 2.2 Scope of the Report
  • 2.3 Study Assumptions
  • 2.4 Base Currency & Forecast Periods

• 3 Market Dynamics

  • 3.1 Market Growth Factors
  • 3.2 Economic & Global Events
  • 3.3 Innovation Trends
  • 3.4 Supply Chain Analysis

• 4 Consumer Behavior

  • 4.1 Market Trends
  • 4.2 Pricing Analysis
  • 4.3 Buyer Insights

• 5 Key Player Profiles

  • 5.1 DuPont
    • 5.1.1 Business Overview
    • 5.1.2 Products & Services
    • 5.1.3 Financials
    • 5.1.4 Recent Developments
    • 5.1.5 SWOT Analysis
  • 5.2 Gelettos
    • 5.2.1 Business Overview
    • 5.2.2 Products & Services
    • 5.2.3 Financials
    • 5.2.4 Recent Developments
    • 5.2.5 SWOT Analysis
  • 5.3 Gelymar S.A.
    • 5.3.1 Business Overview
    • 5.3.2 Products & Services
    • 5.3.3 Financials
    • 5.3.4 Recent Developments
    • 5.3.5 SWOT Analysis
  • 5.4 Meron Medical
    • 5.4.1 Business Overview
    • 5.4.2 Products & Services
    • 5.4.3 Financials
    • 5.4.4 Recent Developments
    • 5.4.5 SWOT Analysis
  • 5.5 FMC Corporation
    • 5.5.1 Business Overview
    • 5.5.2 Products & Services
    • 5.5.3 Financials
    • 5.5.4 Recent Developments
    • 5.5.5 SWOT Analysis
  • 5.6 Mazda Chemicals
    • 5.6.1 Business Overview
    • 5.6.2 Products & Services
    • 5.6.3 Financials
    • 5.6.4 Recent Developments
    • 5.6.5 SWOT Analysis
  • 5.7 Santamaría
    • 5.7.1 Business Overview
    • 5.7.2 Products & Services
    • 5.7.3 Financials
    • 5.7.4 Recent Developments
    • 5.7.5 SWOT Analysis
  • 5.8 BioCare Copenhagen
    • 5.8.1 Business Overview
    • 5.8.2 Products & Services
    • 5.8.3 Financials
    • 5.8.4 Recent Developments
    • 5.8.5 SWOT Analysis
  • 5.9 KIMICA Corporation
    • 5.9.1 Business Overview
    • 5.9.2 Products & Services
    • 5.9.3 Financials
    • 5.9.4 Recent Developments
    • 5.9.5 SWOT Analysis
  • 5.10 Seaspring Chemical
    • 5.10.1 Business Overview
    • 5.10.2 Products & Services
    • 5.10.3 Financials
    • 5.10.4 Recent Developments
    • 5.10.5 SWOT Analysis
  • 5.11 Alginates Australia
    • 5.11.1 Business Overview
    • 5.11.2 Products & Services
    • 5.11.3 Financials
    • 5.11.4 Recent Developments
    • 5.11.5 SWOT Analysis
  • 5.12 Shakespeare Biochem
    • 5.12.1 Business Overview
    • 5.12.2 Products & Services
    • 5.12.3 Financials
    • 5.12.4 Recent Developments
    • 5.12.5 SWOT Analysis
  • 5.13 Nantong Aoyu Biotech
    • 5.13.1 Business Overview
    • 5.13.2 Products & Services
    • 5.13.3 Financials
    • 5.13.4 Recent Developments
    • 5.13.5 SWOT Analysis
  • 5.14 Hyaluronic Acid Products
    • 5.14.1 Business Overview
    • 5.14.2 Products & Services
    • 5.14.3 Financials
    • 5.14.4 Recent Developments
    • 5.14.5 SWOT Analysis
  • 5.15 Shandong Jintai International Trade
    • 5.15.1 Business Overview
    • 5.15.2 Products & Services
    • 5.15.3 Financials
    • 5.15.4 Recent Developments
    • 5.15.5 SWOT Analysis

• 6 Market Segmentation

  • 6.1 Medical Grade Sodium Alginate Market, By Application
    • 6.1.1 Wound Dressings
    • 6.1.2 Dental Impressions
    • 6.1.3 Controlled Release Drug Delivery Systems
    • 6.1.4 Tissue Engineering
    • 6.1.5 Gastrointestinal Disorders
  • 6.2 Medical Grade Sodium Alginate Market, By Product Type
    • 6.2.1 Powder
    • 6.2.2 Granules
    • 6.2.3 Gel
  • 6.3 Medical Grade Sodium Alginate Market, By Ingredient Type
    • 6.3.1 High G
    • 6.3.2 High M
    • 6.3.3 High VG
  • 6.4 Medical Grade Sodium Alginate Market, By Distribution Channel
    • 6.4.1 Hospitals
    • 6.4.2 Clinics
    • 6.4.3 Online Stores
    • 6.4.4 Retail Pharmacies

• 7 Competitive Analysis

  • 7.1 Key Player Comparison
  • 7.2 Market Share Analysis
  • 7.3 Investment Trends
  • 7.4 SWOT Analysis

• 8 Research Methodology

  • 8.1 Analysis Design
  • 8.2 Research Phases
  • 8.3 Study Timeline

• 9 Future Market Outlook

  • 9.1 Growth Forecast
  • 9.2 Market Evolution

• 10 Geographical Overview

  • 10.1 Europe - Market Analysis
    • 10.1.1 By Country
      • 10.1.1.1 UK
      • 10.1.1.2 France
      • 10.1.1.3 Germany
      • 10.1.1.4 Spain
      • 10.1.1.5 Italy
  • 10.2 Asia Pacific - Market Analysis
    • 10.2.1 By Country
      • 10.2.1.1 India
      • 10.2.1.2 China
      • 10.2.1.3 Japan
      • 10.2.1.4 South Korea
  • 10.3 Latin America - Market Analysis
    • 10.3.1 By Country
      • 10.3.1.1 Brazil
      • 10.3.1.2 Argentina
      • 10.3.1.3 Mexico
  • 10.4 North America - Market Analysis
    • 10.4.1 By Country
      • 10.4.1.1 USA
      • 10.4.1.2 Canada
  • 10.5 Middle East & Africa - Market Analysis
    • 10.5.1 By Country
      • 10.5.1.1 Middle East
      • 10.5.1.2 Africa
  • 10.6 Medical Grade Sodium Alginate Market by Region

• 11 Global Economic Factors

  • 11.1 Inflation Impact
  • 11.2 Trade Policies

• 12 Technology & Innovation

  • 12.1 Emerging Technologies
  • 12.2 AI & Digital Trends
  • 12.3 Patent Research

• 13 Investment & Market Growth

  • 13.1 Funding Trends
  • 13.2 Future Market Projections

• 14 Market Overview & Key Insights

  • 14.1 Executive Summary
  • 14.2 Key Trends
  • 14.3 Market Challenges
  • 14.4 Regulatory Landscape

Segments Analyzed in the Report

The global Medical Grade Sodium Alginate market is categorized based on

By Product Type

• Powder
• Granules
• Gel

By Application

• Wound Dressings
• Dental Impressions
• Controlled Release Drug Delivery Systems
• Tissue Engineering
• Gastrointestinal Disorders

By Distribution Channel

• Hospitals
• Clinics
• Online Stores
• Retail Pharmacies

By Ingredient Type

• High G
• High M
• High VG

By Region

• North America
• Europe
• Asia Pacific
• Latin America
• Middle East & Africa

Key Players

• DuPont
• KIMICA Corporation
• Santamaría
• Alginates Australia
• BioCare Copenhagen
• Hyaluronic Acid Products
• Meron Medical
• Nantong Aoyu Biotech
• Seaspring Chemical
• Gelymar S.A.
• Shakespeare Biochem
• Mazda Chemicals
• Gelettos
• Shandong Jintai International Trade
• FMC Corporation