Pharma

Dal settore farmaceutico al settore dei dispositivi medici, sino al settore alimentare, la caratterizzazione degli Extractables (E) e dei Leachables (L) è un aspetto importante di qualità del prodotto.

Gli Extractables e i Leachables sono definiti in USP nel seguente modo:

 

Extractables:

Organic and inorganic chemical entities that are released from a pharmaceutical packaging/delivery system, packaging component, or packaging material of construction and into an extraction solvent under laboratory conditions.

 

Leachables:

Foreign organic and inorganic chemical entities that are present in a packaged drug product because they have leached into the packaged drug product from a packaging/delivery system, packaging component, or packaging material of construction under normal conditions of storage and use or during accelerated drug product stability studies.

 

Oltre alle potenziali fonti di E&L riportate nelle definizioni, è opportuno ricordare che tale tipologia di valutazione viene effettuata anche su componenti di processo (ad es. filtri) e sul packaging primario destinato a contenere gli intermedi di sintesi in fase liquida.

Tenendo bene a mente che le sostanze rilasciabili presenti in un prodotto finito possono modificare e alterare la stabilità del prodotto, nonché la sua efficacia, ma soprattutto possono rappresentare un pericolo per il paziente, un accurato controllo e una accurata valutazione degli E&L sono indispensabili.

 

Valutazione e controllo:

Ad oggi, in campo farmaceutico, non è disponibile una linea guida armonizzata a livello internazionale atta a valutare e controllare gli Extractables e i Leachables.

Anche se ICH ha sviluppato specifiche linee guida per la gestione e valutazione delle impurezze, quali ICH Q3A, Q3B, Q3C, Q3D e M7, gli E&L sono esclusi dall’ambito di applicazione di queste ultime.

Questa lacuna e la mancanza di chiarezza riguardo alla gestione degli E&L, ha generato nel corso degli anni incertezza e interpretazioni variabili. Questa situazione può comportare ritardi nell’accesso ai medicinali da parte dei pazienti.

Pertanto, nell’estate 2020, ICH ha rilasciato un concept paper per la proposta di linea guida ICH Q3E, specifica per gli E&L. Questa guida intende includere i prodotti chimici e biologici, compresi i prodotti di combinazione farmaco-dispositivo, ma non i dispositivi medici.

Finalità della nuova linea guida ICH sarà fornire:

– un allineamento all’interno dei documenti guida ICH; l’armonizzazione delle soglie e delle valutazioni di sicurezza; opzioni di controllo per la mitigazione del rischio; la conduzione di studi E&L; la progettazione di una strategia di controllo E&L basata su principi scientifici e basati sul rischio; processi per affrontare la selezione e la caratterizzazione di materiali e componenti; la valutazione del rischio e la gestione del ciclo di vita per i sistemi di chiusura dei contenitori, i sistemi di produzione e i componenti dei dispositivi di somministrazione dei farmaci.

 

Fraunhofer ITEM leading an EMA-funded research project

 

Nitrosamines (NAs) are a class of organic chemical compounds that humans may be exposed to by tobacco smoking or consuming certain foods. N-nitrosamines have been classified as probable human carcinogens and are categorized in the ICH M7 guideline as belonging to the “cohort of concern” group of high-potency mutagenic carcinogens. Some active pharmaceutical ingredients (APIs) carry NAs as impurities from production and/or storage or may cause their formation in the gastrointestinal tract.

A joint research project funded by the European Medicines Agency (EMA) and led by Fraunhofer ITEM will shed light on the mutagenicity of different classes of NAs to distinguish highly potent from less potent carcinogens. Besides classical nitrosamine structures, API-like nitrosamine derivatives will also be investigated. It will be of particular importance to look for their ability to undergo metabolic activation and to form different DNA adducts. Additionally, corresponding DNA repair mechanisms will be addressed for the first time. By developing novel in-silico as well as in-vitro test systems, the consortium aims to improve risk assessment and to derive reference doses such as acceptable intake (AI) values.

Initially, the focus will be placed on nitrosamine metabolites and their potential to damage DNA when not adequately repaired. The obtained data will be used to correlate the structure of NAs to their potential toxic/mutagenic effects. By means of a quantitative structure-activity relationships (QSAR) approach, this will allow derivation of acceptable intake values for compounds lacking appropriate in-vivo cancer studies, i.e. following a read-across approach.

Secondly, the effect of the physiological environment of the gastrointestinal tract (including the microbiome) on the formation of NAs from drugs or their degradation products will be studied. Due to the lack of knowledge about endogenous nitrosamine formation, it is of utmost importance to elucidate potential mechanisms in order to reduce the carcinogenic risks for patients. Research findings of these laboratory studies will be integrated and generalized in order to develop predictive QSAR models for the susceptibility of drugs to be nitrosated.

Finally, current bacterial mutagenicity test systems as well as novel in-vitro genotoxicity tests, such as the comet assay in liver cell models (primary human and rat hepatocytes, human liver cell lines), will be evaluated, optimized and validated. Metabolic competence will represent one key topic, to reach the final aim of reliably detecting mutagenicity of different NAs.

 

 

Source:

https://www.item.fraunhofer.de/en/press-and-media/press-releases/mutagenicity-of-nitrosamines.html

The context

 

Nitrosamines have become a focus of global regulatory agencies, including FDA, due to the discovery of trace amounts of these compounds in a class of drugs known as angiotensin II receptor blockers (ARB), frequently referred to as “sartans.” The “sartan” molecules involved include valsartan, losartan, irbesartan, azilsartan, olmesartan, eprosartan, candesartan, and telmisartan. Valsartan and losartan were the most severely affected due to their market share when several lots were recalled.

The genotoxic and carcinogenic potential of N-nitrosamines raises a serious safety concern, and in September 2020, the FDA issued guidance for the pharmaceutical industry regarding the control of nitrosamines in drug products.

The FDA database shows that >1400 product lots have been recalled from the market due to the presence of carcinogenic N-nitrosamine impurities at levels beyond the acceptable intake limit of 26.5 ng/day. The drugs that were present in recalled products include valsartan, irbesartan, losartan, metformin, ranitidine, and nizatidine. This perspective provides a critical account of these product recalls with an emphasis on the source and mechanism for the formation of N-nitrosamines in these products.

Many of the global regulatory authorities, including WHO, EMA and Health Canada have provided directives regarding evaluation of nitrosamines in products including complete retrospective analysis of all approved Drug Products (DPs) based on the strong concern of possible carcinogenicity effects on exposed patients and to mitigate such an effect.

Very recently, in February 2021, FDA release a draft guidance for Industry: Click here for the original document

The FDA Guidance for Industry gives suggestion to the industry on how to approach the assessment of the nitrosamine in drug active and drug products including some indication of acceptable limits for some of them as in the following figure:

Recommendation to API manufactures and to Drug Products manufacturers are included to mitigate the impact of nitrosamine impurities in drugs as well as how to control the drug supply chain and how to report changes to reduce their presence.

Since some years, Pharmaceutical Industry activated itself to study such a problem from an analytical point of view and provide toxicological assessment to reach possible acceptable level of nitrosamine species in a variety of drug product.

The industry proposes a streamlined approach to reduce the presence of nitrosamines in their Drug Products is based on better understanding of the source of these impurities. The risk evaluation will take into account all aspects of the development of the DPs throughout its life cycle.

Five sources of nitrosamines formation have been identified:

  • presence of certain process condition and certain raw materials, starting material and intermediates with lack of complete purging methods to avoid the contamination;
  • the use of sodium nitrite or other nitrites in presence of secondary and tertiary amines. They can be present in solvent and reagents or in common bass such as triethylamine;
  • the use of contaminated raw materials such us in the manufacturing process such as recycled solvents, reagents and catalyst that can pose a risk due to the presence of amines in the waste stream;
  • Using third parties to recover the materials (again solvents, reagents and catalysts) which are not addressed to pose attention to the contamination matter and do not use appropriate dedicated equipment;
  • the use of contaminated starting materials including intermediates from providers using chemical processes which produce nitrosamines.

The risk-based approach adopted by pharmaceutical industry is addressed to understand the chemical source of nitrosamines by evaluating the chemical process to manufacture the API (Active Pharmaceutical Ingredients) and any possible co-formulants.

This implies several focused evaluations:

  • a complete analysis of the supply chain/s;
  • a complete analysis of the chemical manufacturing processes;
  • a complete evaluation of the Drug Product, its storage condition, and possible degradation products and consequent reaction products when approaching the nitrosamine contamination in the final DP;
  • the development of suitable analytical methods to detect nitrosamines species with determination of a suitable LOD (Limit of Detection) and LOQ (Limit of Quantification) in correlation with the acceptable limits or absence of nitrosamine in API and DPs.

The discussion at the scientific and regulatory level is never-ending with particular reference to the setting of suitable analytical methods and to understand the huge chemical processes and cross-formation processes which lead to nitrosamines presence and, of course, setting of related acceptable limits.