Application of immunocapture and nanoflow LC-MS/MS to overcome the barriers to the quantitation of oxytocin in plasma of women in third stage labour.

AIMS: Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. To prevent PPH, the WHO recommends administration of oxytocin (OT) immediately after birth, i.e. during the third stage of labour (TSL). Previous studies demonstrate that methods to quantify OT in biological matrices, e.g. enzyme-linked immunosorbent assays (ELISA), radioimmunoassays (RIA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) lack the specificity and/or sensitivity to accurately quantify OT in plasma from women administered OT during TSL. This is due to increased metabolic clearance of OT in late-stage pregnancy and at the time of childbirth, resulting in extremely low OT plasma concentrations. This study describes the development of an ultra-sensitive bioanalytical method that overcomes the issues previously reported and enables accurate pharmacokinetic analyses of exogenously administered OT in TSL. METHODS: A selective and sensitive assay to quantify OT in TSL plasma was developed. Immunoprecipitation (IP) was applied to selectively extract OT from the TSL plasma, thereby generating clean extracts compatible with nanoflow LC (nLC). nLC-MS/MS was chosen for its high sensitivity and ability to differentiate between OT and potentially co-captured OT-like immunoreactive products. RESULTS: The presented methodology is accurate and precise, with a good linear fit between 100-10 000 fg mL-1 OT. TSL plasma samples from a clinical phase 1 study (NCT02999100) were analysed successfully, enabling OT quantification down to 100 fg mL-1. CONCLUSIONS: The presented IP-nLC-MS/MS method succeeded in overcoming the sensitivity challenge related to the assay of OT in TSL plasma and thereby revealing the PK profiles of OT in TSL plasma clinical study samples.

The quality of medicines for the prevention and management of hypertensive disorders of pregnancy: A systematic review.

The quality of medicines for the prevention and management of hypertensive disorders of pregnancy globally is a critical challenge in the reduction of maternal mortality rate. We aimed to conduct a systematic review of available studies on the quality of the eight medicines recommended globally for the prevention and management of hypertensive disorders of pregnancy. We searched five electronic databases- Ovid MEDLINE, EMBASE, CINAHL, ProQuest and Cochrane Library, and also grey literature, without year or language limitations. Any study assessing the quality parameters (Active Pharmaceutical Ingredients, pH, sterility, solubility, impurities) of medicines by using any valid laboratory methods was eligible. Two reviewers independently screened the studies, extracted data and applied Medicine Quality Assessment Reporting Guidelines tool for quality assessment. Results were narratively reported and stratified by the drug types. Of 5669 citations screened, 33 studies from 27 countries were included. Five studies reported on the quality of magnesium sulphate-two (Nigeria and USA) found substandard medicine due to failing API specification and contaminants, respectively. Another study from Nigeria and a multi-country study (10 lower-middle- and low-income countries) found poor-quality due to failing the pH criteria. Seven of eight studies evaluating aspirin found quality issues, including degraded medicines in five studies (Brazil, USA, Yugoslavia and Pakistan). Five studies of calcium supplements found quality issues, particularly heavy metal contamination. Of 15 antihypertensives quality studies, 12 found substandard medicines and one study identified counterfeit medicines. This systematic review identified pervasive issues of poor-quality medicines across all recommended medicines used to prevent or treat hypertensive disorders of pregnancy, raising concerns regarding their safety and effectiveness.

Exploring the role of ex vivo metabolism on blood and plasma measurements of oxytocin among women in the third stage of labour: A post hoc study.

AIMS: To examine the role of ex vivo oxytocin metabolism in post-dose peptide measurements. METHODS: The stability of oxytocin (Study 1) and oxytocinase activity (Study 2) in late-stage pregnancy blood was quantified using liquid-chromatography tandem mass-spectrometry (LC-MS/MS) and a fluorogenic assay, respectively. Analyses were conducted using blood from pregnant women (>36 weeks gestation) evaluated in lithium heparin (LH), ethylenediaminetetraacetic acid (EDTA) and BD P100 blood collection tubes with or without protease inhibitors. In addition, plasma oxytocin concentrations following administration of oxytocin 240 IU inhaled, 5 IU intravenous or 10 IU intramuscular in women in third stage of labour (TSL) were analysed using enzyme-linked immunosorbent assay (ELISA) and LC-MS/MS to understand how quantified peptide concentrations differ between these analytical methods (Study 3). RESULTS: Study 1: Oxytocin was stable in blood collected into EDTA tubes with or without protease inhibitors but not in LH tubes. Study 2: Blood collected into all EDTA-containing collection tubes led to near-complete inhibition of oxytocinase (≤100 min). In plasma, a 35% reduction in oxytocinase activity was observed in LH tubes with EDTA added. In plasma from late-stage pregnancy compared to nonpregnant participants, the oxytocinase activity was approximately 11-fold higher. Study 3: Plasma oxytocin concentrations from nonpregnant or women in TSL following exogenous oxytocin administration were ≤33 times higher when analysed using ELISA vs. LC-MS/MS methods. CONCLUSIONS: Collection of blood from late-stage pregnant women into tubes containing EDTA inhibits oxytocinase effectively stabilizing oxytocin, suggesting low concentrations of oxytocin after dose administration reflect rapid in vivo metabolism.

Pharmacokinetics and safety of inhaled oxytocin compared with intramuscular oxytocin in women in the third stage of labour: A randomized open-label study.

AIMS: To compare pharmacokinetics (PK) and safety of heat-stable inhaled (IH) oxytocin with intramuscular (IM) oxytocin in women in third stage of labour (TSL), the primary endpoint being PK profiles of oxytocin IH and secondary endpoint of safety. METHODS: A phase 1, randomized, cross-over study was undertaken in 2 UK and 1 Australian centres. Subjects were recruited into 2 groups: Group 1, women in TSL; Group 2, nonpregnant women of childbearing potential (Cohort A, combined oral contraception; Cohort B, nonhormonal contraception). Participants were randomized 1:1 to: Group 1, oxytocin 10 IU (17 µg) IM or oxytocin 240 IU (400 µg) IH immediately after delivery; Group 2, oxytocin 5 IU (8.5 µg) intravenously and oxytocin 240 IU (400 µg) IH at 2 separate dosing sessions. RESULTS: Participants were recruited between 23 November 2016 to 4 March 2019. In Group 1, 17 participants were randomized; received either IH (n = 9) or IM (n = 8) oxytocin. After IH and IM administration, most plasma oxytocin concentrations were below quantification limits (2 pg/mL). In Group 2 (n = 14), oxytocin IH concentrations remained quantifiable ≤3 h postdose. Adverse events were reported in both groups, with no deaths reported: Group 1, IH n = 3 (33%) and IM n = 2 (25%); Group 2, n = 14 (100%). CONCLUSION: Safety profiles of oxytocin IH and IM were similar. However, PK profiles could not be established for oxytocin IH or IM in women in TSL, despite using a highly sensitive and specific assay.

The compatibility of oxytocin and tranexamic acid injection products when mixed for co-administration by infusion for the treatment of postpartum haemorrhage: An in vitro investigation.

OBJECTIVE: To investigate the compatibility of oxytocin and tranexamic acid injection products when mixed for the purpose of co-administration by intravenous infusion. DESIGN: Compatibility testing. SETTING: Hospitals taking part in a multicentre postpartum haemorrhage treatment (E-MOTIVE) trial in Kenya, Nigeria, Tanzania and South Africa. SAMPLE: Oxytocin and tranexamic acid products. METHODS: The compatibility of two sentinel products of oxytocin injection and tranexamic acid injection in 200-mL infusion bags of both 0.9% w/v saline and Ringer's lactate solution was assessed. We analysed all tranexamic acid-oxytocin combinations, and each evaluation was conducted for up to 3 h. Subsequently, the compatibility of multiple tranexamic acid products with reference oxytocin products when mixed in 0.9% w/v saline over a period of 1 h was investigated. MAIN OUTCOME MEASURES: Concentration of oxytocin over time after mixing with tranexamic acid products. RESULTS: We found significant interaction between certain oxytocin and tranexamic acid products after mixing them in vitro and observing for 1 h. The interaction substantially impacted oxytocin content leading to reduction in concentration (14.8%-29.0%) immediately on mixing (t = 0 min). In some combinations, the concentration continued to decline throughout the stability assessment period. Oxytocin loss was observed in 7 out of 22 (32%) of combinations tested. CONCLUSIONS: In a clinical setting, mixing certain oxytocin and tranexamic acid products before administration may result in an underdosing of oxytocin, compromising care in an emergency life-threatening situation. The mixing of oxytocin and tranexamic acid injection products for co-administration with intravenous infusion fluids should be avoided until the exact nature of the observed interaction and its implications are understood.

Drug repurposing using real-world data.

The use of real-world data in drug repurposing has emerged due to well-established advantages of drug repurposing in supplementing de novo drug discovery and incentives in incorporating real-world evidence in regulatory approvals. We conducted a scoping review to characterize repurposing studies using real-world data and discuss their potential challenges and solutions. A total of 250 studies met the inclusion criteria, of which 36 were original studies on hypothesis generation, 101 on hypothesis validation, and seven on safety assessment. Key challenges that should be addressed for future progress in using real-world data for repurposing include isolated data sources with poor clinical granularity, false-positive signals from data mining, the sensitivity of hypothesis validation to bias and confounding, and the lack of clear regulatory guidance.

Quality of oxytocin and tranexamic acid for the prevention and treatment of postpartum hemorrhage in Kenya, Nigeria, South Africa, and Tanzania.

OBJECTIVE: To check the quality of oxytocin and tranexamic acid-two recommended products for prevention and treatment of postpartum hemorrhage (PPH)-used in facilities taking part in an implementation research project to improve PPH diagnosis and management. METHODS: Between September 2020 and August 2021, oxytocin and tranexamic acid products used in the study facilities in Kenya, Nigeria, South Africa, and Tanzania were collected and transported in cold storage for analysis. Samples were analyzed according to the International (oxytocin) and British Pharmacopeia (tranexamic acid) standards. RESULTS: Of the 17 unique oxytocin products, 33 individual measurements were made. Only six unique products had adequate content and no related substances exceeding the recommended limits. Of 14 tranexamic acid samples, 10 showed adequate content. One product in Kenya and two products in Nigeria from different manufacturers had a high content of related substances, which classified them as substandard. CONCLUSION: While we were unable to investigate the origin regarding poor manufacturing or poor storage or both, the high number of substandard oxytocin samples is of great concern. Most of the tranexamic acid samples had adequate content but the presence of impurities in multiple products is worrying and requires further study.

Cost-effectiveness of inhaled oxytocin for prevention of postpartum haemorrhage: a modelling study applied to two high burden settings.

BACKGROUND: Access to oxytocin for prevention of postpartum haemorrhage (PPH) in resource-poor settings is limited by the requirement for a consistent cold chain and for a skilled attendant to administer the injection. To overcome these barriers, heat-stable, non-injectable formulations of oxytocin are under development, including oxytocin for inhalation. This study modelled the cost-effectiveness of an inhaled oxytocin product (IHO) in Bangladesh and Ethiopia. METHODS: A decision analytic model was developed to assess the cost-effectiveness of IHO for the prevention of PPH compared to the standard of care in Bangladesh and Ethiopia. In Bangladesh, introduction of IHO was modelled in all public facilities and home deliveries with or without a skilled attendant. In Ethiopia, IHO was modelled in all public facilities and home deliveries with health extension workers. Costs (costs of introduction, PPH prevention and PPH treatment) and effects (PPH cases averted, deaths averted) were modelled over a 12-month program. Life years gained were modelled over a lifetime horizon (discounted at 3%). Cost of maintaining the cold chain or effects of compromised oxytocin quality (in the absence of a cold chain) were not modelled. RESULTS: In Bangladesh, IHO was estimated to avert 18,644 cases of PPH, 76 maternal deaths and 1954 maternal life years lost. This also yielded a cost-saving, with the majority of gains occurring among home deliveries where IHO would replace misoprostol. In Ethiopia, IHO averted 3111 PPH cases, 30 maternal deaths and 767 maternal life years lost. The full IHO introduction program bears an incremental cost-effectiveness ratio (ICER) of between 2 and 3 times the per-capita Gross Domestic Product (GDP) ($1880 USD per maternal life year lost) and thus is unlikely to be considered cost-effective in Ethiopia. However, the ICER of routine IHO administration considering recurring cost alone falls under 25% of per-capita GDP ($175 USD per maternal life-year saved). CONCLUSIONS: IHO has the potential to expand access to uterotonics and reduce PPH-associated morbidity and mortality in high burden settings. This can facilitate reduced spending on PPH management, making the product highly cost-effective in settings where coverage of institutional delivery is lagging.

Qualitative formative implementation research to inform introduction of a new essential medicine.

BACKGROUND: The launch of novel pharmaceuticals in the developing world faces significant barriers that can delay or ultimately inhibit uptake. Implementation research can provide an understanding of factors influencing the introduction and scale up of a new product and thus can inform implementation strategy development. OBJECTIVE: This study explored the factors likely to influence introduction of a novel oxytocin formulation for the prevention of postpartum hemorrhage in Ethiopia. METHODS: Qualitative research methods were used to assess barriers and enablers associated with pre-determined domains: regulatory approval, pricing, supply and demand side advocacy, policy inclusion, end-user training and drug supply. Data were collected through focus group discussions and in-depth interviews with community members, healthcare providers and key informants. Verbatim transcripts were translated to English and analyzed using a thematic content framework. RESULTS: Approval from stringent regulatory bodies was an enabler for gaining national regulatory approval. Purchasers (government and patients) expressed price sensitivity but would be willing to pay a price comparable to or higher than current alternatives if improved quality is delivered. Endorsement from the World Health Organization was described as critical for national policy inclusion. Supply side advocacy should be directed towards the Ministry of Health, which is receptive to advice from reputable agencies with whom they have an existing relationship. Demand side advocacy should be delivered through existing health system channels such as Ministry of Health authorities (for healthcare workers) and community health workers (for community members). The requirement to purchase the product directly from a single manufacturer was highlighted as a potential barrier for entry into the local supply chain. CONCLUSION: This study highlighted several barriers and enablers associated with the introduction of a new drug product into the health system of Ethiopia. An advanced understanding of these influences can inform the design of locally-appropriate implementation strategies.

Assessing the operational feasibility and acceptability of an inhalable formulation of oxytocin for improving community-based prevention of postpartum haemorrhage in Myanmar: a qualitative inquiry.

OBJECTIVE: This study assessed the potential operational feasibility and acceptability of a heat-stable, inhaled oxytocin (IOT) product for community-based prevention of postpartum haemorrhage in Myanmar. METHODS: A qualitative inquiry was conducted between June 2015 and February 2016 through focus group discussions and in-depth interviews. Research was conducted in South Dagon township (urban setting) and in Ngape and Thanlyin townships (rural settings) in Myanmar. Eleven focus group discussions and 16 in-depth interviews were conducted with mothers, healthcare providers and other key informants. All audio recordings were transcribed verbatim in Myanmar language and were translated into English. Thematic content analysis was done using NVivo software. RESULTS: Future introduction of an IOT product for community-based services was found to be acceptable among mothers and healthcare providers and would be feasible for use by lower cadres of healthcare providers, even in remote settings. Responses from healthcare providers and community members highlighted that midwives and volunteer auxiliary midwives would be key advocates for promoting community acceptance of the product. Healthcare providers perceived the ease of use and lack of dependence on cold storage as the main enablers for IOT compared with the current gold standard oxytocin injection. A single-use disposable device with clear pictorial instructions and a price that would be affordable by the poorest communities was suggested. Appropriate training was also said to be essential for the future induction of the product into community settings. CONCLUSION: In Myanmar, where home births are common, access to cold storage and skilled personnel who are able to deliver injectable oxytocin is limited. Among community members and healthcare providers, IOT was perceived to be an acceptable and feasible intervention for use by lower cadres of healthcare workers, and thus may be an alternative solution for the prevention of postpartum haemorrhage in community-based settings in the future.