Stability of Oxytocin Preparations in Malawi and Rwanda: Stabilizing Effect of Chlorobutanol.

Oxytocin is used for the prevention and treatment of postpartum hemorrhage, the leading cause of maternal mortality in low- and middle-income countries. Because of the high instability of oxytocin, most products are labeled for storage at 2-8°C. Some other products are on the market which are labeled for non-refrigerated storage, but independent evaluations of their stability hardly exist. In the present study, seven brands (nine batches) of oxytocin were purchased from wholesalers and medical stores in Malawi and Rwanda and investigated by accelerated stability testing according to the ICH/WHO guidelines. Two oxytocin brands approved by a stringent regulatory authority (SRA) or by the WHO Prequalification of Medicines program and purchased in Europe were used as comparison. All investigated brands which were either produced in countries with SRAs, or were WHO-prequalified products, were labeled for storage at 2-8°C, and all of them passed stability testing with very good results. Even exposure to 25°C or 30°C for several months hardly affected their oxytocin content. However, two other investigated brands were labeled for non-refrigerated storage, and both of them had been produced in countries without SRAs. These two preparations showed not higher but lower stability than the brands labeled for storage at 2-8°C, and, for both of them, noncompliance with pharmacopoeial specifications was found after accelerated stability testing. At 40°C, and in forced degradation studies at 80°C, chlorobutanol showed a remarkable stabilizing effect on oxytocin, which may deserve further investigation. The results of the present study support the policy "Buy Quality Oxytocin, Keep It Cool."

Room temperature stable carbetocin for the prevention of postpartum haemorrhage during the third stage of labour in women delivering vaginally: study protocol for a randomized controlled trial.

BACKGROUND: Postpartum haemorrhage (PPH) is the leading cause of maternal mortality in low-income countries and contributes to nearly a quarter of maternal deaths globally. The current available interventions for prevention of postpartum haemorrhage, oxytocin and carbetocin, are limited by their need for refrigeration to maintain potency, as the ability to maintain a cold chain across the drug distribution and storage network is inconsistent, thus restricting their use in countries with the highest burden of maternal mortality. We describe a randomized, double-blind non-inferiority trial comparing a newly developed room temperature stable formulation of carbetocin to the standard intervention (oxytocin) for the prevention of PPH after vaginal birth. METHODS/DESIGN: Approximately 30,000 women delivering vaginally will be recruited across 22 centres in 10 countries. The primary objectives are to evaluate the non-inferiority of room temperature stable carbetocin (100 µg intramuscular) versus oxytocin (10 IU intramuscular) in the prevention of PPH and severe PPH after vaginal birth. The primary endpoints are blood loss ≥500 mL or the use of additional uterotonics (composite endpoint required by drug regulatory authorities) and blood loss ≥1,000 mL (WHO requirement). Non-inferiority will be assessed using a two-sided 95 % confidence interval for the relative risk of the above endpoints for room temperature stable carbetocin versus oxytocin. The upper limit of the two-sided 95 % confidence interval for the relative risk for the composite endpoint of blood loss ≥500 mL or the use of additional uterotonics, and for the endpoint of blood loss ≥1,000 mL, will be compared to a non-inferiority margin of 1.16 and 1.23, respectively. If the upper limit is below the corresponding margin, non-inferiority will have been demonstrated. The safety analysis will include all women receiving treatment. Safety and tolerability will be assessed by a review of adverse events, by conducting inferential testing with significance levels for between-group comparisons. DISCUSSION: If the results of the study show that room temperature stable carbetocin is a safe and effective alternative to oxytocin, this could have a substantial impact on the prevention of postpartum haemorrhage and maternal survival worldwide. TRIAL REGISTRATION: ACTRN12614000870651 (14 August 2014).

[Preparation of Cervical Dilatation Before with Misoprostol and Laminaria - Advantages and Disadvantages.]

The surgical hysteroscopy became popular as a minimally invasive approach to interuterine changes. Dilatation is a real challenge during surgical hyseroscopy especially in first delivery patients, women in menopause and women with cervical stenosis. Apart from this, some long hysteroscopy operations such as myomectomy require adequate dilatation in order to facilitate the multiple insertions and drawing pulling of the resectoscope. Another technical problem is the need for a significant degree of cervical dilatation, as well as softening of the cervix, which will allow the extraction of the excised endometrial polyps or myomatose parts. Mysoprostol is analogous to prostaglandin El, which is commonly used in obstetrics to induce an abortion and birth, as well as after birth to control the excessive vaginal bleeding. Its use in gynecology is limited. In our study it is of vital importance. The vaginal administration of MysoproStol before surgical hysteroscopy facilitates dilatation. The eased hysteroscopy minimizes cervical complications. On the other hand, the natural dilatators Laminaria, made of Laminariajaponica orLaminaria Digitata sticks, are attractive natural substances which can cause dilatation with minimally observed systemic side effects. They have shown efficient results during the cervical preparation before surgical hysteroscopy. Despite of that, there are no comparative studies on the efficiency of the two methods for cervical preparation. The aim of this Study is to compare the efficacy of internally vaginal Mysoprostol against endocervical dilatators Laminaria before surmical hvSterosconv in certain cases.

Salivary oxytocin in adolescents with conduct problems and callous-unemotional traits.

Callous-unemotional (CU) traits correlate with the severity and prognosis of conduct disorder in youth. The neuropeptide oxytocin (OT) has been linked to prosocial behaviors, including empathy and collaboration with others. This study discusses a possible role for OT in the biology of delinquent behavior. We hypothesized that in delinquent youth OT secretion will correlate with the severity of conduct problems and specifically with the level of CU traits. The study group included 67 male adolescents (mean age 16.2 years) undergoing residential treatment, previously assessed by an open clinical interview and history for the psychiatric diagnosis. Staff based Inventory of Callous-Unemotional traits for psychopathy and Strength and Difficulties Questionnaire were administered, and patients' medical and social personal files were systematically coded for previous history of antisocial acts using the Brown-Goodwin Questionnaire. Salivary OT was assayed by ELISA. Salivary OT levels were inversely correlated with conduct problems severity on Strength and Difficulties Questionnaire (r = -0.27; p ≤ 0.01). Recorded history of antisocial acts did not correlate with current OT levels. Odds ratio (OR) for significant CU traits among subjects with conduct problems was increased in low-OT (OR = 14, p ≤ 0.05) but not in high-OT subjects (OR = 6, p ≥ 0.05). Children with conduct problems and low levels of salivary OT are at risk for significant CU traits. These results suggest a possible role for salivary OT as a biomarker for CU traits and conduct problems severity.

Oxytocin is unequally distributed in a bag of normal saline--true or false?

Oxytocin infusion used in labour can sometimes be left hung on the stand for many hours. There has been no study to determine if oxytocin is equally distributed throughout the infusion bag and if the distribution stays the same with time. We postulated that there may be settling of the molecules such that oxytocin concentrates at the bottom of the infusion bag. Eight infusion bags were prepared by mixing 10 IU of oxytocin in 1 litre of normal saline. The infusion bags were hung on infusion stands for 8 hours after which 10 samples of 100 mls of the solution from each bag were taken in different containers and the concentration of oxytocin calculated using oxytocin specific Enzyme Immunoassay (EIA) in the different samples. No statistically significant correlation between the oxytocin concentration and the sample number was observed (p-value = 0.738). There was no obvious relationship between oxytocin concentration and the sample number in each bag. There was no evidence to suggest that a linear oxytocin concentration gradient develops in a bag of normal saline over an 8-hour period. In fact the distribution appears to be random and unequal.

In situ conjugation of dithiophenol maleimide polymers and oxytocin for stable and reversible polymer-peptide conjugates.

The in situ one-pot synthesis of peptide-polymer bioconjugates is reported. Conjugation occurs efficiently without the need for purification of dithiophenol maleimide functionalized polymer as a disulfide bridging agent for the therapeutic oxytocin. Conjugation of polymers was demonstrated to be reversible and to significantly improve the solution stability of oxytocin.

Oxytocin: taking the heat.

Oxytocin-in-Uniject satisfied the standards of its temperature-time indicator (TTI) in severe home storage conditions, although that required resupply every 30 days-a logistically onerous programmatic standard. Possible advances include: (1) incorporating TTIs with packaged batches of less expensive and more widely used conventional vials of oxytocin; (2) using TTIs calibrated more closely to the actual temperature sensitivity of oxytocin; and (3) researching whether a lower dose of oxytocin would be equally efficacious in preventing postpartum hemorrhage.

Cumulative effects of heat exposure and storage conditions of Oxytocin-in-Uniject in rural Ghana: implications for scale up.

OBJECTIVE: Postpartum hemorrhage can be reduced substantially in home deliveries attended by community-based workers by using Oxytocin-in-Uniject (OIU) devices affixed with temperature-time indicators. We characterized the distribution of time to discard of these devices when stored under normal field conditions in Ghana. METHODS: Two drug storage simulation studies were conducted in rural Ghana in 2011 and 2012. Devices were transported under refrigeration from manufacture (Argentina) to storage at the study site. Twenty-three field workers each stored at home (unrefrigerated) 25 OIU devices and monitored them daily to record: (1) time to transition from usable to unusable, and (2) continuous digital ambient temperature to determine heat exposure over the simulation period. Time to discard was estimated and compared with mean kinetic temperature exposure of the devices during the shipment and storage phases and with characteristics of the storage locations using Weibull regression models. We used the time to discard distributions in a Monte Carlo simulation to estimate wastage rates in a hypothetical program setting. RESULTS: Time for shipment and transfer to long-term refrigerated storage and mean kinetic temperature during the shipment phase was 8.6 days/10.3°C and 13.4 days/12.1°C, for the first and second simulation studies, respectively. Median (range) time to discard when stored under field conditions (unrefrigerated) was 43 (6 to 59) days and 33 (14 to 50) days, respectively. Mean time to discard was 10.0 days shorter in the second simulation, during which mean kinetic temperature exposure was 3.9°C higher. Simulating a monthly distribution system and assuming typical usage, predicted wastage of product was less than 10%. CONCLUSION: The time to discard of devices was highly sensitive to small changes in temperature exposure. Under field conditions typical in rural Ghana, OIU packages will have a half-life of approximately 30 to 40 days based on the temperature monitor used during the study. Program managers will need to carefully consider variations in both ambient temperature and rate of use to allocate the appropriate supply level that will maximize coverage and minimize stock loss.

Photodegradation of oxytocin and thermal stability of photoproducts.

Photodegradation of oxytocin at λ = 253.7 nm and λ ≥ 290 nm results in the transformation of the intrachain disulfide bond into predominantly dithiohemiacetal and thioether. Especially the dithiohemiacetal is sensitive to further degradation by light and/or elevated temperature, implying that the combination of an initial photostress and a subsequent heat stress can yield products significantly different compared with those observed under heat stress only.

Stability-indicating HPLC method for the determination of the stability of oxytocin parenteral solutions prepared in polyolefin bags.

Oxytocin is very commonly used in clinical settings and is a nonapeptide hormone that stimulates the contraction of uterine smooth muscles. In this study the stability of extemporaneously compounded oxytocin solutions was investigated in polyolefin bags. The sterile preparations of oxytocin were compounded to the strength of 0.02 U/mL in accordance with United States Pharmacopeia (USP) <797> standards. In order to carry out the stability testing of these parenteral products, the solutions were stored under three different temperature conditions of -20°C (frozen), 2-6°C (refrigerated), and 22-25°C (room temperature). Three solutions from each temperature were withdrawn and were assessed for stability on days 0, 7, 15, 21, and 30 as per the USP guidelines. The assay of oxytocin was examined by an HPLC method at each time point. No precipitation, cloudiness or color change was observed during this study at all temperatures. The assay content by HPLC revealed that oxytocin retains greater than at least 90% of the initial concentrations for 21 days. There was no significant change in pH and absorbance values for 21 days under all the conditions of storage. Oxytocin parenteral solutions in the final concentration of 0.02 U/mL and diluted in normal saline are stable for at least 30 days under frozen and refrigerated conditions for 30 days. At the room temperature, the oxytocin solutions were stable for at least 21 days. The stability analysis results show that the shelf-life of 21 days observed in this study was far better than their recommended expiration dates.

A new strategy to stabilize oxytocin in aqueous solutions: I. The effects of divalent metal ions and citrate buffer.

In the current study, the effect of metal ions in combination with buffers (citrate, acetate, pH 4.5) on the stability of aqueous solutions of oxytocin was investigated. Both monovalent metal ions (Na(+) and K(+)) and divalent metal ions (Ca(2+), Mg(2+), and Zn(2+)) were tested all as chloride salts. The effect of combinations of buffers and metal ions on the stability of aqueous oxytocin solutions was determined by RP-HPLC and HP-SEC after 4 weeks of storage at either 4°C or 55°C. Addition of sodium or potassium ions to acetate- or citrate-buffered solutions did not increase stability, nor did the addition of divalent metal ions to acetate buffer. However, the stability of aqueous oxytocin in aqueous formulations was improved in the presence of 5 and 10 mM citrate buffer in combination with at least 2 mM CaCl(2), MgCl(2), or ZnCl(2) and depended on the divalent metal ion concentration. Isothermal titration calorimetric measurements were predictive for the stabilization effects observed during the stability study. Formulations in citrate buffer that had an improved stability displayed a strong interaction between oxytocin and Ca(2+), Mg(2+), or Zn(2+), while formulations in acetate buffer did not. In conclusion, our study shows that divalent metal ions in combination with citrate buffer strongly improved the stability of oxytocin in aqueous solutions.

Complete NMR analysis of oxytocin in phosphate buffer.

Complete NMR analysis of oxytocin (OXT) in phosphate buffer was elucidated by one-dimensional (1D)- and two-dimensional (2D)-NMR techniques, which involve the assignment of peptide amide NH protons and carbamoyl NH(2) protons. The (1)H-(15)N correlation of seven amide NH protons and three carbamoyl NH(2) protons were also shown by HSQC NMR of OXT without (15)N enrichment.

Cyclic peptides from Oldenlandia affinis DC. Molecular and biological properties.

A new isolation procedure for Kalata polypeptides from the tropical plant Oldenlandia affinis DC is described. Fractions were screened by thin-layer chromatography, and Van Urk positive fractions were tested for oxytocic activity in estrogenized rat uteri. By using this procedure, we were able to isolate and characterize three macrocyclic polypeptides with uterine activity. Their amino acid sequence and biological effects have been analyzed, and their NMR spectra were compared with those of the earlier ones. All three peptides showed hemolytic activity on human blood, and were tested for antibiotic effect against E. coli, Staphylococcus aureus, and Hemophilus influenzae.

Design and optimization of potent, selective antagonists of Oxytocin.

A novel series of Oxytocin antagonists are described. This series was identified through pharmacophoric overlap of in-house and literature antagonists. Subsequent optimization led to a series of potent, selective antagonists. Several analogues displayed oral bioavailability in vivo in the rat.

Safety and efficacy of blue cohosh (Caulophyllum thalictroides) during pregnancy and lactation.

BACKGROUND: There is a lack of basic knowledge on the part of both clinicians and patients as to the indications for use and safety of herbal medicines in pregnancy and lactation. This is one article in a series that systematically reviews the evidence for commonly used herbs during pregnancy and lactation. OBJECTIVES: To systematically review the literature for evidence on the use, safety and pharmacology of blue cohosh, focusing on issues pertaining to pregnancy and lactation. METHODS: We searched 7 electronic databases and compiled data according to the grade of evidence found. RESULTS: According to a survey of midwives in the United States, approximately 64% of midwives reported using blue cohosh as a labour-inducing aid. There are three case reports in the scientific literature that blue cohosh taken at the time of delivery may cause; 1) perinatal stroke, 2) acute myocardial infarction, profound congestive heart failure and shock and 3) severe multi-organ hypoxic injury. There is one case report that blue cohosh possesses abortifacient properties. There is in vitro evidence that blue cohosh may have teratogenic, embryotoxic and oxytoxic effects. In lactation, the safety of blue cohosh is unknown. CONCLUSIONS: Based on the available scientific information, blue cohosh should; 1) be used with extreme caution during pregnancy, 2) be used only under medical professional supervision and 3) not be available to the public as an over-the-counter product. There is an urgent need to conduct a retrospective or prospective cohort study of midwifes using blue cohosh in order to determine its safety. Key words: Blue cohosh, caulophyllum thalictroides, pregnancy, lactation, breastfeeding, systematic review.

Safety and efficacy of chastetree (Vitex agnus-castus) during pregnancy and lactation.

BACKGROUND: There is a lack of basic knowledge on the part of both clinicians and patients as to the indications for use and safety of herbs used during pregnancy and lactation. This is one article in a series that systematically reviews the evidence for herbs commonly used during pregnancy and lactation. OBJECTIVES: To systematically review the literature for evidence on the use, safety and pharmacology of chastetree, focusing on issues pertaining to pregnancy and lactation. METHODS: We searched 7 electronic databases and compiled data according to the grade of evidence found. RESULTS In pregnancy, there is poor evidence based on theoretical and expert opinion and in vitro studies that chastetree may have estrogenic and progesteronic activity, uterine stimulant activity, emmenagogue activity and prevent miscarriages. In lactation, theoretical and expert opinion conflict as to whether chastetree increases or decreases lactation. CONCLUSIONS: Given its relatively common use amongst women of childbearing age, it is likely that some women may consume chastetree while unknowingly pregnant. Complementary and alternative medicine, midwifery and medical practitioners should be aware of this fact when prescribing chastetree to women of childbearing age, particularly when the patient is planning a family. Key words: Chastetree, vitex agnus-castus, pregnancy, lactation, breastfeeding, systematic review.

Method to determine stability and recovery of carboprost and misoprostol in infusion preparations.

The two synthetic prostaglandin analogues, carboprost and misoprostol, are used extensively in obstetric and gynaecological practice. Our recent research of these compounds' use for intra-umbilical injection to treat adherent placenta necessitated their storage in solution for 3-4 days. This raised concerns over the stability and applied dosage in the in-house infusion preparations. It requires various pharmacological preparations before administration in clinical practice. We used LCMS to develop a simultaneous, valid, fast and simple method to assess the stability and recovery of their in-house preparations in different conditions. The linearity between 0-40 microg/ml was above 0.995. The reproducibility (CV) was within 5.2%. The limit of quantitation of the method for both compounds is about 2 microg/ml. The accuracy of both compounds from 0.4-40 microg/ml is 96.4-104.3% while the precision is 0.4-7.4%. The recoveries of carboprost in the infusion were from 100.3+/-4.0 to 102.4+/-1.6% and that of misoprostol in Cytotec tablet was from 44.9+/-3.5 to 50.0+/-5.0% in water and saline at 4 degrees C and room temperature. No interference was found from the matrix and between the tested compounds. The compounds were basically stable for 6 days in water and in saline, whether they were stored at 4 degrees C or at room temperature. However, only half of the dosage of misoprostol was recovered in the solution. Therefore, misoprostol dosage should be adjusted before clinical application.

Stability of oral liquid preparations of methylergometrine.

The stability of an oral ready to-use form of methylergometrine (0.05 mg/mL), which provides a convenient volume for administration (5 mL), was evaluated over a forty-seven-day period at different temperatures (5 degrees C and room temperature) without light in order to assign a shelf life. Methylergometrine was assayed by a stability-indicating HPLC method with diode array detection. The drug undergoes degradation under basic conditions and dry heat (50 degrees C). All the peaks of the degraded product were resolved from the standard drug with significantly different retention times. Statistical analysis proves that the method is reproducible and accurate for estimation of the intact drug. The pH of samples was monitored periodically for changes. Samples were also visually inspected for any colour change, precipitation or crystallization. At least, 96% of the initial methylergometrine concentration remained throughout the 47-day study period. Over the test period, no significant change was observed in the pH or colour of any of the samples. No degradation products were revealed. This study allowed an oral ready to use solution of methylergometrine (0.05 mg/ml) to be prepared, with a shelf life of more than one month (47 days) when stored at room temperature without light.

The influence of modification at position 2 on the side-chain conformation in oxytocin analogs.

The nonapeptide oxytocin (OT) is used in medicine to help begin and/or continue childbirth. Its analogs can be also used to control bleeding following fetus delivery. The main function of oxytocin is to stimulate contraction of uterus smooth muscle and the smooth muscle of mammary glands, thus regulating lactation. This paper describes theoretical simulations of the distribution of the torsional angles chi1 in the non-standard methylated phenylalanine residues of three oxytocin analogs: [(Phe)(2)o-Me]OT, [(Phe)(2)m-Me]OT, [(Phe)(2)p-Me]OT. The conformations of the oxytocin analogs were studied both in vacuum and in solution. We found some correlations between the biological activity of the considered peptides and the side-chain conformations of amino-acid residues 2 and 8.