Patients' perspective on their drug therapy after bariatric surgery: A quantitative, cross-sectional interview study

Drug therapy in patients who have undergone bariatric surgery is challenging. We aimed to investigate the patients' perspective on their drug therapy. This should allow deriving tailored measures to better support patients and their healthcare professionals with drug therapy after bariatric surgery. We conducted a quantitative telephone-based interview study with patients who have undergone bariatric surgery. The interview consisted of assessments in three parts: (i) current drug therapy: prescription, administration and adherence, (ii) changes after bariatric surgery and (iii) adverse events. (i) The 105 enrolled patients were taking a median of 10 (range: 3-30) drugs. In 1017 of 1080 drugs (94%), expectations in drug effectiveness were (rather) met. Of the 105 patients, 27% reported difficulties in drug administration, 44% forgot to take their drugs at least one time and 20% reported deviations from the prescription. (ii) Sixteen percent of the patients observed changes in drug effectiveness or tolerability-additionally to therapy adjustment by physicians. (iii) Seventy-four percent recognised at least one adverse event right before and/or after bariatric surgery, most frequently in gastrointestinal disorders. Patients who have undergone bariatric surgery have to deal with many difficulties in drug handling and adverse events. Our study emphasises the need for better and more individual support for patients with their drug therapy after bariatric surgery and, therefore, suggests a multidisciplinary approach that includes pharmacists. The stronger involvement of the patients' perspective seems to be a valuable source in research and practice.

A comprehensive study of prescribing, administering and drug handling medication errors in ten wards of a university hospital after implementation of electronic prescribing, clinical pharmacists or medication reconciliation

Background and aim: Medication errors lead to preventable risks. Preventing strategies such as e-prescribing, clinical pharmacists and medication reconciliation have been implemented in recent years. However, information on long-term medication error rates in routine procedures is missing. Investigations: We aimed to identify predefined medication errors in ten wards of a university hospital where e-prescribing, clinical pharmacists and medication reconciliation have been partially implemented. Patient files were reviewed and routine processes were monitored for drug prescription errors (missing, unclear, outdated information), administration errors (wrong dispensed drugs) and drug handling errors (no light-, moisture-protection, wrong splitting, no separation of drugs, which ought to be taken by an empty stomach). Results: We analyzed 959 prescriptions with 933 solid peroral drugs for 182 patients (98 female, median age 66.5 years [Q25-Q75: 56-78 years]; the median number of drugs was 5 [Q25-Q75: 3-7]). The most frequent prescription error was a not specified drug form (91.1%). The most common administration error was a not adequately provided release dose formulation (72.7%). The lack of light protection for observed photosensitive drugs was the most frequent drug handling error (100%). We found a significantly higher amount of complete drug prescriptions with one of the implemented measurements e-prescribing, medication reconciliation and clinical pharmacists (Fisher's exact test two tailed, each p<0.001; CI 95%). Drug administration errors and drug handling errors were not significantly improved. Among the most frequently involved drug were drugs for acid-related disorders, immunosuppressant, and antineoplastic drugs. Conclusions: In the nearly 1,000 prescriptions and drugs analyzed, medication errors were still common. Various preventive strategies had been implemented in recent years, positively influencing the predefined errors rates.

Protocol for a randomized, placebo-controlled, double-blind phase IIa study of the safety, tolerability, and symptomatic efficacy of the ROCK-inhibitor Fasudil in patients with Parkinson's disease (ROCK-PD)

Background

The Rho-kinase (ROCK) inhibitor Fasudil has shown symptomatic and disease-modifying effects in Parkinson's disease (PD) models in vitro and in vivo. In Japan, Fasudil has been approved for the treatment of subarachnoid haemorrhage since 1995 and shows a favourable safety profile.

Objectives/design

To investigate the safety, tolerability, and symptomatic efficacy of ROCK-inhibitor Fasudil in comparison to placebo in a randomized, national, multicenter, double-blind phase IIa study in patients with PD.

Methods/analysis

We plan to include 75 patients with at least 'probable' PD (MDS criteria), Hoehn and Yahr stages 1-3, and age 30-80 years in 13 German study sites. Patients must be non-fluctuating and their response to PD medication must have been stable for 6 weeks. Patients will be randomly allocated to treatment with the oral investigational medicinal product (IMP) containing either Fasudil in two dosages, or placebo, for a total of 22 days. As primary analysis, non-inferiority of low/high dose of Fasudil on the combined endpoint consisting of occurrence of intolerance and/or treatment-related serious adverse events (SAEs) over 22 days will be assessed in a sequential order, starting with the lower dose. Secondary endpoints will include tolerability alone over 22 days and occurrence of treatment-related SAEs (SARs) over 22 and 50 days and will be compared on group level. Additional secondary endpoints include efficacy on motor and non-motor symptoms, measured on established scales, and will be assessed at several timepoints. Biomaterial will be collected to determine pharmacokinetics of Fasudil and its active metabolite, and to evaluate biomarkers of neurodegeneration.

Ethics/registration/discussion

After positive evaluation by the competent authority and the ethics committee, patient recruitment started in the 3rd quarter of 2023. ROCK-PD is registered with Eudra-CT (2021-003879-34) and clinicaltrials.gov (NCT05931575). Results of this trial can pave way for conducting extended-duration studies assessing both symptomatic efficacy and disease-modifying properties of Fasudil.

A prospective intervention study to identify drug-related emergency department visits comparing a standard care group and a pharmaceutical care group

BACKGROUND AND IMPORTANCE

Adverse drug reactions impose a major burden. Those adverse drug reactions might lead to hospitalization but are often not correctly identified in the emergency department (ED). Clinical pharmacists, although not routinely implemented, can help identify adverse drug reactions.

OBJECTIVE

The primary objective was to examine the drug association of ED visits in a pharmaceutical group with a clinical pharmacist integrated in the ED team compared with a standard group without additional support.

DESIGN/SETTING/PARTICIPANTS

This prospective intervention study was performed in the ED of a tertiary care university hospital in Leipzig, Germany. Patients who were ≥50 years old were included. From 1 March 2020 to May 31, 2020 patients were enrolled in the standard group. From 1 March 2021 to 31 May 2021, the pharmaceutical group was enrolled. The clinical pharmacist supported the ED team with patient´s detailed medication history and medication analysis. In both groups, patients were evaluated whether their ED visit was drug-related.

OUTCOME MEASURES AND ANALYSIS

The number of identified drug-related ED presentations were compared between the two groups. Interventions performed on adverse drug reaction management, causative drugs and patient characteristics were evaluated.

MAIN RESULTS

A total of 798 patients were enrolled in the standard group and 827 patients in the pharmaceutical group. Patients whose ED visit was drug-related had a median age of 77 years [(Q25-Q75) 63.5-83.5] and took 7 [(Q25-Q75) 5-8] drugs in standard group. In the pharmaceutical group median age was 78 years [(Q25-Q75) 66-83] and number of drugs taken was 9 [(Q25-Q75) 5.25-11]. 31 (3.9%) drug-related ED visits were identified in the standard group compared to 104 (12.6%) in the pharmaceutical group (OR 3.56; 95% CI 2.35-5.38). An intervention on the patient's pharmacotherapy was performed in 16 drug-related ED visits in standard group compared to 77 in the pharmaceutical group.

CONCLUSION

In this study the implementation of a clinical pharmacist was associated with improved identification of drug-related ED visits. Discontinuations of causal medications and dose reductions were significantly higher in the pharmaceutical group compared to the standard care group.

[Adverse drug reactions as cause of nonspecific symptoms in patients in the emergency department]

BACKGROUND

In a large proportion of patients admitted to the emergency department (ED), the initial main symptom is nonspecific. One possible reason for this, especially in older patients, may be adverse drug reactions (ADR) due to their frequent polypharmacy.

AIM

To illustrate the incidence of ADRs, the affected patient population including risk factors, and drug classes with ADRs leading to nonspecific symptoms. To provide practice recommendations for the management of ADRs in the ED.

MATERIAL AND METHODS

Presentation of the pharmacological principles on ADRs, statistics of pharmacovigilance centers as well as original literature including experiences from clinical practice and own projects.

RESULTS

In 10% of patients with nonspecific symptoms an ADR is responsible for presentation in the ED. In 60% of cases these ADRs are not correctly identified in the ED setting. A small number of drug classes are responsible for most of these referrals. Databases, risk stratification, clinical pharmacists, or clinical decision support systems are available to improve ADR identification and management. As these options are partly associated with considerable costs or the validation for German EDs is missing, a widespread application does not take place.

CONCLUSION

Correct identification of ADRs in patients with nonspecific symptoms in the ED is necessary to initiate adequate treatment. These ADRs are often overlooked because processes and tools for identification and management are not applied in the ED, leading to a lack of awareness. For high-risk patients in the ED, the focus should be on drug history, ideally considering patient-specific risk factors and specific drug classes.

Steady-state versus chemotherapy-based hematopoietic cell mobilization after anti-CD38-based induction therapy in newly diagnosed multiple myeloma

BACKGROUND

The incorporation of anti-CD38 monoclonal antibodies (mAb) in induction regimens of newly diagnosed transplant-eligible multiple myeloma (MM) patients has been established as a new standard. However, the optimal strategy of stem cell mobilization in this context is not yet clear.

STUDY DESIGN AND METHODS

From May 2020 till September 2022, we retrospectively reviewed patients receiving anti-CD38 mAb-based induction therapy followed by stem cell mobilization either in a steady-state protocol (SSM) using 10 μg/kg granulocyte colony-stimulating factor (G-CSF) for 5 days or in a chemotherapy-based protocol (CM) using 1-4 g/m2 cyclophosphamide and G-CSF.

RESULTS

Overall, 85 patients (median age 61 years) were included in the analysis. In total, 90 mobilization attempts were performed, 42 with SSM and 48 with CM. There was no significant difference in the median concentration of CD34+ cells in peripheral blood (PB) prior to apheresis between SSM and CM (61/μL vs. 55.4/μL; p = .60). Cumulative CD34+ yields did not differ between the groups with median of 6.68 and 6.75 × 106 /kg body weight, respectively (p = .35). The target yield (≥4 × 106 CD34+ cells/kg body weight) was reached in 88% (CM) and 86% (SSM), with a high proportion even after a single apheresis session (76% vs. 75%). Plerixafor was found to be more frequently used in SSM (52%) than in CM (23%; p < .01). A total of 83 patients underwent autologous transplantation and all were engrafted.

CONCLUSIONS

Stem cell collection in patients undergoing anti-CD38-based induction therapy is feasible with either CM or SSM, although SSM more frequently requires plerixafor.

[Scoring tool to identify patients at increased risk for drug-related problems: results of a point prevalence study at hospital admission]

INTRODUCTION

Drug therapy is a high-risk process and requires special attention, especially at sectoral borders. Pharmaceutical services such as medication review are appropriate measures to identify drug-related problems and thus improve the safety of drug therapy. Risk-scoring tools have been described in the literature as helpful for prioritizing medication reviews for patients at high risk for drug-related problems.

METHODS

In a multi-centre point prevalence study, we identified patients at increased risk for medication-related problems at hospital admission using the medication risk tool. In addition, the current level of implementation of pharmacy services was surveyed.

RESULTS

A total of 11 (58%; 11/19) hospital pharmacies in Saxony participated in the point prevalence survey. The scoring tool identified 32% (279/875) of patients at increased risk for medication-related problems (Meris score >12 group) at admission. Thereby, the number of drugs in the Meris score >12 group was 10.6 (average; standard deviation 3.5; n=279), while in the Meris score ≤12 group it was only five drugs per patient (average 4.6; standard deviation 2.8; n=596). The age of patients in the Meris score >12 group averaged 75.9 ± 11 years, while the age of patients in the Meris score ≤12 group averaged 60.6 ± 17.9 years.

DISCUSSION

Prioritization with the help of a risk-scoring tool is essential as pharmacy services in Saxon hospitals still need to be regularly established and in order to identify patients with an increased risk for drug-related problems at an early stage.

SARS-CoV-2 Vaccine Breakthrough Infections of Omicron and Delta Variants in Healthcare Workers

Understanding SARS-CoV-2 breakthrough infections in vaccinated healthcare workers is of key importance in mitigating the effects of the COVID-19 pandemic in healthcare facilities. An observational prospective cohort study was conducted in vaccinated employees with acute SARS-CoV-2 infection between October 2021 and February 2022. Serological and molecular testing was performed to determine SARS-CoV-2 viral load, lineage, antibody levels, and neutralizing antibody titers. A total of 571 (9.7%) employees experienced SARS-CoV-2 breakthrough infections during the enrolment period, of which 81 were included. The majority (n = 79, 97.5%) were symptomatic and most (n = 75, 92.6%) showed Ct values < 30 in RT-PCR assays. Twenty-four (30%) remained PCR-positive for > 15 days. Neutralizing antibody titers were strongest for the wildtype, intermediate for Delta, and lowest for Omicron variants. Omicron infections occurred at higher anti-RBD-IgG serum levels (p = 0.00001) and showed a trend for higher viral loads (p = 0.14, median Ct difference 4.3, 95% CI [-2.5-10.5]). For both variants, viral loads were significantly higher in participants with lower anti-RBD-IgG serum levels (p = 0.02). In conclusion, while the clinical course of infection with both the Omicron and Delta variants was predominantly mild to moderate in our study population, waning immune response over time and prolonged viral shedding were observed.

Analysis of stem cell collections in adult patients with Ewing sarcoma

BACKGROUND

Ewing sarcoma is one of the most frequent soft-tissue tumors in pediatric patients. The current treatment protocols recommend stem cell apheresis (SCA) after completion of the second course of induction therapy with vincristine, ifosfamide, doxorubicine, and etoposide (VIDE). The feasibility of SCA and graft compositions in adult patients with Ewing sarcoma have not been previously analyzed.

METHODS AND MATERIALS

The authors analyzed 29 stem cell collections of 19 adult patients (9 male, 10 female) at a median age of 27 (range 19-53) years mobilized after VIDE (n = 17), cyclophosphamide/topotecan (n = 1) or vincristine, dactinomycin and ifosfamide (n = 1) chemotherapy. All patients were mobilized with filgrastim 5 μg/kg twice daily from day +7 of chemotherapy. The collections were performed if CD34+ cell count in peripheral blood was >10/μL. The target yields were ≥4×10⁶ CD34+ cells/kg body weight.

RESULTS

Median CD34+ cells/μL in peripheral blood before SCA were 45.8 (range 6.7-614.4)/μL. The median cumulative yields were 10.6 (range 1.5-38.8) CD34+ cells/kg body weight and ≥2×10⁶ in all but two patients (89%). CD34, CD3, and CD56 yields in collections after the third VIDE and after later courses did not differ. Four patients underwent high-dose therapy with autologous transplantation, and all were engrafted.

DISCUSSION

Stem cell mobilization is feasible in most Ewing sarcoma patients. Additionally, the present study's data suggest that it is safe to postpone stem cell collection to a later VIDE chemotherapy cycle if medically indicated.

Assessment of Patients' Views on Drug Benefits and Risks: An Interview Study with Cardiovascular Patients

Better and balanced information strategies supporting cardiovascular patients' adherence are required. Cardiovascular drugs have outstanding morbidity and mortality benefits. This can be counteracted by patients' perceptions of risks. Drug information should help the patient but not fuel unwarranted fears. We performed a cross-sectional survey of patients admitted to a cardiology ward. We evaluated (i) the patients' general benefit-risk estimation of their pharmacotherapy; (ii) views on benefits; (iii) views on risks; and (iv) information sources. Additionally, we assessed aspects of anxiety and depression with the Patient Health Questionnaire-4 (PHQ-4). (i) 67 patients (66%) rated expected drug benefits higher than potential risks. (ii) 72% of benefits motivated the patients to take their medication as prescribed. Patients more frequently mentioned surrogate markers as benefits than clinical benefits (p < 0.001). (iii) 56% of risks mentioned were perceived as bothersome and 35% as concerning. Risks were more often perceived as bothersome and concerning by patients with higher PHQ-4 scores (p=0.016). (iv) Physicians were the most frequent information source of benefits (92% of patients) and risks (45%), and pharmacy staff for 27% and 14%, respectively. Laymen or media served as sources of information on benefits in 39%, for risks in 40%, and package leaflets in 26% and 36%. 42% of the patients would like to receive more information on benefits versus 27% on risks. Our results suggest that knowledge of benefits motivates patients to take their drugs as prescribed. There is already good information on surrogate markers for process control with active patient involvement. However, a lack of knowledge still exists in relation to clinical benefits. Regarding risks, it has been shown that patients with higher PHQ-4 scores are more likely to be bothered or concerned. Both emphases on clinical benefits and individualization depending on PHQ-4 scores may be valuable resources for patient counseling to support adherence.

Stem-cell mobilization of healthy sibling donors with pegfilgrastim-A prospective open-label phase II trial (EudraCT no: 2005-004971-39)

BACKGROUND

Pegfilgrastim is a covalently bound conjugate of filgrastim and mono-methoxypolyethylene glycol with a longer half-life.

STUDY DESIGN AND METHODS

We report on phase II prospective monocentric trial examining the feasibility of stem cell mobilization with 12 mg single dose pegfilgrastim in related donors. The objectives were to determine the optimal collection day, defined as CD34+ concentration in peripheral blood (PB) >50 cells/μl, the number of donors collected with single leukapheresis, and the peak level of pegfilgrastim in donor-serum. Furthermore, the cell composition of grafts was assessed and compared to published data.

RESULTS

The results included about 28 matched related donors. The median pegfilgrastim serum level remained >200 ng/mL for 48 hours before declining, with the maximal measured concentration of 259.49 ng/ml 24 h after application. The median white blood cell count and CD34 count in PB peaked on day four with 52.6 (range 22.8-85.0) Gpt/l and 66.25 (range 22.9-136.6) cells/μl, respectively. A CD34+ count >50 cells/μl on day four was detected in 75% of donors. 79% of the donors underwent a single collection. Conventional filgrastim was administered additionally in two donors, due to insufficient CD 34+ concentration in PB. 89% of donors showed CD34+ yields ≥4 (median 6.5, range 4.6-14.5) × 10/kg body weight of the recipient. All grafts were administered without rejections.

DISCUSSION

The results of this trial showed that stem cell mobilization with pegfilgrastim is a feasible, and attractive option. This is the first trial presenting the kinetics of pegfilgrastim serum levels in healthy donors.

Case Report: Allogeneic Stem Cell Transplantation Following Induction With CPX-351 in Patients With Acute Myeloid Leukemia Is Feasible

Acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) and treatment-related acute myeloid leukemia (tAML) after chemotherapy or radiation therapy for other neoplasms are associated with poor outcomes. CPX-351, a dual-drug liposomal encapsulation of daunorubicin and cytarabine, has been shown to improve outcomes in AML-MRC and tAML compared with standard 7+3 regimens. Here we report the cases of four consecutive patients with AML-MRC or tAML who received CPX-351 as outpatient induction therapy immediately followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). Two patients received allo-HSCT in remission (one in complete remission and one in partial remission) and two patients received allo-HSCT in aplasia (one at 11 days and one at 52 days after the start of induction therapy with CPX-351). With a median follow-up of 188 days after allo-HSCT, all but one patient are alive and two are in remission. Further studies will help define and expand the role of CPX-351 in the treatment of AML-MRC and tAML, especially in patients expected to undergo allo-HSCT.

[Perioperative safety of intraperitoneal aerosol chemotherapy : Analysis of our first 111 pressurized intraperitoneal aerosol chemotherapy (PIPAC) procedures]

BACKGROUND

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new tool in the treatment of patients with peritoneal carcinomatosis. The aerosol containing chemotherapeutic drugs is administered laparoscopically into the abdominal cavity to achieve a local treatment effect. This can be carried out in combination with systemic chemotherapy.

MATERIAL AND METHODS

Within the framework of a register study, we prospectively documented and evaluated the data of our first 111 PIPAC procedures. The analysis focused on perioperative patient safety and safety at the workplace. Perioperative clinical patient data were analyzed and the platinum concentration in the operating room was checked by wipe samples.

RESULTS

A total of 62 patients were scheduled for PIPAC and 121 operations were carried out. In 9 procedures a secure access to the abdomen could not be found and 54 patients received 111 PIPAC treatments. One patient died as a result of intestinal perforation, six bowel lesions were treated immediately and healed without further complications. A further patient developed a postoperative renal failure. Otherwise, there was no major complications and no cases of toxicity.

CONCLUSION

The PIPAC procedure can be used as a supplement to systemic drug treatment for peritoneal carcinomatosis. An exact selection of suitable patients is important. The PIPAC is a low-risk procedure when performed under strict inclusion criteria and under standardized conditions, for the patients and also the surgical staff.

A stability study of amphotericin B, colistin and tobramycin in a hydrophilic suspension commonly used for selective decontamination of the digestive tract by HPLC and in vitro potency measurements

Objectives

A suspension for oral use which consists of three non-absorbable antibiotics (amphotericin B, colistin and tobramycin) is often used in clinical practice for the selective decontamination of the digestive tract (SDD) of patients in intensive care. Such a therapy is a preventive tool to minimise the risk of pneumonia and bacteraemia in intubated patients. The administration and the treatment results are controversially discussed. One limiting factor for a unique SDD treatment in the hospitals is a lack of adequate data regarding batch formula and stability for such a formulation. Since no detailed procedures, specifications or stability data are available for manufacturing this formulation there may be discrepancies regarding formulation and stability of suspensions prepared in different pharmacies. The aim of this research was to collect the physicochemical and microbiological stability data of a developed, stable standard formulation under defined storage conditions. The effectiveness of the SDD suspension should be preferably proven over a long period. This would help guarantee that all patients receive the same preparation, therefore, ensuring similar efficacy and improved safety.

Methods

An adequate formulation composed of the registered, marketed medicinal product Ampho-Moronal suspension (Dermapharm AG, Germany) and a buffered, preserved aqueous solution of colistin and tobramycin both as sulfates has been developed. A stability study has been performed on two batches of the formulation. During the storage, samples were taken and compatibility was verified by physicochemical and microbiological testing in stability-indicating terms of colour, odour, flavour, pH, chemical and microbiological purity as well as in vitro potency. The test methods were built and tailored to be suitable, reliable and precise for the test needs.

Results

The results show the physicochemical and microbiological stability of the described formulation for defined storage conditions.

Conclusions

A standardised formulation with a proven stability for at least 6 months under fridge (5°C±3°C) conditions for the SDD of patients in intensive care was established.

Transfer of the experimental methodology described in the FDA guidance for corticosteroid bioequivalence testing to pharmacodynamic effects caused by nicotinates

BACKGROUND

The measurement of the pharmacodynamic response allows the noninvasive quantification of cutaneous drug penetration.

AIMS

The objective of this study was to investigate whether the experimental methods described in the US Food and Drug Administration Guidance for Industry "Topical Dermatologic Corticosteroids: In vivo Bioequivalence" may be transferred to other response parameters such as skin redness and surface temperature.

METHODS

Drug penetration experiments with methyl nicotinate in two different lipophilic vehicles were performed according to the FDA guidance for corticosteroid bioequivalence testing measuring the cutaneous erythema and skin temperature response.

RESULTS

The guidance methodology was transferred to the response parameters redness and temperature. Bioequivalence testing was feasible with these response parameters.

CONCLUSIONS

An open one-compartment model could only be confirmed for skin redness data by a compartmental analysis of response vs. time profiles. The obtained temperature data can neither be described by an open one-compartment nor by a two-compartment model. A correlation between skin color and skin surface temperature could not be found.

Time of Erythema Onset after Application of Methyl Nicotinate Ointments as Response Parameter: Influence of Penetration Kinetics and Enhancing Agents

The time of erythema onset may be used as a response parameter for quantification of the cutaneous erythema response induced by methyl nicotinate. The vehicles light mineral oil (LMO; test) and medium chain triglycerides (MCT; standard) were compared with regard to the pharmacodynamic response. Moreover, the influence of penetration enhancers on the time of erythema onset was investigated under zero order penetration kinetics. The enhancers dimethyl sulfoxide, diethylene glycol monoethyl ether and three different glycerides in different concentrations were added to MCT as a standard vehicle. All preparations were applied to the forearms of volunteers under infinite dose conditions at different thermodynamic drug activity levels (0.2-3.2% of the saturation level) and different drug concentrations (0.051-0.816%), respectively. Different penetration kinetics do not influence data of erythema onset, as these data are comparable to those obtained under finite dose conditions (first order penetration kinetics). With regard to the penetration enhancers, a significantly enhanced penetration of methyl nicotinate could be observed only for diethylene glycol monoethyl ether and dimethyl sulfoxide. However, no significant difference between light mineral oil and MCT could be found with regard to penetration enhancement. The time of erythema onset is an easy and efficient parameter for quantification of the pharmacodynamic response caused by nicotinates.

Percutaneous Penetration of Methyl Nicotinate from Ointments Using the Laser Doppler Technique: Bioequivalence and Enhancer Effects

Laser Doppler flowmetry (LDF) may be used to quantify erythema response as a result of an increased cutaneous microcirculation induced by methyl nicotinate (MN). Bioequivalence of a test and a standard preparation (vehicles: light mineral oil and medium chain triglycerides, respectively) was confirmed according to the pilot study of the FDA Guidance for Industry "Topical dermatologic corticosteroids: In Vivo bioequivalence" applying the staggered application and synchronized removal method for one defined concentration. Furthermore, the influence of penetration enhancers (5% w/w Dimethylsulfoxide (DMSO) and 10% w/w diethylene glycol monoethyl ether) on MN penetration was investigated. It was shown that DMSO and diethylene glycol monoethyl ether altered cutaneous microcirculation and thus MN penetration in comparison to the standard formulation. However, true penetration enhancement could only be proved with diethylene glycol monoethyl ether resulting from an improved drug solubility in the skin which was confirmed by attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR). Increased MN penetration by DMSO was only caused by thermodynamic effects, i.e. a decreased drug solubility in the vehicle.