Formulating a poorly water soluble drug into an oral solution suitable for paediatric patients; lorazepam as a model drug

Chemical Stability of Lorazepam Oral Solution Repackaged in Plastic Oral Syringes at Room and Refrigerated Temperature

Purpose: Generic lorazepam oral solution is supplied in a 30 mL multi-dose bottle requiring protection from light and refrigeration, with a beyond use date of 90 days once the bottle is opened. The repackaging of 1 mL doses of lorazepam oral solution into oral syringes allows for facilitated dispensing, yet no available data supports repackaging and storing lorazepam oral solution in syringes. The validation and application of a stability-indicating high-performance liquid chromatography with ultraviolet detection (HPLC-UV) method for the quantification of lorazepam allowed for the determination of the stability of lorazepam oral solution when stored in oral syringes. Methods: A stability-indicating HPLC-UV method was developed for the quantification of lorazepam in oral solution. The method was validated using guidance from USP < 1225 >. For the stability investigation, 2 mg/mL lorazepam oral solution was aliquoted into clear plastic oral syringes in 1 mLmilliliter doses from 2 multi-dose stock bottles and randomly allocated for storage in room temperature or refrigerated environment. Baseline lorazepam concentrations were measured on the day the study was initiated and designated as 100% initial concentration samples. Subsequent samples were analyzed in triplicate at time points of 24, 48, and 96 hours and 7, 10, 14, 21, 30, and 60 days. Results: The calibration curves on three non-consecutive days met the linearity criteria of R 2 > 0.99. Inter- day and intra-day precision and accuracy (percent relative standard deviation and percent error) were ≤2% over three days. During the stability investigation, percent initial concentration of lorazepam from room and refrigerated syringes remained above 90% for the duration of the study. Conclusion: The stability-indicating HPLC-UV method was successfully applied to the investigation of lorazepam oral solution stability when stored in syringes at room and refrigerated temperatures. The emergent need for use of lorazepam concentrate for inpatients and the restrictions of how the medication is supplied necessitated a need for the evaluation of repackaging into unit dose syringes for immediate availability from automated dispensing cabinets. Lorazepam oral solution stored in clear plastic syringes maintained greater than 90% initial concentration at both room and refrigerated temperatures for 60 days.

Percutaneous absorption and Skin accumulation of Lorazepam-Diphenhydramine- Haloperidol Carbopol gel in Porcine Ear Skin

This study presents the formulation and evaluation of an ABH Carbopol gel containing lorazepam (Ativan®), diphenhydramine hydrochloride (Benadryl®), and haloperidol (Haldol®) for treating chemotherapy-induced nausea and vomiting (CINV) in hospice patients. ABH PLO gel is widely used for this purpose due to its low cost and presumed efficacy. However, previous studies, including one conducted by the authors, have reported insufficient drug absorption from the ABH PLO gel. Here we hypothesized that the ABH Carbopol gel would provide superior percutaneous absorption of the drugs. ABH Carbopol gel was characterized for pH, viscosity, thermal properties, and infrared spectroscopy. The percutaneous absorption and skin retention of the gel was evaluated across porcine ear skin using Franz diffusion cells, and the drug concentrations were determined by high-performance liquid chromatography. The pH of the ABH Carbopol gel was found to be 6.80 ± 0.33, and the retention time of diphenhydramine, haloperidol, and lorazepam were 4.73, 7.11, and 18.69 minutes, respectively. The thermogram of the ABH Carbopol gel indicates the drugs were present in the dissolved state. Based on the flux data, the estimated steady-state concentration (Css) of diphenhydramine, haloperidol, and lorazepam were found to be 44.64 ng/ml, 2.58 ng/ml, and 20.1 ng/ml, respectively. These values were significantly higher than those obtained from the ABH PLO gel. In conclusion, the ABH Carbopol gel provides a promising alternative to the ABH PLO gel for treating CINV in hospice patients. Further studies are required to validate these findings in clinical settings.

Combined Use of Cyclodextrins and Amino Acids for the Development of Cefixime Oral Solutions for Pediatric Use

Cefixime (CEF) is a cephalosporin included in the WHO Model List of Essential Medicines for Children. Liquid formulations are considered the best choice for pediatric use, due to their great ease of administration and dose-adaptability. Owing to its very low aqueous solubility and poor stability, CEF is only available as a powder for oral suspensions, which can lead to reduced compliance by children, due to its unpleasant texture and taste, and possible non-homogeneous dosage. The aim of this work was to develop an oral pediatric CEF solution endowed with good palatability, exploiting the solubilizing and taste-masking properties of cyclodextrins (CDs), joined to the use of amino acids as an auxiliary third component. Solubility studies indicated sulfobutylether-β-cyclodextrin (SBEβCD) and Histidine (His) as the most effective CD and amino acid, respectively, even though no synergistic effect on drug solubility improvement by their combined use was found. Molecular Dynamic and ¹H-NMR studies provided insight into the interactions of binary CEF:His and ternary CEF:His:SBEβCD systems used to prepare CEF solutions, which resulted stable and maintained unchanged antimicrobial activity during the two-weeks-use in therapy. The ternary solution was superior in terms of more tolerable pH (5.6 vs. 4.7) and better palatability, being resulted completely odorless by a panel test.

Excipients in the Paediatric Population: A Review

This theoretical study seeks to critically review the use of excipients in the paediatric population. This study is based on the rules and recommendations of European and American drug regulatory agencies. On the one hand, this review describes the most frequent excipients used in paediatric medicine formulations, identifying the compounds that scientific literature has marked as potentially harmful regarding the side effects generated after exposure. On the other hand, this review also highlights the importance of carrying out safety -checks on the excipients, which, in most cases, are linked to toxicity studies. An excipient in the compilation of paediatric population databases is expected to target safety and toxicity, as in the STEP database. Finally, a promising pharmaceutical form for child population, ODT (Orally Disintegrating Tablets), will be studied.

Potential prediction of formulation performance in paediatric patients using biopharmaceutical tools and simulation of clinically relevant administration scenarios of nifedipine and lorazepam

AIMS

This study explores the impact of paediatric patient related factors and choice of formulation on the dissolution characteristics of nifedipine and lorazepam, 2 drug substances regularly applied in very young patients and in compounded formulations.

METHODS

Dissolution experiments were designed to reflect clinical practice in a paediatric hospital, with respect to dosage forms, feeding regimens and methods of administration. Solubility studies addressed the influence of age and prandial state. Drug solubility and dissolution experiments were conducted in biorelevant media and adapted age-specific (neonate and infant) media. Dissolution studies were performed with the mini-paddle apparatus and the flow-through cell apparatus.

RESULTS

Dissolution of nifedipine formulations was not affected by age-related changes of the fasted state simulated gastrointestinal fluids, and by disintegration of the formulation before administration. However, a significant difference in nifedipine's dissolution rate from commercial tablets and compounded capsules was observed. The dissolution of lorazepam tablets was affected by fasted- vs fed-state media, but it was deemed less likely to be clinically relevant. The significant effect of fed-state media on nifedipine's solubility was considered to have possible clinical relevance since very young patients are almost continuously in a fed state.

CONCLUSION

The in vitro results obtained from these studies reveal the potential of biorelevant solubility and dissolution studies reflecting clinical practice to predict drug performance in paediatric patients.

A High-Demanding Strategy to Ensure the Highest Quality Standards of Oral Liquid Individualized Medicines for Pediatric Use

Individualized medicines for pediatrics are a useful alternative if there is no correct dosage marketed for this segment (easy to swallow, adequate volume and content, correct composition for pediatrics, good organoleptic properties, etc.). Its validation process must ensure quality testing: its content uniformity, physical (homogeneity after shaking), chemical, and microbiological stability. Some of these attributes are checked by the recommendations of European Pharmacopoeia (Ph. Eur.), International Conference of Harmonization (ICH), and National Formularies but others are not. The aim of this study is to develop a general high-demanding strategy to ensure the final quality of liquid dosage forms testing and developing standard operating processes (SOPs) for the elaboration of individualized oral liquid medicines for pediatric use. Furosemide was used as an example of the validation of an individualized liquid solution for pediatric use. Three SOPs were selected according to their composition and the recommendations of liquid dosage forms for pediatric use. Quality attributes according to National Formularies, Ph. Eur., and ICH were tested: pH, organoleptic properties, uniformity of mass of delivered dose from multidose containers, and chemical stability. In this study, a general high-demanding strategy was elaborated to validate oral liquid dosage forms, including validation of the analytical method used to test their quality. A second part focuses on the elaboration of liquid formulations for pediatrics with the highest standards of quality taking into account CQAs that were not contemplated by official compendial such as content uniformity and physical stability.

Oral lorazepam can be substituted for intravenous midazolam when weaning paediatric intensive care patients off sedation

AIM

Intravenous sedatives used in the paediatric intensive care unit (PICU) need to be tapered after prolonged use to prevent iatrogenic withdrawal syndrome (IWS). We evaluated the occurrence of IWS and the levels of sedation before and after conversion from intravenous midazolam to oral lorazepam.

METHODS

This was a retrospective, observational, single cohort study of children under the age of 18 admitted to the PICU of the Erasmus MC-Sophia Children's Hospital, Rotterdam, The Netherlands, between January 2013 and December 2014. The outcome parameters were the Sophia Observation withdrawal Symptoms (SOS) scale scores and COMFORT Behaviour scale scores before and after conversion.

RESULTS

Of the 79 patients who were weaned, 32 and 39 had before and after SOS scores and 77 had COMFORT-B scores. IWS was reported in 15 of 79 patients (19.0%) during the 48 hours before the start of lorazepam and 17 of 79 patients (21.5%) during the 48 hours after treatment started. Oversedation was seen in 16 of 79 patients (20.3%) during the 24 hours before substitution and in 30 of 79 patients (38.0%) during the 24 hours after substitution.

CONCLUSION

The weaning protocol was not able to prevent IWS in all patients, but converting from intravenous midazolam to oral lorazepam did not increase the incidence.