Design and stability study of a paediatric oral solution of methotrexate 2mg/ml

Olive Oil-Based Reverse Microemulsion for Stability and Topical Delivery of Methotrexate: In Vitro

Hydrolysis of pharmaceutically active molecules can be in control under a confined environment of water-in-oil microemulsion. Stability of model drug methotrexate (MTX) in a sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and olive oil microemulsion system has been evaluated. The physicochemical properties of AOT-MTX-water-olive oil reverse microemulsion (MTX-RM) were examined by UV-vis, Fourier transform infrared, and X-ray diffraction techniques, and the hydrodynamic size was determined by dynamic light scattering techniques and morphologies were characterized by a transmission electron microscope and atomic force microscope. In vitro permeation of MTX-RM through treated skin and its mechanism are evaluated by a UV-visible spectrophotometer, confocal laser scanning microscope, differential scanning calorimeter, and attenuated total reflecting infrared spectroscopy (ATR). The interaction of MTX with the AOT headgroup in confined environment RM enhanced the stability of MTX without affecting the molecular integrity at room temperature. Chemical stability of MTX in MTX-RM (W0 = 5) is significantly higher (∼97%) at room temperature for the study period of 1 year than in MTX-RM (W0 = 15) (∼72%). Interaction of MTX with the AOT headgroup is also visualized by a high-resolution transmission electron microscope and is in correlation with FT-IR data of MTX-RM. The skin fluxes of MTX are 15.1, 19.75, and 22.75 times higher at water content (W0) of 5, 10, and 15, respectively, in MTX-RM in comparison to aqueous solution of MTX. The enhanced amounts of the MTX were detected using CLSM in hair follicles, sweat glands, and epidermis layer of the skin. Merging of T2, T3, and T4 thermal peaks in one broad peak in treated skin endothermograph shows that carrier MTX-RM affects the lipid as well protein structure of the treated skin. ATR data of treated skin showed an increase in the intensity of the carbonyl peak at 1750 cm-1 (lipid), shifting of the amide II peaks, and separation of peaks in the range of 1060 to 1000 cm-1 (vibration mode of -CH2OH, C-O stretching, and C-OH bending peak of the carbohydrate) in comparison to control skin, which indicates that MTX-RM interacts with glycolipid and glycoprotein through carbohydrate hydroxy groups.

Hydrolytic stability of anticancer drugs and one metabolite in the aquatic environment

Due to the genotoxic, carcinogenic and teratogenic mechanism of action, anticancer drugs are highly hazardous compounds. Their occurrence, fate, and effects in the environment have not been systematically studied as compared to other medicaments. Therefore, reliable data, including their stability and persistency, is required in order to assess it. Taking into account, that hydrolysis is one of the most important factors regarding stability of chemicals in water, the aim of our study was to investigate the hydrolytic stability of five commonly used anticancer drugs (ifosfamide, cyclophosphamide, 5-fluorouracil, imatinib, and methotrexate) and one metabolite (7-hydroxymethotrexate), as the systematized and coherent data available is limited. The hydrolysis studies have been prepared according to the OECD 111 procedure to obtain standardized and comparable results. The preliminary tests at pH 4, 7, and 9 and 50 °C show that only cyclophosphamide and ifosfamide are unstable, whereas the estimated t_1/2 at 25 °C is >1 year for other investigated compounds. Moreover, much more detailed experiments were performed and indicate that at environmentally relevant temperatures, cyclophosphamide, and ifosfamide would be quite persistent in the terms of hydrolytic stability. Moreover, the preliminary investigation on the hydrolysis products was performed.

Stability of Extemporaneously Prepared Acetazolamide Oral Suspensions at Two Temperatures

OBJECTIVES

Some drugs need to be compounded by the pharmacist before being administered to the patient. A study was conducted to determine the stability of acetazolamide suspensions in 2 different vehicles (Oral Mix and Oral Mix Sugar Free [SF]) from bulk drug and tablets at 2 different temperatures and in 2 different containers (amber plastic bottles and clear plastic syringes).

METHODS

Acetazolamide suspensions (25 mg/mL) were prepared from bulk drug or tablets. Each suspension, using Oral Mix or Oral Mix SF, was split between 2 types of containers-amber plastic bottles and clear plastic syringes-and stored either at room temperature (23°C-27°C) or under refrigeration (3°C-7°C). Samples were drawn from the suspensions right after preparation and on days 7, 14, 30, 45, 60, 75, and 90. They were then analyzed by high-performance liquid chromatography (HPLC) using a reverse-phase column. A validated stability-indicating HPLC with ultraviolet detection method was developed. A visual inspection and a pH measurement were also completed at each time point. Stability was defined as retention of at least 90% of the initial concentration of acetazolamide suspension.

RESULTS

At least 91.2% of the initial acetazolamide concentration in suspensions remained throughout the 90-day study period for both vehicles, both containers, and both temperatures. Assays varied between 91.2% and 105.0% of the initial concentration for all 112 tested conditions but 2 (105.2% and 109.0%). Linear regression was calculated for each time profile and remained above 95.0% at the end of the study in all cases. Similarly, pH remained within 0.1 unit of the initial pH, which was 4.2 for Oral Mix and 4.3 for Oral Mix SF. Furthermore, no changes in organoleptic properties were observed because the preparations remained as white fluid suspensions without sedimentation.

CONCLUSIONS

Acetazolamide suspensions were stable for at least 90 days in all tested conditions because the average drug concentration was not less than 90% of the initial concentration. The beyond-use date could be extended from 60 to 90 days.

Orphan Formulations for Pediatric Use: Development and Stability Control of Two Sildenafil Citrate Solutions for the Treatment of Pulmonary Hypertension

Sildenafil citrate causes vasodilatation, relaxation of the smooth muscle, and reduction of pulmonary arterial pressure. The latter property makes sildenafil citrate efficient for the treatment of cardiovascular diseases, including pulmonary arterial hypertension. Pediatric patients with pulmonary arterial hypertension are more susceptible to errors in drug administration than adults because of a lack of suitable drug dosages. Thus, the purpose of this study was to develop stable (chemically and microbiologically) sildenafil citrate drop liquid formulation, suitable for pediatric patients (including diabetics), ensuring safety during preparation and storing and improving palatability by using milk as a carrier for administration. The significant factors that affect the sildenafil solubility were evaluated by applying a Plackett-Burman design using two levels with six variables. The experiment showed that the type of buffer and glycerin content influenced the sildenafil solubility. The developed formulations proved to be stable for 6 months at all three assayed conditions (40± 2°C, 75 ± 5% RH; 25± 2°C, 60 ± 5% RH; and 4 ± 2°C). The microbiological tests fit with the requirement of the pharmacopeia at day 0 and 90 and even more at day 180. Finally, the palatability assay showed that 0.82 mL of the formulation containing buffer phosphate, 20% glycerin, and 4 mg mL^-1 of sildenafil citrate diluted in 4.8 mL milk (which fits the medium pediatric dose) presented similar palatability to milk alone, and no precipitate or turbidity was observed. Graphical abstract.

Development and Stability Control of Pediatric Oral Tizanidine Hydrochloride Formulations for Hospital Use

Tizanidine hydrochloride is a centrally acting skeletal muscle relaxant used in the treatment of spasticity. This drug is sold only as tablets or capsules, which highlights the need to develop oral liquid formulations that allow administration to children and adults with impaired swallowing. This study aim was to develop and improve tizanidine hydrochloride liquid formulations from raw material and to evaluate their stability. A stability-indicating high performance liquid chromatography method was validated for two formulations developed. Fifteen formulations were developed containing syrup and fifteen containing sodium carboxymethyl cellulose as vehicles, to select the two most suitable for stability testing. The formulations were prepared in triplicate and placed in amber polyethylene terephthalate and glass bottles, which were stored under three different conditions: at room temperature (15-30°C), under refrigeration (2-8°C), and at 40°C. The physicochemical and microbiological stability of formulations were evaluated, applying high performance liquid chromatography and microbiological count. The studied formulations at 15-30°C, 2-8°C, and 40°C can be used for a period of 70 days, and all parameters are inside of recommended specifications, enough to allow its use in the context for which it was developed, the application in hospital. The formulations developed in this work have simple components to avoid adverse reactions in vulnerable populations. Results of this study could be applied as a reference for hospital use; once it demonstrated the reliability of storage time interval and proper conditions for use.

Validation of a stability-indicating HPLC-UV method for the quantification of acetazolamide in Oral-Mix and Oral-Mix SF

This manuscript details the modifications made to the HPLC assay method described in the USP monograph for Acetazolamide Compounded Oral Suspension.•

The method was modified to allow the quantification of acetazolamide in two new suspension vehicles: Oral Mix and Oral Mix SF;

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It was validated for linearity, accuracy, precision and specificity;

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It was demonstrated stability-indicating and suitable for use in a stability study using these vehicles.

First Development, Optimization, and Stability Control of a Pediatric Oral Atenolol Formulation

Liquid formulations can be used in children of different ages by varying the volume of the administered dose in order to ensure an exact dosage. The aim of this work was to develop and to optimize a safe liquid atenolol formulation and to carry out the corresponding chemical and microbiological stability studies. A Plackett-Burman design was used to determine the factors that could be critical in the development of the formulations, and a central composite design was used to determine the optimal working conditions. As a result of these analyses, three formulations were selected and their stability studied in three storage conditions, 4, 25, and 40°C. After 6 months of stability testing, the optimal systems showed no pH change or atenolol loss; however, only glycerin-based formulations showed no microbial development. These systems, employing excipients in a range that the EMA has recommended, showed chemical and microbiological stability for at least 6 months even at the worst storage conditions.

Stability of gabapentin in extemporaneously compounded oral suspensions

This study reports the stability of extemporaneously prepared gabapentin oral suspensions prepared at 100 mg/mL from bulk drug and capsules in either Oral Mix or Oral Mix SF suspending vehicles. Suspensions were packaged in amber plastic bottles and amber plastic syringes at 25°C / 60%RH for up to 90 days. Throughout the study period, the following tests were performed to evaluate the stability of the preparations: organoleptic inspection to detect homogeneity, color or odor changes; pH measurements; and gabapentin assay using a stability-indicating HPLC-UV method. As crystallization was observed at 5°C, storage at this temperature condition is not recommended. All preparations stored at 25°C / 60%RH remained stable for the whole study duration of 90 days.

Stability of Diazoxide in Extemporaneously Compounded Oral Suspensions

The objective of this study was to evaluate the stability of diazoxide in extemporaneously compounded oral suspensions. Oral suspensions of diazoxide 10 mg/mL were prepared from either bulk drug or capsules dispersed in either Oral Mix or Oral Mix Sugar Free. These suspensions were stored at 5°C and 25°C/60%RH in bottles and oral syringes for a total of 90 days. At predetermined time intervals, suspensions were inspected for homogeneity, color or odor change; the pH was measured and the concentration of diazoxide was evaluated by ultraviolet detection using a stability-indicating high pressure liquid chromatography method. All preparations were demonstrated to be chemically stable for at least 90 days.