- تصييغ مستحضر ديازيبام محلول شرجي 0,05% (وزن / حجم)

Abstract

Abstract Several aqueous formulations were prepared using different solvents, ethanol (96%), propylene glycol, benzoic acid, sodium benzoate and purified water. The best formula was selected for physicochemical testing and further exposed to thermal stresses. This work has been carried out to formulation pharmaceutical product contains diazepam (0.05 %)( w/v) as rectal enema solution, it is used in emergency situations to control seizures, such as status epileptic and febrile convulsions in children. The stability study was conducted on the product for (6) months at different temperatures to determine the expiration date and the best storage conditions. The selected formula which contains (diazepam, ethanol (96%), propylene glycol, benzoic acid, sodium benzoate and purified Water) shows acceptable physical properties with estimated shelf life about (3) years .

Keywords:- diazepam, solution, seizure, epilepsy, enema solution.

Introduction Benzodiazepines (BZDs), including diazepam (DZP) and midazolam (MDZ), are drugs of choice for rapid treatment of seizure emergencies. Current approved use of these drugs involves administration via either intravenous or rectal routes .(1) Benzodiazepines represent the first choice treatment of acute repetitive seizures, and diazepam is one of the main drugs administered to epileptic patients in the prehospital setting.(2) Diazepam is a benzodiazepine with anticonvulsant, anxiolytic, sedative, muscle relaxant, and amnesic properties and a long duration of action. Its actions are mediated by enhancement of gamma-aminobutyric acid (GABA)activity. Diazepam potentiates the inhibitory activities of gamma-aminobutyric acid by binding to the GABA receptor, located in the limbic system and the hypothalamus. This increases the frequency of chloride channel opening, allowing the flow of chloride ions into the neuron and ultimately leading to membrane hyperpolarization and a decrease in neuronal excitability.(3) Current treatments for seizure emergencies, such as status epileptics, include intravenous or rectal administration of benzodiazepines. While intranasal delivery of these drugs is desirable, the small volume of the nasal cavity and low drug solubility pose significant difficulties. (4) Rectal diazepam can be given by a treating doctor when intravenous access cannot readily be obtained, as is often the case in infants. Rectal diazepam is often given instead of intravenous diazepam for prolonged convulsions when intravenous access cannot be obtained.(5) Diazepam is a white or almost white, crystalline powder, very slightly soluble in water, soluble in ethanol (96 per cent). (6) The formula contains diazepam (2.5 mg/5ml) as an active ingredient and it is a generic drug not manufactured in the Iraqi factories; therefore, the aim of study is a necessity to have an alternative dosage form that compatible with specifications of British pharmacopeia.

Experimental work Several formulations were prepared and the selected formula contains propylene glycol, ethanol (96 %),preservative and distilled water as inactive ingredients. In suitable beaker transfer the following materials, propylene glycol and ethanol (96 %) , then add the stated amount of diazepam , then mix well for (15) minutes, in another beaker transfer preservative and distilled water heat to (60) °C with water bath, mix well for (15) minutes ,cool to (45) °C, , mix all beakers, mix well for (15 )minutes, check the pH; it should be between (6.2 – 7.2),complete the volume with distilled water then mix well for (15 ) minutes, fill in 5ml plastic container. Table -1- list of ingredients Item no. ingredients Quantity 1 2 3 4 5 6 diazepam Benzoic acid Ethanol 96% Propylene glycol sodium benzoate Purified water 0.05gm 0.2 gm 15 gm 20gm 0.2gm Up to 100 ml

Assay method of diazepam rectal solution To a volume containing (10 mg) of diazepam add (20 mL) of mixed phosphate buffer (pH 7.0) and extract with four (20 mL) quantities of chloroform, passing each extract through the same (5 g) of anhydrous sodium sulfate. Combine the chloroform extracts, dilute to (100 mL) with chloroform and mix. Evaporate (10 mL) to dryness in a current of nitrogen, dissolve the residue in (25 mL) of (0.05M) methanolic sulfuric acid , mix and measure the absorbance of the resulting solution at the maximum at 368 nm, Appendix II B. Calculate the content of C16H13ClN2O taking (151) as the value of A(1%, 1 cm) at the maximum at( 368 nm).

Stability study Stability study was conducted on the product for (6)months at different temperatures(25,40,50,60)◦C to determine the expiration date and the best storage conditions.

Results and Discussion A clear colorless solution was obtained and the physicochemical properties of solution it is presented in table (3) .On the other hand , stability studies is presented in tables (4) and (5). In this study, different formulas of solution were prepared according to the a specification of British Pharmacopoeia 2013. A clear colorless solution of acceptable consistency was produced and the physicochemical also our formula showed excellent stability at different temperatures (25, 40, 50, and 60) ◦c. According to this study, the expiration date has been estimated to be not less than (3) years from the date of manufacturing at room temperature. Table-2- Quantitative composition of diazepam rectal solution Formulations (% w/v). Formula no. diazepam Ethanol 96% Propylene glycol Benzoic acid Sodium benzoate Purified water pH 1 0.05 10 20 0.2 0.2 Up to 100 ml 6.85 2 0.05 10 15 0.2 0.2 Up to 100 ml 6.85 3 0.05 10 10 0.2 0.2 Up to 100 ml 6.80 4 0.05 5 10 0.2 0.2 Up to 100 ml 6.80 5 0.05 5 5 0.2 0.2 Up to 100 ml 6.82 Table -3-Effected of temperatures on the content and physical properties of diazepam rectal solution. Storage time (month) Temp. ◦C %of diazepam pH (6.2 – 7.2) appearance Zero time 25 101 6.85 Clear colorless solution

1 25 101 6.85 Clear colorless solution 40 100.88 6.85 Clear colorless solution 50 100.54 6.84 Clear colorless solution 60 100.33 6.82 Clear colorless solution

2 25 100.86 6.84 Clear colorless solution 40 100.2 6.83 Clear colorless solution 50 99.86 6.80 Clear colorless solution 60 99.65 6.8 Clear colorless solution 3

25 100.74 6.81 Clear colorless solution 40 100.6 6.80 Clear colorless solution 50 99.77 6.80 Clear colorless solution 60 99.56 6.80 Clear colorless solution 4

25 100.43 6.80 Clear colorless solution 40 100.42 6.79 Clear colorless solution 50 99.43 6.79 Clear colorless solution 60 99.22 6.78 Clear colorless solution 5

25 100.25 6.78 Clear colorless solution 40 100 6.77 Clear colorless solution 50 99 6.72 Clear colorless solution 60 98.79 6.72 Clear colorless solution 6

25 99.8 6.74 Clear colorless solution 40 99.3 6.77 Clear colorless solution 50 98.57 6.70 Clear colorless solution 60 98.42 6.70 Clear colorless solution Table - 4 –Effect of storage time on diazepam rectal solution at different exaggeration temperatures 60◦c Conc.at % 50◦c Conc.at % 40◦c Conc.at % Concentration at 25◦c % Time /day 100.33 100.54 100.88 101 30 99.65 99.86 100.2 100.86 60 99.56 99.77 100.6 100.74 90 99.22 99.43 100.42 100.43 120 98.79 99 100 100.25 150 98.42 98.57 99.3 99.8 180 Regarding the expiry date of the prepared formula followed the rate of reaction that is expected for kinetic of diazepam rectal solution particularly in the first stage of reduction of concentration. T 90% =0.1C/K Where: C=concentration at zero time, K= rate of reaction , T= time Table -5 - The 90% at different temperatures. T 90%Year T 90% day Temp. 3.5 1277 R.T◦c 3.2 1168 40◦c 2.9 1058 50◦c 2.5 912 60◦c

Figure -1- curve for stability of diazepam rectal solution in different temperatures. References 1. Siegel RA, . Water-soluble benzodiazepine prodrug/enzyme combinations for intranasal rescue therapies, Epilepsy Behav. 2015 Aug;49:347-50. doi: 10.1016/j.yebeh.2015.05.004. Epub 2015 Jun 24. 2. Verrotti A1, Milioni M, Zaccara G, Safety and efficacy of diazepam autoinjector for the management of epilepsy, Department of Pediatrics, University of Perugia, Piazza Università 1, 06123, Perugia, Italy, 2015 Feb;15(2):127-33. doi: 10.1586/14737175.2015.1003043. 3- Onlinefrom, https://pubchem.ncbi.nlm.nih.gov/compound/3016#section, diazepam. 4. Kapoor M1, Winter T, Lis L, Georg GI, Siegel RA, Rapid delivery of diazepam from supersaturated solutions prepared using prodrug/enzyme mixtures: toward intranasal treatment of seizure emergencies, AAPS J. 2014 May;16(3):577-85. doi: 10.1208/s12248-014-9596-5. Epub 2014 Apr 4. 5. Charles O'Sullivan, Senior Pharmacist, The use of rectal diazepam for the treatment of prolonged convulsions in children, Aust Prescr 1998;21:35-6 | 1 April 1998 6. British Pharmacopoeia press, 2013, British Pharmacopoeia, U.K.

7- Kim Huynh,(2009),Accelerating aging, Handbook of stability testing in pharmaceutical development,springer ,USA .

الخلاصة نفذ هذا العمل لتحضير منتج صيدلاني يحتوي على الديازيبام (0.05٪) (وزن / حجم) كمحلول حقنة شرجية ، ويستخدم في حالات الطوارئ للسيطرة على االنوبات، مثل حالة الصرع والحمى التشنجات عند الأطفال. حضرت العديد من التركيبات المائية باستخدام المذيبات المختلفة، الإيثانول 96٪، البروبيلين غليغول، حمض البنزويك، بنزوات الصوديوم والمياه النقية. تم اختيار أفضل صيغة للاختبار الفيزيائي والكيميائي وعرضت كذلك للضغوط الحرارية. أجريت دراسة االثباتية على المنتج لمدة (6) أشهر في درجات حرارة مختلفة لتحديد تاريخ انتهاء الصلاحية وأفضل ظروف التخزين. إن الصيغة المختارة تحتوي على (الديازيبام، الإيثانول 96٪، البروبيلين جلايكول، حامض البنزويك، بنزوات الصوديوم والمياه النقية) تظهر الخصائص الفيزيائية المقبولة مع العمر الافتراضي المقدر حوالي (3) سنوات .