Accelerated Stability Studies of Widely Used Pharmaceutical Substances Under Simulated Tropical Conditions
(1986; 119 pages) View the PDF document
Table of Contents
View the document1. Introduction
View the document2. Index of degradable substances
View the document3. Index of substances resistant to degradation
Close this folder4. Stability experiments on degradable substances
View the documentAcetylsalicylic acid
View the documentAminophylline
View the documentAmitriptyline hydrochloride
View the documentAmmonium chloride
View the documentAmphotericin B
View the documentAmpicillin sodium
View the documentAmpicillin trihydrate
View the documentAntimony sodium tartrate
View the documentAscorbic acid
View the documentBacitracin
View the documentBacitracin zinc
View the documentBenzathine benzylpenicillin
View the documentBenzylpenicillin potassium
View the documentBenzylpenicillin sodium
View the documentBephenium hydroxynaphthoate
View the documentCalcium gluconate
View the documentCalcium para-aminosalicylate
View the documentCarbenicillin sodium
View the documentCefalexin
View the documentChloral hydrate
View the documentChloramphenicol sodium succinate
View the documentChlorphenamine hydrogen maleate
View the documentChlorpromazine hydrochloride
View the documentChlortetracycline hydrochloride
View the documentCloxacillin sodium (monohydrate)
View the documentCoal tar (washed)
View the documentCodeine phosphate
View the documentColecalciferol
View the documentCresol
View the documentDapsone
View the documentDexamethasone sodium phosphate
View the documentDicloxacillin sodium (monohydrate)
View the documentDiethylcarbamazine dihydrogen citrate
View the documentDoxycycline hyclate
View the documentEmetine hydrochloride
View the documentEphedrine
View the documentEphedrine sulfate
View the documentEpinephrine
View the documentEpinephrine hydrogen tartrate
View the documentErgocalciferol
View the documentErgometrine hydrogen maleate
View the documentErgotamine maleate
View the documentErgotamine tartrate
View the documentEthosuximide
View the documentEthylmorphine hydrochloride
View the documentFerrous sulfate
View the documentFluphenazine decanoate
View the documentFluphenazine hydrochloride
View the documentFormaldehyde solution
View the documentGentamicin sulfate
View the documentGuanethidine sulfate
View the documentHexylresorcinol
View the documentHydralazine hydrochloride
View the documentHydrocortisone sodium succinate
View the documentHydroxocobalamin
View the documentHyoscyamine sulfate
View the documentImipramine hydrochloride
View the documentIpecacuanha powder
View the documentIsoprenaline hydrochloride
View the documentIsoprenaline sulfate
View the documentLidocaine hydrochloride
View the documentMelarsoprol
View the documentMercuric oxide yellow
View the documentMetrifonate
View the documentNaloxone hydrochloride
View the documentNeomycin sulfate
View the documentNystatin
View the documentOrciprenaline sulfate
View the documentOxytetracycline hydrochloride
View the documentParomomycin sulfate
View the documentPenicillamine
View the documentPethidine hydrochloride
View the documentPhenobarbital sodium
View the documentPhenoxymethylpenicillin
View the documentPhenoxymethylpenicillin calcium
View the documentPhenoxymethylpenicillin potassium
View the documentPhentolamine mesilate
View the documentPhenylbutazone
View the documentPilocarpine hydrochloride
View the documentPilocarpine nitrate
View the documentProcainamide hydrochloride
View the documentProcaine benzylpenicillin
View the documentProcaine hydrochloride
View the documentProcarbazine hydrochloride
View the documentPromazine hydrochloride
View the documentPromethazine hydrochloride
View the documentPyridoxine hydrochloride
View the documentQuinine bisulfate
View the documentQuinine dihydrochloride
View the documentRetinol (Vitamin A)
View the documentSalbutamol sulfate
View the documentSenna leaf
View the documentSilver nitrate
View the documentSodium calcium edetate
View the documentSodium lactate
View the documentSodium nitrite
View the documentSodium para-aminosalicylate
View the documentSodium stibogluconate
View the documentSulfacetamide sodium
View the documentSulfadiazine sodium
View the documentSulfadimidine sodium
View the documentSuxamethonium chloride
View the documentTetracaine hydrochloride
View the documentTetracycline hydrochloride
View the documentThiamine hydrochloride
View the documentThiamine mononitrate
View the documentThiopental sodium
View the documentTolbutamide
View the documentUndecylenic acid
View the documentWarfarin sodium


Accelerated Degradation Experiment


Procedure A1:

10 days exposure at 50 °C and 100% relative humidity.

Procedure A2:

20 days exposure at 50 °C and 100% relative humidity.

Appearance of the substance

The substance, originally in the form of a white or yellowish white, crystalline powder, changes after procedure A1 into a colourless liquid that recrystallizes at room temperature, and after procedure A2 recrystallization does not reoccur, not even at a temperature of 0 °C.

Gain of moisture

Before exposure to heat and humidity:

about 0.2%

After procedure A1:


After procedure A2:


Chromatographic test

Adsorbent: Silica gel F-254

Solution applied to the plate: Substance dissolved in water.

Solvent system:

chloroform .............. 6 volumes
acetone .................... 4 volumes

Development conditions; The solvent is allowed to migrate until the front reaches a line 15 cm from the starting line.

Detection: Prepare the following spraying solutions:

Solution I - 0.05 N silver nitrate in methanol.

Solution II - 30% aqueous solution of formaldehyde.

Solution III - 2 N potassium hydroxide in methanol.

Solution IV - A mixture of equal volumes of 40% nitric acid with an aqueous 3% hydrogen peroxide solution.

After drying the plate, spray it in the following manner: Spray with solution I, allow to rest at room temperature for 30 minutes; spray with solution II, allow to rest at room temperature for 30 minutes; spray with solution III, heat at 100 °C for 30 minutes; spray with solution IV, allow to rest in the dark overnight, then expose it to daylight for a few hours. Violet spots of the chlorine derivatives appear on a white background.

Results: The spots obtained from the solution of the sample subjected to procedure A1 is weaker by a factor of 2 with an important spot on the starting line when compared with the reference solution of metrifonate. The main spot is intensified after procedure A2.

Determination of ionisable chlorine by argentometry

Before exposure to heat and humidity: None.

After procedure A1:

2.8% calculated with reference to the dried substance.

After procedure A2:

5.1% calculated with reference to the dried substance.

Determination of free aldehydes

Absorbance of a reference solution of metrifonate containing 100 µg/ml: 0.075

Absorbance of a solution of the substance subjected to procedure A1 containing 100 µg/ml: 0.62

Absorbance of a solution of the substance subjected to procedure A2 containing 10 µg/ml: 0.22


Metrifonate is subject to decomposition under accelerated degradation conditions.

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