Nizhenkovska I.V. MD, Afanasenko O.V. PhD

Bogomolets National Medical University, Kijev, Ukraine

FEATURES OF EXPRESS-ANALYSIS STUDY OF PHARMACY PRODUCTION DRUG FORMS BY THE EXAMPLE OF CONCENTRATED SOLUTIONS

 

Nowadays, according to the credit-modular system of educational process organization, the “pharmaceutical chemistry” discipline is considered to be professionally-orientated for the training of general profile pharmacists. One of the sections of pharmaceutical chemistry is the analysis of pharmacy production drug forms, the first of which concentrated solutions are. Concentrated solutions belong to the type of undosed pharmacy preform which is used for the production of dosage forms with liquid dispersed medium by dilution or by mixing with other drugs. Concentrated solutions are usually called concentrates. Usage of concentrated solutions facilitates the work of a pharmacist, improves the quality of finished drugs.  Since concentrated solutions are widely used by pharmacist-technologists for the preparation of a wide range of inside pharmacy drug forms, it is needed that pharmacist-analyst must possess all of concentrated solutions quality control techniques.

         Nomenclature of concentrated solutions is defined by the assortment of ex tempore of the pharmacy company. In pharmacies concentrated solutions are prepared in quantities that can be used within expiration date. Terms of use of concentrated solutions depend on their resistance and ​​can be vary from 2 to 20 days.  Due to the fact that the concentrated solutions may be a breeding ground for microorganisms, they must be prepared under aseptic conditions using purified water. After preparation concentrated solutions are filtered and a full chemical analysis is carried (identification, transparency, quantitative definition). Norms of tolerance for solutions containing up to 20%  substance equal ± 2 %; if more than 20%, then ± 1 %. If quantitative content differs from the necessary then correction is performed either by dilution or strengthening solution. Concentrated solutions are again analyzed after this. Since concentrated solutions are used for the preparation of drug forms, they need to satisfy stricter requirements and the analysis is carried out according to pharmacopoeia methods.

During the laboratory classes students strengthen the theoretical knowledge and master the necessary practical skills and abilities for the quality control of pharmacy production drugs. Quality control includes the identification, establishment of purity (appearance, color, transparency, non-mechanical impurities) and the quantification of substance.

Plan of  laboratory work:

1.Written survey and testing

2. Teacher explanations related to the lesson

3. Independent lab work for students

4. Final testing, lab work report writing and defending

Students have to analyze the two drug forms in "Concentrated solutions" theme - Formulation №1 «Solutio Magnesii sulfati 20%" and Formulation №2 «Solutio Hexamethylentetramitum 20%".

In the Formulation №1 students need to identify magnesium cations. This is done using the appearance of white crystalline precipitate with sodium dihydrogen phosphate and ammonium hydroxide. The identification of sulphate-ions is also made using the formation of white precipitate of barium sulphate, which is insoluble in acids and alkalis. Quantitative determination of magnesium sulfate in a drug form is performed by chelatometry, and also by conducting of a comparative analysis by refractometry.

In the Formulation №2 the identification of hexamethylenetetramine (hexamine) is carried out by the use of acid hydrolysis products - formaldehyde and ammonia. Formaldehyde is identified by the formation of pink aurinic dye after the interaction of it with salicylic acid. Ammonia is determined by smell. Quantitative determination is performed by direct acidimetry method. Titration of an aliquot is made using concentrate hydrochloric acid and a mixed indicator (methyl orange and methyl blue).

At the end of the lesson, students calculate the quantitative content of the active substance in the drug form, norms of tolerance and then fill the laboratory journal and defend the results of their work. At the end of class, based on the test results and practical work teacher sets grades according to the following criteria:

"Excellent" grade corresponds to 7 points and is given to a student who answered to 90-100% of format A test, demonstrates the proper execution of practical work, uses the theoretical knowledge to solve practical problems and solves the problems of high complexity.

"Good" grade corresponds to 5.5 points and is given to a student who answered to 70-89% of format A tests, demonstrates the proper execution of practical work, uses the theoretical knowledge to solve practical problems and solves the problems of easy and moderate difficulty.

"Satisfactory" grade corresponds to 4 points and is given to a student who answered to 50-69% of format A tests, makes mistakes during practical work, cannot give a clear and logical answer to the question by himself and is able to solve the easiest problems.

"Unsatisfactory" grade corresponds to 1 point and is given to a student who answered less than 50% of format A tests, did not do the practical work, cannot give a clear and logical answer to the question and cannot solve the easiest problems.

 

Literature

1.     Методичні вказівки до лабораторно-практичних занять з фармацевтичної хімії для студентів ІV курсу фармацевтичного факультету. Укладачі: Ніженковька І.В., Глушаченко О.О. та ін.., НМУ, Київ 2012. – 110 стор.

2.      Методические рекомендации по анализу концентратов, полу­фабрикатов и внутриаптечной заготовки лекарственных средств, изго­товляемых в аптеках. Вып. 1 и 2. Сост. Л. В. Чернова, Д. Н. Синев.— Л. 1986.

3.      Арзамасцев А.П., Печенников В.М. и др. Анализ лекарственных смесей.— М.: Компания Спутник, 2000.— 275 с.

4.     Руководство к лабораторным занятиям по фармацевтической хи­мии / Под ред. А. П. Арзамасцева.— 2-е изд., доп. и перераб.— М.: Ме­дицина, 1995.— 320с.

5.     6. Руководство к лабораторным занятиям по фармацевтической хи­мии / Под ред. П. Л. Сенова.— 3-е изд., доп. и перераб.— М.: Медицина, 1978.—360с.