scholarly journals Hot-Stage Microscopy for Determination of API Particles in a Formulated Tablet

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Michal Šimek ◽  
Veronika Grünwaldová ◽  
Bohumil Kratochvíl
Keyword(s):  
Active Pharmaceutical Ingredient ◽  
Assessment Method ◽  
Hot Stage Microscopy ◽  
Tablet Disintegration ◽  
Before And After ◽  
In Vitro Assessment ◽  
Active Substances ◽  
Good Agreement

Although methods exist to readily determine the particle size distribution (PSD) of an active pharmaceutical ingredient (API) before its formulation into a final product, the primary challenge is to develop a method to determine the PSD of APIs in a finished tablet. To address the limitations of existing PSD methods, we used hot-stage microscopy to observe tablet disintegration during temperature change and, thus, reveal the API particles in a tablet. Both mechanical and liquid disintegration were evaluated after we had identified optimum milling time for mechanical disintegration and optimum volume of water for liquid disintegration. In each case, hot-stage micrographs, taken before and after the API melting point, were compared with image analysis software to obtain the PSDs. Then, the PSDs of the APIs from the disintegrated tablets were compared with the PSDs of raw APIs. Good agreement was obtained, thereby confirming the robustness of our methodology. The availability of such a method equips pharmaceutical scientists with an in vitro assessment method that will more reliably determine the PSD of active substances in finished tablets.

DETERMINATION OF BLOOD CORTICOIDS USING THE IN VITRO RESIN UPTAKE OF 3H-PREDNISOLONE

1968 ◽  
Vol 57 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Hironori Nakajima ◽  
Mitsunori Murala ◽  
Masumitsu Nakata ◽  
Takeshi Naruse ◽  
Seiji Kubo
Keyword(s):  
Thyroid Function Test ◽  
Normal Subjects ◽  
Adrenal Function ◽  
Function Test ◽  
Before And After ◽  
Adrenal Response ◽  
Suppression Test

ABSTRACT The in vitro resin uptake of 3H-prednisolone was used for the determination of blood cortisol after addition of radioactive prednisolone followed by Amberlite CG 400 Type 1 to the test serum, and incubation of the mixture. The radioactivity of the supernatant was compared before and after the addition of the resin. The principle of this method is similar to that of the 131I-triiodothyronine resin uptake for the thyroid function test. The tests for the specificity, reproducibility and sensitivity gave satisfactory results. The mean basal value ± SD of the 3H-prednisolone resin uptake was 35.3 ± 9.2% in normal subjects, and 27.1 ± 4.8% in pregnant women. This method was valid in various adrenal function tests, i. e. the adrenal circadian rhythm, corticotrophin (ACTH) test, dexamethasone suppression test and the adrenal response to lysine-8-vasopressin. It proved to be a sensitive indicator of the adrenal function. These results suggest that this method should be useful for a routine adrenal function test.

Self-assessment of Сompetencies as a Tool for Assessing the Effectiveness of Corporate Educational Programs

2021 ◽  
Vol 13 (4) ◽  
pp. 189-202
Author(s):  
M.M. Dmitrieva ◽  
S.V. Umnov ◽  
D.A. Podolsky
Keyword(s):  
Learning Outcomes ◽  
Training Programs ◽  
Corporate Training ◽  
Educational Programs ◽  
Assessment Method ◽  
The Self ◽  
Self Assessment ◽  
Assessment Of Learning ◽  
Before And After

The existing tools for assessing the effectiveness of educational programs differ in the degree of effectiveness, applicability, and costs. The self-assessment method, which involves the determination of the level of expression of various qualities by students of educational programs before and after graduation. The method of assessing students' own competencies has significant limitations associated with social desirability. Nevertheless, the article analyzes the possibilities of using this method to assess the effectiveness of corporate educational programs. The results of using the self-assessment method to assess the effectiveness of corporate educational programs conducted in large organizations are presented. The possibilities and limitations of using various kinds of criteria for evaluating themselves by listeners are substantiated. The conclusion is made about the possibility of using the self-assessment method in the case of the focus of educational programs on the development of meta-competencies of managers. The article provides data on the assessment of learning outcomes, discusses the potential reasons for the differences obtained in the framework of projects, as well as the possibilities and limitations of using the self-assessment method to assess the educational effect of corporate training programs.

The Automated Determination of Serum Uric Acid

1966 ◽  
Vol 12 (11) ◽  
pp. 748-766 ◽  
Author(s):  
Stanley Morgenstern ◽  
Richard V Flor ◽  
James H Kaufman ◽  
Bernard Klein
Keyword(s):  
Uric Acid ◽  
Serum Uric Acid ◽  
Enzymatic Reaction ◽  
Enzymatic Determination ◽  
Before And After ◽  
The Difference ◽  
Automated Determination ◽  
Colorimetric Reaction ◽  
Good Agreement

Abstract An automated procedure is presented for the enzymatic determination of serum uric acid on both the AutoAnalyzer and the Robot Chemist. The procedure measures as the neocuproine complex, the difference in the amount of Cu+ formed by reaction of a Cu++-alkanolamine buffered solution with serum uric acid under precisely controlled conditions before and after uricase treatment of the serum. The difference is proportional to the true serum uric acid content. The elements contributing to the enzymatic reaction, the colorimetric reaction, and the elimination of interferences were investigated. Comparison of serum uric acid values obtained by this method with those obtained by ultraviolet spectrophotometry show very good agreement.

scholarly journals DETERMINATION OF l-HISTIDINE IN NANOGRAM AMOUNTS AND THE QUESTION OF ITS OCCURRENCE IN MAST CELLS

1972 ◽  
Vol 20 (11) ◽  
pp. 917-922 ◽  
Author(s):  
DAVID I. WILKINSON ◽  
DAVID GLICK
Keyword(s):  
Mast Cells ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Peritoneal Mast Cells ◽  
Before And After ◽  
Chromatographic Detection ◽  
Rat Peritoneal Mast Cells ◽  
Rate Limiting

In an attempt to clarify the question of whether histidine is stored in the mast cell for coversion to histamine or whether the rate of conversion is rapid enough to prevent accumulation of histidine so that the rate-limiting step is the histidine uptake, it was found that no histidine was demonstrable in rat peritoneal mast cells by either quantitative analysis or paper chromatographic detection. Microadaptation of Hassall's method, based on conversion of l-histidine by histidase to urocanic acid and measurement of the latter by its absorbance at 277 nm, was made to permit determination of histidine in nanogram amounts in the presence of histamine. This adaptation was found reliable when compared with the o-phthalaldehyde method in estimation of l-histidine in serum and in insulin hydrolysate, and then it was applied to analysis of mast cells before and after l-histidine uptake in vitro. The adaptation should be generally useful in microanalysis of l-histidine in histologically and cytologically defined samples.

scholarly journals In vitro assessment of antioxidant potential and determination of polyphenolic compounds of Hedera nepalensis K. Koch

2017 ◽  
Vol 10 ◽  
pp. S3699-S3706 ◽  
Author(s):  
Laila Jafri ◽  
Samreen Saleem ◽  
Ihsan-ul-Haq ◽  
Nazif Ullah ◽  
Bushra Mirza
Keyword(s):  
Polyphenolic Compounds ◽  
Antioxidant Potential ◽  
In Vitro Assessment

scholarly journals Evaluation of physicochemical and antioxidant properties of nanosized copolymeric micelles loaded with kaempferol

Pharmacia ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 49-54
Author(s):  
Krassimira Yoncheva ◽  
Nadia Hristova-Avakumova ◽  
Vera Hadjimitova ◽  
Trayko Traykov ◽  
Petar Petrov
Keyword(s):  
Antioxidant Activity ◽  
Propylene Oxide ◽  
Encapsulation Efficiency ◽  
Antioxidant Properties ◽  
In Vitro Release ◽  
Before And After ◽  
Poly Propylene ◽  
Vitro Release

The study was focused on the evaluation of two copolymers as micellar carriers for kaempferol delivery. The copolymers comprised identical hydrophilic blocks of poly(2-(dimethylamino)ethyl methacrylate and different hydrophobic blocks of either poly(ε-caprolactone) (PDMAEMA9-b-PCL70-b-PDMAEMA9) or poly(propylene oxide) (PDMAEMA13-b-PPO69-b-PDMAEMA13). The calculation of Flory-Huggins parameters and determination of encapsulation efficiency showed that PDMAEMA-b-PCL-b-PDMAEMA copolymer possessed higher capacity for kaempferol loading. The diameter of the micelles before and after lyophilization was not changed, suggesting that the micelles could be lyophilized and redispersed before administration. The in vitro release of kaempferol from PDMAEMA-b-PPO-b-PDMAEMA micelles was faster than the release from PDMAEMA-b-PCL-b-PDMAEMA micelles, probably due to the higher affinity of kaempferol to this copolymer. Further, the higher affinity resulted in a retention of antioxidant activity of kaempferol in the presence of DPPH and KO2 radicals. Thus, PDMAEMA-PCL-PDMAEMA was considered more appropriate carrier because of the higher encapsulation efficiency and preservation of antioxidant activity of the drug.

Development of Dermatological Ointment based on Aloe arborescens juice

2021 ◽  
pp. 3617-3620
Author(s):  
Glushchenko Svetlana Nikolaevna ◽  
Mikhaylova Elena Alekseevna ◽  
Kurkin Vladimir Aleksandrovich ◽  
Kochukova Anna Alexandrovna
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Properties ◽  
Uv Spectrophotometry ◽  
Ointment Base ◽  
Aloe Arborescens ◽  
Anthracene Derivatives ◽  
Comparative Determination ◽  
Active Substances

The purpose of this study is to select the optimal ointment base for the creation of a soft dosage form, to develop methods for standardizing dermatological ointment based on Aloe arborescens juice and to study antibacterial activity. The choice of the optimal ointment base, ensuring the maximum therapeutic effect of the ointment, was made. Ointments were prepared in accordance with the physical-chemical properties of the components of the basics. The criterion for evaluating the effectiveness of the used ointment bases was the degree of release of the active substances (anthracene derivatives). During the studies, antimicrobial activity was determined in the in vitro experiment. The comparative determination of the antimicrobial activity of ointment bases and juice of Aloe arborescens was performed by direct diffusion into agar. To develop the method of quantitative determination, the absorption spectra of Aloe arborescens juice and ointment extraction with 60% ethyl alcohol were studied. The optical density of the solution on the spectrophotometer at a wavelength of 396nm was measured. The quantitative content of the total active substances in the ointment, calculated on barbaloin was determined by using UV spectrophotometry.

DETERMINATION OF PA INHIBITOR 1 (PA INHIBITOR ACTIVITY AND PA INHIBITOR 1 ANTIGEN) IN PLASMA BEFORE AND AFTER VENOUS OCCLUSION

1987 ◽  
Author(s):  
I Juhan-Vague ◽  
J Valadier ◽  
M C Alessi ◽  
J Ansaldi ◽  
M F Ailluad ◽  
...  
Keyword(s):  
Platelet Activation ◽  
Venous Occlusion ◽  
Inhibitor Activity ◽  
Post Surgery ◽  
In Vitro Activation ◽  
Before And After ◽  
High Level ◽  
Good Preparation

PA Inhibitor activity (PAIact-Verheijen’s method-U/ml) and PA Inhibitor 1 antigen (PAIlAg- Kruithof’s radioimmunoassay -ng/ml) were evaluated, on blood samples before (B) and after (A) venous occlusion (VO) (10 min) in order to analyse, in B-VO samples, the ratio (R=PAIlAg/PAIact) ' between the immunological and enzymatic material, and the change of PAIlAg levels after VO.The B-VO values (m ± SD) were determined from 111 plasmas : -86 with normal ( 12U/ml) PAIact levels = 3.7 ± 2.5 ; PAIlAg = 17.4 ± 10.1 ; R = 7.1 ± 6.2 (range 1.5 - 24 )-25 with high PAIact levels (15 post surgery, 10 obese patients)= 30.9± 19.3; PAIlAg = 75.3 ± 44.7 ; R = 2.7 ± 1.5 (range 1.3- 4.4). The correlation between the 2 dosages was r = 0.82 (p 0.01). In the 2 kinds of patients with high PAIact levels, a parallel high PAIlAg level was found. As the range of the ratio R was very large, patients were divided in 2 Groups : GrI : Normal R ( 7), n=81 (normal PAIact : n=57 ; high PAIact : n=24) and GrII : high R, n=30. The results for PAIact/PAIlAg/R were = GrI :12.6± 16.3/ 31.5±34.4/ 3.2 ± 1.5. GrII : 2.6±4.1/ 27.9 ±30.1/ 13.8±6.1. In GrII the platelet origin of inactive PAIlAg from in vitro activation of platelets could be demonstrated (high level of BTG lug/ml) in 50 % of cases. No in vitro platelet activation could be demonstrated in GrI. These results point out the necessity of a good preparation of the plasma (mainly 0-4°) for PAIlAg determination.The B and A-VO values were analysed from 60 subjects. Plasmas with in vitro activation of platelet determined by BTG levels had been discarded. No platelet activation occured with the VO. The results were not corrected with the PCV. PAIlAg B-VO/A-VO = 19.2 ± 15.1/ 26.9 ± 18.3. 36 subjects (60 % of total) had an increase in PAIlAg A-VO 20 % (mean increase = 62 %) . There was no correlation between basal values of PAIlAg and the increase after VO, and between PAIlAg increase and t-PA-Ag release. It is concluded that a weak increase of PAIlAg may occur after VO ; this increase is not parallel with t-PA release. The physiopathological significance of this increase of PAIlAg as yet to be evaluated.

Sign in / Sign up

Export Citation Format

Share Document