Encapsulation of folic acid (vitamin B9) into sporopollenin microcapsules: Physico-chemical characterisation, in vitro controlled release and photoprotection study

2021 ◽  
pp. 112271
Author(s):  
Al-Shymaa Y. Mohammed ◽  
Amro K.F. Dyab ◽  
Fouad Taha ◽  
Ahmed I.A. Abd El-Mageed
Keyword(s):  
Folic Acid ◽  
Controlled Release ◽  
Vitamin B9 ◽  
Physico Chemical

scholarly journals The Antagonism of Folate Receptor by the Integrase Inhibitor Dolutegravir: Developmental Toxicity Reduction by Supplemental Folic Acid

2019 ◽  
Author(s):  
Robert M. Cabrera ◽  
Jaclyn P. Souder ◽  
John W. Steele ◽  
Lythou Yeo ◽  
Gabriel Tukeman ◽  
...  
Keyword(s):  
Folic Acid ◽  
Folate Receptor ◽  
Developmental Toxicity ◽  
Fold Increase ◽  
Integrase Inhibitor ◽  
Hiv Integrase ◽  
Binding Studies ◽  
Childbearing Age ◽  
Vitamin B9

ABSTRACTHuman immunodeficiency virus (HIV) integrase inhibitors are increasingly being used for antiretroviral therapy (ART), and dolutegravir (DTG/Tivicay) has emerged as a leading core agent. In 2018, the Tsepamo study reported a 6- to 9-fold increase for neural tube defect (NTD) risk among the offspring of mothers receiving DTG during early gestation. Maternal folate (vitamin B9) status is the largest known modifier of NTD risk, so we evaluated folate-related mechanisms of action and the critical period for DTG developmental toxicity. Folate receptor (FOLR1) binding studies indicate DTG is a non-competitive FOLR1 antagonist at therapeutic concentrations.In vitrotesting indicates calcium (2mM) increases FOLR1-folate interactions and alters DTG-FOLR1-folate interactions and cytotoxicity. DTG does not inhibit downstream folate metabolism by dihydrofolate reductase (DHFR). Early embryonic exposure to DTG is developmentally toxic in zebrafish, and supplemental folic acid can mitigate DTG developmental toxicity. The results from these studies are expected to inform and guide future animal models and clinical studies of DTG-based ART in women of childbearing age.

scholarly journals Effect of The Ethylene Inhibitor “Agno3”, Vitamin B9 “Folic Acid” And Thiol Compound “GSH” On in Vitro Propagation of Sideritis Syriaca L. Subsp. Syriaca (Hellenic Mountain Tea of The Crete Island)

2019 ◽  
Vol 8 ◽  
pp. 1086-1103
Author(s):  
Virginia Sarropoulou ◽  
Eleni Maloupa
Keyword(s):  
Folic Acid ◽  
Shoot Multiplication ◽  
Fold Increase ◽  
Simultaneous Application ◽  
Thiol Compound ◽  
Vitamin B9 ◽  
Crete Island ◽  
Ethylene Inhibitor ◽  
Final Survival

The aim of this research was to study the effect of the ethylene inhibitor “silver nitrate (AgNO3)” and vitamin B9 "folic acid" in different concentrations combined with cytokinin BA as well as the antioxidant thiol compound “L-glutathione reduced (GSH)” in different concentrations simultaneously with auxins (IBA+NAA) on micropropagation efficiency of the endemic Sideritis syriaca L. subsp. syriaca (Hellenic mountain tea of Crete/ Malotira) using shoot tip explants. The culture medium used was the MS supplemented with 30 g/l sucrose. The simultaneous application 5 ?M AgNO3 + 2.2 ?M BA promoted best the initial shoot induction stage exhibiting 4.5 shoots/ explant and 100% shoot multiplication (5 weeks). Folic acid applied at 0.25 mg/l in combination with 0.5 mg/l BA exhibited the highest shoot multiplication percentage (90%) (4 weeks). GSH at 10 ?M with 10.7 ?M NAA + 4.92 ?M IBA gave the greatest root length (13.68 mm), at 25 ?M caused a 3-fold increase in rooting (90%) and 250 ?M GSH raised by 20% shoot multiplication (80%). An 89% final survival rate of rooted microplants to ex vitro unheated greenhouse conditions was recorded within 8 weeks period during mid-late spring. Thus, the acclimatization and hardening process was successfully completed.

Controlled Release of Metformin Hydrochloride I. In vitro Release from Physical Mixture Containing Xanthan Gum as Hydrophilic Rate Retarding Polymer

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza
Keyword(s):  
Controlled Release ◽  
Xanthan Gum ◽  
In Vitro Release ◽  
Correlation Coefficients ◽  
High Ratio ◽  
Water Soluble ◽  
Metformin Hydrochloride ◽  
Model Drug ◽  
Very High

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

THYROID STIMULATORS AND THYROID STIMULATION

1971 ◽  
Vol 66 (3) ◽  
pp. 558-576 ◽  
Author(s):  
Gerald Burke
Keyword(s):  
Regulatory System ◽  
Control Site ◽  
Thyroid Cell ◽  
Primary Control ◽  
Physico Chemical ◽  
Site Of Action ◽  
Long Acting

ABSTRACT A long-acting thyroid stimulator (LATS), distinct from pituitary thyrotrophin (TSH), is found in the serum of some patients with Graves' disease. Despite the marked physico-chemical and immunologic differences between the two stimulators, both in vivo and in vitro studies indicate that LATS and TSH act on the same thyroidal site(s) and that such stimulation does not require penetration of the thyroid cell. Although resorption of colloid and secretion of thyroid hormone are early responses to both TSH and LATS, available evidence reveals no basic metabolic pathway which must be activated by these hormones in order for iodination reactions to occur. Cyclic 3′, 5′-AMP appears to mediate TSH and LATS effects on iodination reactions but the role of this compound in activating thyroidal intermediary metabolism is less clear. Based on the evidence reviewed herein, it is suggested that the primary site of action of thyroid stimulators is at the cell membrane and that beyond the(se) primary control site(s), there exists a multifaceted regulatory system for thyroid hormonogenesis and cell growth.

Development and Evaluation of Controlled Release Mucoadhesive Tablets of Captopril

1970 ◽  
Vol 9 (3) ◽  
pp. 3318-3329
Author(s):  
Kranthi Kumar Kotta ◽  
L. Srinivas
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Xanthan Gum ◽  
Diffusion Mechanism ◽  
Matrix Tablets ◽  
Fickian Diffusion ◽  
Content Uniformity ◽  
In Vitro Drug Release ◽  
Mucoadhesive Tablets

The present investigation focuses on the development of mucoadhesive tablets of captopril which are designed to prolong the gastric residence time after oral administration. Matrix tablets of captopril were formulated using four mucoadhesive polymers namely guar gum, xanthan gum, HPMC K4M and HPMC K15M and studied for parameters such as weight variation, thickness, hardness, content uniformity, swelling index, mucoadhesive force and in vitro drug release. Tablets formulated Xanthan gum or HPMC K4M with HPMC K15M provide slow release of captopril over period of 12 hr and were found suitable for maintenance portion of oral controlled release tablets. The cumulative % of drug release of formulation F9 and F10 were 90 and 92, respectively. In vitro release from these tablets was diffusion controlled and followed zero order kinetics. The ‘n’ values obtained from the pappas-karsemeyer equation suggested that all the formulation showed drug release by non-fickian diffusion mechanism. Tablets formulated Xanthan gum or HPMC K4M with HPMC K15M (1:1) were established to be the optimum formulation with optimum bioadhesive force, swelling index & desired invitro drug release. This product was further subjected to stability study, the results of which indicated no significant change with respect to Adhesive strength and in vitro drug release study.

Complexation with Hydroxypropyl-gama-Cyclodextrin of Birch Tree Extract Physico-chemical Characterisation of their Binary Products

2008 ◽  
Vol 59 (6) ◽  
Author(s):  
Codruta Soica ◽  
Cristina A. Dehelean ◽  
Valentin Ordodi ◽  
Diana Antal ◽  
Vicentiu Vlaia
Keyword(s):  
Inclusion Complexes ◽  
Water Solubility ◽  
In Vitro Dissolution ◽  
Molar Ratio ◽  
Bark Extract ◽  
Birch Bark ◽  
Preparation Methods ◽  
Birch Tree ◽  
Physico Chemical

Birch bark contains important pentacyclic triterpens that determine an anticancer, anti-inflammatory and antiviral activity. The compounds can be extracted by simple procedures with organic solvents. The major problem of this type of triterpens is their low water solubility which can be increased by physical procedures like cyclodextrin complexation. The aim of present study was to analyse the products between birch bark extract and hydroxypropyl-g -cyclodextrin. Hydroxypropyl-g -cyclodextrin (HPGCD) was used as a host to improve its solubility in water, via inclusion complex formation. In order to obtain the inclusion complexes, 1:2 molar ratio and two preparation methods (physical mixing, kneading) were used. The inclusion complexes were analyzed by in vitro dissolution tests, thermal analysis and X-ray diffraction.

Sign in / Sign up

Export Citation Format

Share Document