Long-term Effects of Terminalia chebula Retz. on Hyperglycemia and Associated Hyperlipidemia, Tissue Glycogen Content and in Vitro Release of Insulin in Streptozotocin Induced Diabetic Rats

2007 ◽  
Vol 115 (10) ◽  
pp. 641-646 ◽  
Author(s):  
Y. Murali ◽  
P. Anand ◽  
V. Tandon ◽  
R. Singh ◽  
R. Chandra ◽  
...  
Keyword(s):  
Glycogen Content ◽  
In Vitro Release ◽  
Diabetic Rats ◽  
Terminalia Chebula ◽  
Long Term Effects ◽  
Vitro Release

Long-term effects of a gonadotrophin-releasing hormone agonist ([d-Ser(But)6]GnRH(1–9)nonapeptide-ethylamide) on gonadotrophin secretion from human pituitary gonadotroph cell adenomas in vitro

1988 ◽  
Vol 118 (3) ◽  
pp. 491-496 ◽  
Author(s):  
M. Daniels ◽  
P. Newland ◽  
J. Dunn ◽  
P. Kendall-Taylor ◽  
M. C. White
Keyword(s):  
Gnrh Agonist ◽  
In Vitro Release ◽  
Long Term Effects ◽  
Human Pituitary ◽  
Α Subunit ◽  
Releasing Hormone ◽  
Gonadotrophin Secretion ◽  
Gonadotrophin Releasing Hormone

ABSTRACT We have studied the effects of TRH and native gonadotrophin-releasing hormone (GnRH), and of a GnRH agonist (Buserelin; [d-Ser(But)6]GnRH(1–9) nonapeptide-ethylamide), on LH, FSH, α subunit and LH-β subunit secretion from three human gonadotrophin-secreting pituitary adenomas in dispersed cell culture. During a 24 h study, treatment with 276 nmol TRH/1 resulted in a significant (P < 0·05) stimulated release of FSH and α subunit from all three adenomas, and LH from the two adenomas secreting detectable concentrations of this glycoprotein; treatment with 85 nmol GnRH/l significantly (P < 0·05) stimulated the release of α subunit from all three, but FSH from only two and LH from only one adenoma. During a long-term 28-day study, basal FSH and α subunit concentrations were maintained, but secretion of LH, and LH-β (detectable from one tumour only), declined with time from two of the three adenomas. Addition of Buserelin to the cultures resulted in the continuous (P < 0·05) stimulation of α subunit secretion from all three adenomas, and of LH and FSH from two, whilst a transient stimulatory effect on LH and FSH secretion was seen from a third adenoma, with subsequent secretion rates declining towards control values. These data show that human gonadotrophin-secreting adenomas demonstrate variable stimulatory responses to hypothalamic TRH and GnRH, and that during chronic treatment with a GnRH agonist the anticipated desensitizing effect of the drug was not observed in two out of three adenomas studied. The mechanism for this is not clear, but such drugs are unlikely to be of therapeutic value in the management of gonadotrophin-secreting tumours. The data also suggest that GnRH and GnRH agonists have a differential effect on the in-vitro release of intact gonadotrophins and the common α subunit. J. Endocr. (1988) 118, 491–496

Fixed Speed Release System: Huperzine a Loaded Microspheres in Thermosensitive Methylcellulose Based Hydrogel

2011 ◽  
Vol 236-238 ◽  
pp. 2491-2494
Author(s):  
Rui Sun ◽  
Si Hao Chen ◽  
Chen Chen Xing
Keyword(s):  
In Vitro Release ◽  
Huperzine A ◽  
Injection System ◽  
Release System ◽  
In Situ Hydrogel ◽  
The Difference ◽  
Vitro Release

Huperzine A loaded microspheres are prepared using a W/O solvent evaporation method. The fixed speed release system is that microspheres composed with thermosensitive methylcellulose based hydrogel. SEM is used to analysis the surface morphology of Huperzine A loaded microspheres, which is shown that the difference of the size of microspheres. The size less than 200µm can be used as injection. Gelation experiment shows that the methylcellulose based solution can be transformed into in-situ hydrogel in 15 minutes at body temperature. The result of in vitro release shows that Huperzine A released in a nearly fixed speed. All the meterials of experiment can be biodegrated completely without operating to remove the gel. This is a promising long-term injection system, which is security and controlable for clinic.

scholarly journals TRIVALENT ION CROSS-LINKED AND ACETALATED GELLAN GUM MICROSPHERES OF GLIMEPIRIDE

2020 ◽  
pp. 66-68
Author(s):  
SUDIPTA DAS ◽  
RIMI DEY
Keyword(s):  
In Vitro Release ◽  
Microscopic Analysis ◽  
Entrapment Efficiency ◽  
Stability Study ◽  
Release Profile ◽  
Gellan Gum ◽  
Long Term Stability ◽  
Vitro Release

Objectives: A novel formulation was developed with glimepiride loaded trivalent ion Al+3 cross-linked and acetalated gellan gum microspheres. Methods: The glimepiride loaded microspheres were formulated using sodium alginate and gellan gum. Cross-linking agents used for the microspheres were aluminum chloride (AlCl3) and glutaraldehyde (GA). The evaluation processes of prepared microspheres were carried out by in-vitro release study, swelling index, microscopic analysis, and entrapment efficiency. Results: All the formulations show good entrapment efficiency and the maximum entrapment 84.6% was governed by the formulation (F3) cross-linked by AlCl3 and GA and their obtained mean particle size were 12.46±3.21 μm. Release profile of the formulations revealed the sustained design of the drug, particularly this formulation (F3), releasing approximately 40% over 4 h. Conclusions: From this experiment, it can be accustomed that F3 possesses higher standard formulation than the rest due to good release profile and entrapment efficiency. Therefore, the long term stability study is required for future development of this formulation.

Fabrication, characterization and long-term in vitro release of hydrophilic drug using PHBV/HA composite microspheres

2007 ◽  
Vol 61 (4-5) ◽  
pp. 1071-1076 ◽  
Author(s):  
Yingjun Wang ◽  
Xudong Wang ◽  
Kun Wei ◽  
Naru Zhao ◽  
Shuhua Zhang ◽  
...  
Keyword(s):  
In Vitro Release ◽  
Composite Microspheres ◽  
Hydrophilic Drug ◽  
Vitro Release

scholarly journals In-vitro release and oral bioactivity of insulin in diabetic rats using nanocapsules dispersed in biocompatible microemulsion

2002 ◽  
Vol 54 (4) ◽  
pp. 473-480 ◽  
Author(s):  
Suchat Watnasirichaikul ◽  
Thomas Rades ◽  
Ian G. Tucker ◽  
Nigel M. Davies
Keyword(s):  
In Vitro Release ◽  
Diabetic Rats ◽  
Vitro Release

Emulsified Sol-Gel Microspheres for Controlled Drug Delivery

2007 ◽  
Vol 330-332 ◽  
pp. 1025-1028
Author(s):  
Shula Radin ◽  
T.L. Chen ◽  
Paul Ducheyne
Keyword(s):  
Controlled Release ◽  
Room Temperature ◽  
Sol Gel ◽  
In Vitro Release ◽  
Processing Parameters ◽  
Short Term ◽  
Acid Catalyzed ◽  
Vitro Release

Controlled release silica sol-gels are room temperature processed, porous, resorbable, and biocompatible materials. Many molecules including drugs, proteins, and growth factors can be released from sol-gels, and the quantity and duration of the release can vary widely. Processing parameters render these release properties exquisitely versatile [1]. The synthesis of controlled release sol-gels involves several steps: an acid-catalyzed hydrolysis to form a sol with the molecules included, followed by casting, aging, and drying. Additional steps such as grinding and sieving are required to produce sol-gel granules of a desirable size. In this study, we focus on the synthesis of controlled release sol-gel microspheres by using a novel process, which involves only two steps:sol formation followed by emulsification. Sol-gel microspheres containing either vancomycin (antibiotic) or bupivacaine (analgesic) were successfully synthesized via this synthesis route. Both drugs showed controlled, load-dependent and time-dependent release from the microspheres. The in vitro release properties of sol-gel microspheres were different from those of sol-gel granules produced by grinding and sieving. In comparison to a fast, short-term release from the granules, the release from the microspheres was slower and of longer duration. In addition, the degradation rate of microspheres was significantly slower than that of the granules. These data enable the use of sol-gel powders for controlled long-term release.

scholarly journals Recent Progress in Drug Release Testing Methods of Biopolymeric Particulate System

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1313
Author(s):  
Yejin Kim ◽  
Eun Ji Park ◽  
Tae Wan Kim ◽  
Dong Hee Na
Keyword(s):  
Drug Release ◽  
In Vitro Release ◽  
Testing Methods ◽  
In Vitro Drug Release ◽  
Particulate System ◽  
Vitro Release ◽  
Release Testing

Biopolymeric microparticles have been widely used for long-term release formulations of short half-life chemicals or synthetic peptides. Characterization of the drug release from microparticles is important to ensure product quality and desired pharmacological effect. However, there is no official method for long-term release parenteral dosage forms. Much work has been done to develop methods for in vitro drug release testing, generally grouped into three major categories: sample and separate, dialysis membrane, and continuous flow (flow-through cell) methods. In vitro drug release testing also plays an important role in providing insight into the in vivo performance of a product. In vitro release test with in vivo relevance can reduce the cost of conducting in vivo studies and accelerate drug product development. Therefore, investigation of the in vitro–in vivo correlation (IVIVC) is increasingly becoming an essential part of particulate formulation development. This review summarizes the principles of the in vitro release testing methods of biopolymeric particulate system with the recent research articles and discusses their characteristics including IVIVC, accelerated release testing methods, and stability of encapsulated drugs.

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