Site-specific oral controlled release metformin tablets - development, in vitro, ex vivo and in vivo evaluation

10.5580/1571 ◽  
2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Revathi M. ◽  
Indira Y.

This study elucidates the enhancement of the permeation of bosentan monohydrate through skin by encapsulating it in vesicles loaded transdermal delivery system. Niosomal vesicles were formulated by ether injection method. Formulation FN7 (span 60: cholesterol: poloxamer 401, 1.25:1:0.25) showed maximum entrapment efficiency of 96.7±0.037% and was optimized for loading in to transdermal system. Transdermal systems were formulated using both hydrophilic and hydrophobic polymers like HPMC, HEC and EC. Formulation F1 with HPMC was optimized based on in vitro release (99.21±1.45 %) and was further evaluated for ex-vivo permeation. The results indicate that the ex vivo release (98.13±1.65%) was as par with in vitro release and followed zero order super case- II transport mechanism. The in vivo studies were done on New Zealand male rabbits for oral and transdermal route. The results inferred no significant change in half-life of drug but a substantial difference in Tmax, AUC and MRT was observed in transdermal systems. A two fold increase in AUC was observed in transdermal route (18.609±7.251µg/ml/h) when compared to oral route (9.644±5.621µg/ml/h). A controlled release was attained up to 35h and reservoir effect was observed and this may be due to the barrier properties of skin. Drug encapsulated niosomes were released in to the skin by loosening the lipid layers and the surfactant acted as penetration enhancer. The study infers that niosomes loaded transdermal patches of bosentan monohydrate can enhance the bioavailability and provided controlled release for better therapeutic efficacy and safety of drug.


2021 ◽  
pp. 088391152199784
Author(s):  
Loveleen Kaur ◽  
Ajay Kumar Thakur ◽  
Pradeep Kumar ◽  
Inderbir Singh

Present study was aimed to synthesize and characterize Chitosan-Catechol conjugates and to design and develop mucoadhesive pellets loaded with lafutidine. SEM images indicated the presence of fibrous structures responsible for enhanced mucoadhesive potential of Chitosan-Catechol conjugates. Thermodynamic stability and amorphous nature of conjugates was confirmed by DSC and XRD studies respectively. Rheological studies were used to evaluate polymer mucin interactions wherein strong interactions between Chitosan-Catechol conjugate and mucin was observed in comparison to pristine chitosan and mucin. The mucoadhesion potential of Chitosan-Catechol (Cht-C) versus Chitosan (Cht) was assessed in silico using molecular mechanics simulations and the results obtained were compared with the in vitro and ex vivo results. Cht-C/mucin demonstrated much higher energy stabilization (∆E ≈ −65 kcal/mol) as compared to Cht/mucin molecular complex. Lafutidine-loaded pellets were prepared from Chitosan (LPC) and Chitosan-Catechol conjugates (LPCC) and were evaluated for various physical properties viz. flow, circularity, roundness, friability, drug content, particle size and percent mucoadhesion. In vitro drug release studies on LPC and LPCC pellets were performed for computing t50%, t90% and mean dissolution time. The values of release exponent from Korsmeyer-Peppas model was reported to be 0.443 and 0.759 for LPC and LPCC pellets suggesting Fickian and non-Fickian mechanism representing drug release, respectively. In vivo results depicted significant controlled release and enhanced residence of the drug after being released from the chitosan-catechol coated pellets. Chitosan-Catechol conjugates were found to be a promising biooadhesive polymer for the development of various mucoadhesive formulations.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 969
Author(s):  
Xingyi Jiang ◽  
Qinchun Rao

Fish allergy is a life-long food allergy whose prevalence is affected by many demographic factors. Currently, there is no cure for fish allergy, which can only be managed by strict avoidance of fish in the diet. According to the WHO/IUIS Allergen Nomenclature Sub-Committee, 12 fish proteins are recognized as allergens. Different processing (thermal and non-thermal) techniques are applied to fish and fishery products to reduce microorganisms, extend shelf life, and alter organoleptic/nutritional properties. In this concise review, the development of a consistent terminology for studying food protein immunogenicity, antigenicity, and allergenicity is proposed. It also summarizes that food processing may lead to a decrease, no change, or even increase in fish antigenicity and allergenicity due to the change of protein solubility, protein denaturation, and the modification of linear or conformational epitopes. Recent studies investigated the effect of processing on fish antigenicity/allergenicity and were mainly conducted on commonly consumed fish species and major fish allergens using in vitro methods. Future research areas such as novel fish species/allergens and ex vivo/in vivo evaluation methods would convey a comprehensive view of the relationship between processing and fish allergy.


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1483
Author(s):  
Emily A. Bates ◽  
John R. Counsell ◽  
Sophie Alizert ◽  
Alexander T. Baker ◽  
Natalie Suff ◽  
...  

The human adenovirus phylogenetic tree is split across seven species (A–G). Species D adenoviruses offer potential advantages for gene therapy applications, with low rates of pre-existing immunity detected across screened populations. However, many aspects of the basic virology of species D—such as their cellular tropism, receptor usage, and in vivo biodistribution profile—remain unknown. Here, we have characterized human adenovirus type 49 (HAdV-D49)—a relatively understudied species D member. We report that HAdV-D49 does not appear to use a single pathway to gain cell entry, but appears able to interact with various surface molecules for entry. As such, HAdV-D49 can transduce a broad range of cell types in vitro, with variable engagement of blood coagulation FX. Interestingly, when comparing in vivo biodistribution to adenovirus type 5, HAdV-D49 vectors show reduced liver targeting, whilst maintaining transduction of lung and spleen. Overall, this presents HAdV-D49 as a robust viral vector platform for ex vivo manipulation of human cells, and for in vivo applications where the therapeutic goal is to target the lung or gain access to immune cells in the spleen, whilst avoiding liver interactions, such as intravascular vaccine applications.


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