Glutaraldehyde cross-linked chitosan microspheres as a long acting biodegradable drug delivery vehicle: studies on the in vitro release of mitoxantrone and in vivo degradation of microspheres in rat muscle

Biomaterials ◽  
1995 ◽  
Vol 16 (10) ◽  
pp. 769-775 ◽  
Author(s):  
S.R. Jameela ◽  
A. Jayakrishnan
2020 ◽  
Vol 52 (11) ◽  
pp. 1265-1274
Author(s):  
Zhijuan Zhao ◽  
Xiaodong Cui ◽  
Xiaoli Ma ◽  
Zhuanhua Wang

Abstract The self-nanoemulsifying drug delivery system has shown many advantages in drug delivery. In this study, a self-nanoemulsifying drug delivery system of buckwheat flavonoids was prepared for enhancing its antioxidant activity and oral bioavailability. A nanoemulsion of buckwheat flavonoids was developed and characterized, and its antioxidant, in vitro release, and in vivo bioavailability were determined. The nanoemulsion was optimized by the central composite design response surface experiment, and its particle size, polymer dispersity index (PDI), zeta potential, morphology, encapsulation efficiency, and stability were evaluated. The antioxidant activity was tested by measuring its 2,2-diphenyl-1-picrylhydrazyl scavenging activity, hydroxyl radical scavenging activity, and superoxide anion scavenging ability. In vitro release of buckwheat flavonoids nanoemulsion showed a higher cumulative release than the suspension, and the release fitting model followed the Ritger–Peppas and Weibull models. The effective concentration of the nanoemulsion was evaluated in vivo using a Wistar rat model, and the area under the plasma concentration-time curve of the buckwheat flavonoids nanoemulsion was 2.2-fold higher than that of the buckwheat flavonoid suspension. The Cmax of the nanoemulsion was 2.6-fold greater than that of the suspension. These results indicate that the nanoemulsion is a promising oral drug delivery system that can improve the oral bioavailability to satisfy the clinical requirements.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 255
Author(s):  
Elena M. Tosca ◽  
Maurizio Rocchetti ◽  
Elena Pérez ◽  
Conchi Nieto ◽  
Paolo Bettica ◽  
...  

Health authorities carefully evaluate any change in the batch manufacturing process of a drug before and after regulatory approval. In the absence of an adequate in vitro–in vivo correlation (Level A IVIVC), an in vivo bioequivalence (BE) study is frequently required, increasing the cost and time of drug development. This study focused on developing a Level A IVIVC for progesterone vaginal rings (PVRs), a dosage form designed for the continuous delivery in vivo. The pharmacokinetics (PK) of four batches of rings charged with 125, 375, 750 and 1500 mg of progesterone and characterized by different in vitro release rates were evaluated in two clinical studies. In vivo serum concentrations and in vitro release profiles were used to develop a population IVIVC progesterone ring (P-ring) model through a direct differential-equation-based method and a nonlinear-mixed-effect approach. The in vivo release, Rvivo(t), was predicted from the in vitro profile through a nonlinear relationship. Rvivo(t) was used as the input of a compartmental PK model describing the in vivo serum concentration dynamics of progesterone. The proposed IVIVC P-ring model was able to correctly predict the in vivo concentration–time profiles of progesterone starting from the in vitro PVR release profiles. Its internal and external predictability was carefully evaluated considering the FDA acceptance criteria for IVIVC assessment of extended-release oral drugs. Obtained results justified the use of the in vitro release testing in lieu of clinical studies for the BE assessment of any new PVRs batches. Finally, the possible use of the developed population IVIVC model as a simulator of virtual BE trials was explored through a case study.


1987 ◽  
Vol 57 (02) ◽  
pp. 201-204 ◽  
Author(s):  
P Y Scarabin ◽  
L Strain ◽  
C A Ludlam ◽  
J Jones ◽  
E M Kohner

SummaryDuring the collection of samples for plasma β-thromboglobulin (β-TG) determination, it is well established that artificially high values can be observed due to in-vitro release. To estimate the reliability of a single β-TG measurement, blood samples were collected simultaneously from both arms on two separate occasions in 56 diabetic patients selected for a clinical trial. From each arm, blood was taken into two tubes containing an anticoagulant mixture with (tube A) and without (tube B) PGE!. The overall mean value of B-TG in tube B was 1.14 times higher than in tube A (p <0.01). The markedly large between-arms variation accounted for the most part of within-subject variation in both tubes and was significantly greater in tube B than in tube A. Based on the difference between B-TG values from both arms, the number of subjects with artifically high B-TG values was significantly higher in tube B than in tube A on each occasion (overall rate: 28% and 14% respectively). Estimate of between-occasions variation showed that B-TG levels were relatively stable for each subject between two occasions in each tube. It is concluded that the use of PGEi decreases falsely high B-TG levels, but a single measurement of B-TG does not provide a reliable estimate of the true B-TG value in vivo.


Author(s):  
Chukwuebuka Umeyor ◽  
Uchechukwu Nnadozie ◽  
Anthony Attama

This study seeks to formulate and evaluate a solid lipid nanoparticle-based, solidified micellar carrier system for oral delivery of cefepime. Cefepime has enjoyed a lot of therapeutic usage in the treatment of susceptible bacterial infections; however, its use is limited due to its administration as an injection only with poor patient compliance. Since oral drug administration encourage high patient compliance with resultant effect in improved therapy, cefepime was formulated as solid lipid microparticles for oral delivery using the concept of solidified micellar carrier system. The carrier system was evaluated based on particle yield, particle size and morphology, encapsulation efficiency (EE %), and thermal analysis using differential scanning calorimeter (DSC). Preliminary microbiological studies were done using gram positive and negative bacteria. In vitro release study was performed using biorelevant media, while in vivo release study was performed in white albino rats. The yield of solid lipid microparticles (SLM) ranged from 84.2 – 98.0 %. The SLM were spherical with size ranges of 3.8 ± 1.2 to 42.0 ± 1.4 µm. The EE % calculated ranged from 83.6 – 94.8 %. Thermal analysis showed that SLM was less crystalline with high potential for drug entrapment. Microbial studies showed that cefepime retained its broad spectrum anti-bacterial activity. In vitro release showed sustained release of cefepime from SLM, and in vivo release study showed high concentration of cefepime released in the plasma of study rats. The study showed that smart engineering of solidified micellar carrier system could be used to improve oral delivery of cefepime.


Author(s):  
Nagratna Dhople ◽  
P N Dandag ◽  
A P Gadad ◽  
C K Pandey ◽  
Masthiholimath V S

A gastroretentive sustained release system of itopride hydrochloride was formulated to increase the gastric residence time and modulate its release behavior. Itopride hydrochloride is a prokinetic drug used in the treatment of gastroeosophageal reflux disease, Non-ulcer dyspepsia and as an antiemetic. Hence, itopride hydrochloride beads were prepared by emulsion gelation method by employing low methoxy pectin and sodium alginate as sustained release polymers in three different ratios alone and in combination and sunflower oil was used to enable floating property to the beads. The effect of variation in polymer and their concentration was investigated. The beads were evaluated for production yield, particle size, swelling index, density measurement, buoyancy, drug content, drug entrapment efficiency, in vitro release characteristics and release kinetic study. Based on drug entrapment efficiency, buoyancy, swelling and in vitro release, F9 was selected as the optimized formulation. F9 was further subjected to surface morphology by SEM, in vitro release comparison with marketed formulation, in vivo floating study in rabbits and stability study for 90 days. In vitro release follows zero order and fitted in Korsmeyer peppas model (Non-Fickian release). Therefore, the rate of drug release is due to the combined effect of drug diffusion and polymer swelling. The in vivo X-ray studies revealed that the beads were floating in the rabbit stomach up to 10 hours. Thus, it was concluded that the sustained release formulation containing itopride hydrochloride was found to improve patient compliance, minimize the side effects and decrease the frequency of administration.


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