Development of Risperidone PLGA Microspheres

D’Souza, Susan; Faraj, Jabar A.; Giovagnoli, Stefano; DeLuca, Patrick P.

doi:10.1155/2014/620464

Cited by 37 publications

(28 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Placebo, Risperidone, and Olanzapine PLGA microspheres were prepared by dispersing a homogenous solution of polymer and drug into an aqueous solution containing 0.35% Polyvinyl alcohol followed by solvent extraction/evaporation for 2 hours [27,28]. The solidified microspheres were recovered by filtration and dried under vacuum at room temperature for 48 hours.…”

Section: Preparation Of Microspheresmentioning

confidence: 99%

Enhanced Degradation of Lactide-co-Glycolide Polymer with Basic Nucleophilic Drugs

D’Souza

Faraj

Dorati

et al. 2015

Advances in Pharmaceutics

Self Cite

View full text Add to dashboard Cite

The purpose of this study was to examine the degradative effect of weakly basic nucleophilic drugs on a lactide-co-glycolide (PLGA) polymer in a microsphere formulation. Biodegradable PLGA microspheres of two second-generation atypical antipsychotics, Risperidone and Olanzapine, were manufactured using a solvent extraction/evaporation technique. The effect of drug content, buffer pH and temperature on polymer molecular weight and degradation, were examined via a series of experiments and compared against a control (Placebo PLGA microspheres). In comparison to Placebo microspheres, significant polymer molecular weight reduction was observed upon encapsulation of varying levels of either Risperidone or Olanzapine. There was excellent correlation between the extent of molecular weight reduction during manufacture and the amount of encapsulated drug in the microspheres. Subsequent studies on polymer degradation showed: the following (a) the Placebo and Olanzapine microspheres followed pseudo first order kinetics, (b) Risperidone microspheres exhibited biphasic degradation profiles, and (c) polymer degradation was dependent on temperature, not pH. The findings of these studies show that encapsulation of weakly basic nucleophile type drugs into PLGA can accelerate the biodegradation of the PLGA and have major implications on the design of polymeric microsphere drug delivery systems.

show abstract

Section: Preparation Of Microspheresmentioning

confidence: 99%

Enhanced Degradation of Lactide-co-Glycolide Polymer with Basic Nucleophilic Drugs

D’Souza

Faraj

Dorati

et al. 2015

Advances in Pharmaceutics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Hydrolytic degradation increases polymer hydrophilicity, that is, increase in the number of carboxylic acid end groups. As such, presence of acid end groups has a dual effect on the hydrophobic end-capped PLGA polymer in that it increases the water uptake ability of the polymer and initiates autocatalytic effects in the polymer [23]. Unlike some other polymers, PLGAs undergo a bulk polymer degradation process; that is, the rate of penetration of water (hydration) is much faster than solubilization of the polymer [41].…”

Section: Effect Of Hydration On Molecular Weightmentioning

confidence: 99%

“…Thus, lactide:glycolide ratios of 85 : 15, 65 : 35, 50 : 50, and so forth are fairly common and frequently reported in the literature [18][19][20][21][22]. Altering the copolymer composition (lactide : glycolide ratio) is a primary means to tailor drug levels in vivo for varying duration, from weeks to several months [23][24][25], leading to an improvement in patient compliance due to reduced dosing frequency [19,[26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Effect of Hydration on Physicochemical Properties of End-Capped PLGA

D’Souza

Dorati

DeLuca

2014

Advances in Biomaterials

Self Cite

View full text Add to dashboard Cite

The objective of this study was to assess the physicochemical effects of hydrating a hydrophobic end-capped poly(lactide-coglycolide) (PLGA) polymer in the liquid and vapor state. PLGA RG503 polymer was incubated at 37 ∘ C in 0.5% polyvinyl alcohol (PVA) solution and at 90% RH. Samples were withdrawn at predetermined intervals and changes to polymer properties like glass transition temperature (T g ), moisture uptake, molecular weight change, and % acid number were determined using differential scanning calorimetry, Karl Fisher titrimetry, gel permeation chromatography, and acid base titrimetry, respectively. Study results showed that T g was depressed instantaneously upon hydration, indicating that bulk water acted as a plasticizer of hydrophobic end-capped PLGA. T g values decreased to levels below the incubation temperature when hydrated in 0.5% PVA solution but not in 90% RH. The drop in T g exhibited a linear relationship ( 2 > 0.99) to the amount of water uptake by the polymer; higher moisture uptake was noted with liquid water. Removal of moisture from the polymer matrix resulted in recovery of T g , only up to a period of 14 days. Presence of water in liquid or vapor form caused a reduction in molecular weight of the polymer and a corresponding increase in % acid number over the duration of the study.

show abstract

“…The particle size of the microsphere of RLAI formulation has been reported to be between 25 and 150 micrometers [6]. It might be the differences of the composition of the suspension that contributed to the cause of the difference of the acoustic shadow on post-injection.…”

Section: Discussionmentioning

confidence: 99%

Intramuscular Diffusion Status of Risperidone and Aripiprazole Long Acting Injectable (LAI) by Ultrasonography

Yasuhara¹,

Tanioka²,

Takase³

et al. 2016

OJPsych

View full text Add to dashboard Cite

The aim of this study was to consider the characteristics of intramuscular diffusion status of risperidone and aripiprazole long acting injectable (LAI) by ultrasonography. Subjects were 40 adult subjects diagnosed with schizophrenia and treated with LAI [32 patients were risperidone LAI (RLAI) and 8 patients were aripiprazole LAI (ALAI)]. However, in this paper, only three cases (one RLAI case and 2 ALAI cases) were selected to illustrate the diffusion effects of both LAI. Dorsogluteal intramuscular (IM) injection sites were measured at prone position using the "double cross" method. Before LAI injection, the distance from the epidermis to the under-fascia (DEUF), and distance from the epidermis to the iliac bone (DEI) at the IM injection site were assessed by using ultrasonography: 1) the injection needle was inserted to the gluteus medius, and 2) observed the diffusion status within the muscle injected RLAI and ALAI were confirmed using the B-mode ultrasonography. Both RLAI and ALAI were depicted as high echogenicity with acoustic shadowing. It was considered that the diffusion states of LAIs by ultrasonography were important time course evaluations providing objective evidence.

show abstract

Development of Risperidone PLGA Microspheres

Cited by 37 publications

References 48 publications

Enhanced Degradation of Lactide-co-Glycolide Polymer with Basic Nucleophilic Drugs

Enhanced Degradation of Lactide-co-Glycolide Polymer with Basic Nucleophilic Drugs

Effect of Hydration on Physicochemical Properties of End-Capped PLGA

Intramuscular Diffusion Status of Risperidone and Aripiprazole Long Acting Injectable (LAI) by Ultrasonography

Contact Info

Product

Resources

About