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1.
Int J Pharm ; 657: 124173, 2024 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-38685441

RESUMEN

Cannabidiol (CBD) suffers from poor oral bioavailability due to poor aqueous solubility and high metabolism, and is generally administered in liquid lipid vehicles. Solid-state formulations of CBD have been developed, but their ability to increase the oral bioavailability has not yet been proven in vivo. Various approaches are investigated to increase this bioavailability. This study aimed to demonstrate the enhancement of the oral bioavailability of oral solid dosage forms of amorphous CBD and lipid-based CBD formulation compared to crystalline CBD. Six piglets received the three formulations, in a cross-over design. CBD and 7 - COOH - CBD, a secondary metabolite used as an indicator of hepatic degradation, were analyzed in plasma. A 10.9-fold and 6.8-fold increase in oral bioavailability was observed for the amorphous and lipid formulations, respectively. However, the lipid-based formulation allowed reducing the inter-variability when administered to fasted animals. An entero-hepatic cycle was confirmed for amorphous formulations. Finally, this study showed that the expected protective effect of lipids against hepatic degradation of the lipid-based formulation did not occur, since the ratio CBD/metabolite was higher than that of the amorphous one.


Asunto(s)
Disponibilidad Biológica , Cannabidiol , Lípidos , Animales , Cannabidiol/farmacocinética , Cannabidiol/administración & dosificación , Cannabidiol/sangre , Cannabidiol/química , Porcinos , Administración Oral , Lípidos/química , Estudios Cruzados , Hígado/metabolismo , Composición de Medicamentos , Solubilidad , Química Farmacéutica/métodos , Masculino
3.
J Gynecol Obstet Hum Reprod ; 47(2): 81-86, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29196153

RESUMEN

BACKGROUND: Bacterial vaginosis (BV) is a recurrent disease in women despite treatment by antibiotics. This study investigated the impact of a vaginal probiotic, Lactobacillus crispatus IP174178* (Lc), on the rate of recurrence and time to recurrence. METHODS: A prospective, multi-centre, double blind, randomised phase III trial in women with at least two documented episodes of BV in the previous year (diagnosis confirmed by presence of three Amsel criteria and a Nugent score≥7), and who had been clinically cured (i.e., no Amsel criteria) after oral metronidazole treatment (1g/day×7 days). The patients were randomised to receive vaginal capsules of either Lc or placebo, once a day, for 14 days over the first two menstrual cycles and another 14 days of the same treatment for the following two menstrual cycles. The primary efficacy endpoint was the number of patients with at least one bacteriologically confirmed recurrence of BV. RESULTS: Out of 98 assessable patients (mean age 35.7 years), 78 women were evaluated (20 patients had missing data). During the treatment period, 16/39 patients (41%) had at least one recurrence in the placebo group versus 8/39 patients (20.5%) in the Lc group (P=0.0497). The time to recurrence was longer by 28% in the Lc group (3.75±0.16 months) vs. the placebo group (2.93±0.18 months) (P=0.0298). Tolerability and safety were good in both groups. CONCLUSION: In women with recurrent BV after antibiotics, treatment with Lc IP 174178 administered over four menstrual cycles, could significantly reduce the rate of recurrence and increase the time to recurrence.


Asunto(s)
Lactobacillus crispatus , Evaluación de Resultado en la Atención de Salud , Probióticos/farmacología , Prevención Secundaria/métodos , Vaginosis Bacteriana/prevención & control , Administración Intravaginal , Adulto , Método Doble Ciego , Femenino , Humanos , Probióticos/administración & dosificación , Probióticos/efectos adversos , Estudios Prospectivos
4.
Eur J Pharm Sci ; 111: 399-408, 2018 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-29032306

RESUMEN

This review describes the EMA requirements on biowaivers for additional strengths of immediate release and modified release oral solid dosage forms focused on generic applications and highlights the challenges for a simultaneous EMA and FDA submission. Some specificities of the current EMA guidelines are compared with the current FDA Guidance for Industry, with a special focus on the strength to be investigated in vivo, formulation suitability for biowaiver, and optimizing dissolution studies for additional strength biowaivers. In Europe, the same principles applied for generics may be considered for deriving the biowaivers for innovator products. Several case studies are presented to illustrate the challenges of applying for additional strength biowaivers in EMA and FDA simultaneously.


Asunto(s)
Medicamentos Genéricos , Legislación de Medicamentos , United States Food and Drug Administration/legislación & jurisprudencia , Animales , Unión Europea , Humanos , Equivalencia Terapéutica , Estados Unidos
5.
AAPS J ; 19(4): 1091-1101, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28353216

RESUMEN

The f 2 test is generally used for comparing dissolution profiles. In cases of high variability, the f 2 test is not applicable, and the Multivariate Statistical Distance (MSD) test is frequently proposed as an alternative by the FDA and EMA. The guidelines provide only general recommendations. MSD tests can be performed either on raw data with or without time as a variable or on parameters of models. In addition, data can be limited-as in the case of the f 2 test-to dissolutions of up to 85% or to all available data. In the context of the present paper, the recommended calculation included all raw dissolution data up to the first point greater than 85% as a variable-without the various times as parameters. The proposed MSD overcomes several drawbacks found in other methods.


Asunto(s)
Química Farmacéutica , Solubilidad , Análisis Multivariante , Estados Unidos , United States Food and Drug Administration
6.
Artículo en Inglés | MEDLINE | ID: mdl-27477485

RESUMEN

BACKGROUND: Short-chain fructooligosaccharides (scFOS) have beneficial effects in subjects with minor digestive complaints, but the potential mechanisms involved have not been elucidated. The aim of the study was to evaluate changes in rectal sensitivity related to the clinical effects of scFOS in a selected group of patients with irritable bowel syndrome (IBS) and rectal hypersensitivity. METHODS: In 79 IBS patients (defined by Rome III criteria) with rectal hypersensitivity (defined as discomfort threshold ≤44 g) a parallel, placebo-controlled, randomized, and double-blind study was performed to assess the effects of dietary supplementation (5 g d-1 ) with scFOS vs placebo for 4 weeks on rectal sensitivity (primary outcome: tolerance to increasing wall tension applied by a tensostat), clinical outcomes (IBS, anxiety/depression and quality of life scores) and composition of fecal microbiota. KEY RESULTS: Rectal discomfort threshold, and IBS and quality of life scores, significantly improved during treatment, but in a similar manner in both scFOS and placebo groups; a post-hoc analysis showed that the effect of scFOS on rectal sensitivity was more pronounced in constipation-predominant-IBS patients (P=.051 vs placebo). Contrary with placebo, scFOS significantly reduced anxiety scores and increased fecal Bifidobacteria (P<.05 for both) without modifying other bacterial groups. CONCLUSIONS & INTERFENCES: The effect of scFOS on anxiety may be related to modulation of the gut microbiota; demonstration of effects of scFOS on rectal sensitivity may require higher doses and may depend on the IBS subgroup.


Asunto(s)
Ansiedad/tratamiento farmacológico , Heces/microbiología , Síndrome del Colon Irritable/tratamiento farmacológico , Microbiota/fisiología , Oligosacáridos/administración & dosificación , Adulto , Ansiedad/epidemiología , Ansiedad/psicología , Método Doble Ciego , Ácidos Grasos Volátiles/administración & dosificación , Femenino , Humanos , Síndrome del Colon Irritable/epidemiología , Síndrome del Colon Irritable/psicología , Masculino , Microbiota/efectos de los fármacos , Persona de Mediana Edad , Resultado del Tratamiento
7.
AAPS J ; 18(4): 1039-46, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27116020

RESUMEN

The US-FDA recently posted a draft guideline for industry recommending procedures necessary to obtain a biowaiver for immediate-release oral dosage forms based on the Biopharmaceutics Classification System (BCS). This review compares the present FDA BCS biowaiver approach, with the existing European Medicines Agency (EMA) approach, with an emphasis on similarities, difficulties, and shared challenges. Some specifics of the current EMA BCS guideline are compared with those in the recently published draft US-FDA BCS guideline. In particular, similarities and differences in the EMA versus US-FDA approaches to establishing drug solubility, permeability, dissolution, and formulation suitability for BCS biowaiver are critically reviewed. Several case studies are presented to illustrate the (i) challenges of applying for BCS biowaivers for global registration in the face of differences in the EMA and US-FDA BCS biowaiver criteria, as well as (ii) challenges inherent in applying for BCS class I or III designation and common to both jurisdictions.


Asunto(s)
Biofarmacia/legislación & jurisprudencia , Aprobación de Drogas/legislación & jurisprudencia , Descubrimiento de Drogas/legislación & jurisprudencia , United States Food and Drug Administration/legislación & jurisprudencia , Animales , Biofarmacia/tendencias , Descubrimiento de Drogas/tendencias , Europa (Continente) , Humanos , Estados Unidos , United States Food and Drug Administration/tendencias
8.
Int J Pharm ; 505(1-2): 42-51, 2016 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-27025293

RESUMEN

The objective of this study was development of accelerated in vitro release method for peptide loaded PLGA microspheres using flow-through apparatus and assessment of the effect of dissolution parameters (pH, temperature, medium composition) on drug release rate and mechanism. Accelerated release conditions were set as pH 2 and 45°C, in phosphate buffer saline (PBS) 0.02M. When the pH was changed from 2 to 4, diffusion controlled phases (burst and lag) were not affected, while release rate during erosion phase decreased two-fold due to slower ester bonds hydrolyses. Decreasing temperature from 45°C to 40°C, release rate showed three-fold deceleration without significant change in release mechanism. Effect of medium composition on drug release was tested in PBS 0.01M (200 mOsm/kg) and PBS 0.01M with glucose (380 mOsm/kg). Buffer concentration significantly affected drug release rate and mechanism due to the change in osmotic pressure, while ionic strength did not have any effect on peptide release. Furthermore, dialysis sac and sample-and-separate techniques were used, in order to evaluate significance of dissolution technique choice on the release process. After fitting obtained data to different mathematical models, flow-through method was confirmed as the most appropriate for accelerated in vitro dissolution testing for a given formulation.


Asunto(s)
Química Farmacéutica/métodos , Ácido Láctico/química , Microesferas , Péptidos/química , Ácido Poliglicólico/química , Tampones (Química) , Liberación de Fármacos , Concentración de Iones de Hidrógeno , Concentración Osmolar , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Solubilidad , Temperatura
9.
AAPS J ; 17(1): 24-34, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25387995

RESUMEN

The in vitro-in vivo correlation (IVIVC) (Food and Drug Administration 1997) aims to predict performances in vivo of a pharmaceutical formulation based on its in vitro characteristics. It is a complex process that (i) incorporates in a gradual and incremental way a large amount of information and (ii) requires information from different properties (formulation, analytical, clinical) and associated dedicated treatments (statistics, modeling, simulation). These results in many studies that are initiated and integrated into the specifications (quality target product profile, QTPP). This latter defines the appropriate experimental designs (quality by design, QbD) (Food and Drug Administration 2011, 2012) whose main objectives are determination (i) of key factors of development and manufacturing (critical process parameters, CPPs) and (ii) of critical points of physicochemical nature relating to active ingredients (API) and critical quality attribute (CQA) which may have implications in terms of efficiency, safety, and inoffensiveness for the patient, due to their non-inclusion. These processes generate a very large amount of data that is necessary to structure. In this context, the storage of information in a database (DB) and the management of this database (database management system, DBMS) become an important issue for the management of projects and IVIVC and more generally for development of new pharmaceutical forms. This article describes the implementation of a prototype object-oriented database (OODB) considered as a tool, which is helpful for decision taking, responding in a structured and consistent way to the issues of project management of IVIVC (including bioequivalence and bioavailability) (Food and Drug Administration 2003) necessary for the implementation of QTPP.


Asunto(s)
Bases de Datos Factuales , Modelos Biológicos , Preparaciones Farmacéuticas/administración & dosificación , Disponibilidad Biológica , Química Farmacéutica/métodos , Diseño de Fármacos , Humanos , Preparaciones Farmacéuticas/química , Preparaciones Farmacéuticas/metabolismo , Proyectos de Investigación , Equivalencia Terapéutica , Estados Unidos , United States Food and Drug Administration
10.
Pharm Res ; 31(9): 2529-38, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24676770

RESUMEN

PURPOSE: In vitro in vivo correlation (IVIVC) is a biopharmaceutical tool recommended for use in formulation development. When validated, IVIVC can be used to set dissolution limits and, based on the dissolution limits, as a surrogate for an in vivo study. The purpose of this paper is to study the various methods used to fix dissolution limits. METHODS: Fixing dissolution limits is not a straightforward process; various approaches exist. The classical ±10% of dissolution limits was compared to the recommended ±10% of Cmax and AUC and to an innovative back calculation of the 90% CI. Based on simulated values the influence of the calculation method as well as of the variability of the results and pharmacokinetic processes was investigated. RESULTS: Depending upon the method, the results are different and their comparison leads to possible rules. It appears that the usage of a back calculation of a 90% CI is an accurate and advantageous method when intra-individual variability associated with the drug is low. Those findings are in accordance with the current practice of IVIVC, which is not recommended for highly variable drugs. CONCLUSIONS: The approach of using a 90% CI allows the intra-subject variability to be taken into account and fixes limits that ensure a greater chance to show acceptable BE, in case of reasonable intra-subject variability, leading to setting broader in vitro dissolution limits compared to classical solutions.


Asunto(s)
Química Farmacéutica/métodos , Algoritmos , Simulación por Computador , Modelos Químicos , Solubilidad
11.
Diabetes Obes Metab ; 14(12): 1137-44, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22988932

RESUMEN

AIMS: In this randomized, single blind, cross-over study 2.5 mg and 5 mg of the modified-release terbutaline formulation (SKP-1052) were compared with conventional immediate-release terbutaline (IRT, 5 mg) and placebo on overnight blood glucose (BG) and hypoglycaemia in 30 subjects with type 1 diabetes mellitus. METHODS: Subjects received subcutaneous injections of insulin glargine (individualized doses) before dinner. SKP-1052, IRT or placebo was administered around 21:00 hours. BG and terbutaline concentrations were monitored overnight for 10 h post-dosing. Endpoints comprised of the nadir BG (BGn 0-10 h, primary endpoint), mean overnight BG (BGmean), morning BG (BGmorning) and hypoglycaemia rates as well as pharmacokinetic (PK) endpoints. RESULTS: SKP-1052 delayed release of terbutaline by 2 h [PK-tmax (mean ± SD) 5.0 ± 2.1 h (2.5 mg) and 4.7 ± 1.7 h (5 mg) vs. 2.6 ± 1.3 h with IRT, p < 0.01, respectively]. Compared with placebo, no significant differences were observed for BGn 0-10 h across treatments, but both 5 mg formulations showed less hypoglycaemic events [10 (IRT), 16 (SKP-1052) vs. 33], higher BGmean (120, 114 and 95 mg/dl) and BGmorning (126, 126 and 101 mg/dl, all comparisons p < 0.05 vs. placebo). Numerically higher BG-levels between 3 and 8 h post-dosing were observed with 2.5 mg SKP-1052 vs. placebo. CONCLUSIONS: Compared with IRT SKP-1052 delays release of terbutaline. 2.5 mg SKP-1052 led to numerically higher BG 3 to 8 h post-dose without fasting hyperglycaemia while 5 mg SKP-1052 resulted in fasting hyperglycaemia vs. placebo. Future studies will investigate optimized doses of SKP-1052 for nocturnal hypoglycaemia prevention.


Asunto(s)
Glucemia/efectos de los fármacos , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Hiperglucemia/prevención & control , Hipoglucemia/prevención & control , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/efectos adversos , Insulina/metabolismo , Terbutalina/administración & dosificación , Adolescente , Adulto , Estudios Cruzados , Preparaciones de Acción Retardada , Diabetes Mellitus Tipo 1/sangre , Esquema de Medicación , Ayuno , Femenino , Humanos , Hipoglucemia/inducido químicamente , Inyecciones Subcutáneas , Insulina Glargina , Insulina de Acción Prolongada/administración & dosificación , Insulina de Acción Prolongada/efectos adversos , Masculino , Persona de Mediana Edad , Método Simple Ciego , Terbutalina/farmacocinética
12.
Infect Dis Obstet Gynecol ; 2012: 503648, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22701297

RESUMEN

The use of probiotics in the prevention or treatment of some vaginal infections has been the subject of numerous studies. To assess the presence of Lactobacillus casei rhamnosus (LCR35) in the vagina after an oral administration, an open randomised pilot study was conducted on 20 healthy women of child-bearing age. Materials and Methods. 2 groups of 10 women were given a 28-day oral course, that is, at least 108 CFU/day (group 1) or 2 × 108 CFU/day (group 2) of LCR35. Nugent score and vaginal screening for LCR35 were undertaken before and after 28 days of treatment. Results. The mean Nugent score decreased in group 1 (-0,2) as well as in group 2 (-0,3). 10% of women in group 1 versus 40% of women in group 2 were carrying LCR35 at the end of the trial. Conclusion. LCR35, at the minimal dose of 2 × 108 CFU/day, can return the Nugent score to normal in healthy women of child-bearing age, by means of a well-tolerated vaginal temporary presence. Phase III clinical trials will specify the preventive or curative impact of this orally administered strain on a range of vaginal disorders such as bacterial vaginosis or vulvovaginal candidiasis.


Asunto(s)
Antibacterianos/administración & dosificación , Lacticaseibacillus rhamnosus , Probióticos/administración & dosificación , Vaginosis Bacteriana/terapia , Administración Oral , Adulto , Femenino , Liofilización , Humanos , Proyectos Piloto , Vagina/microbiología , Vaginosis Bacteriana/microbiología , Adulto Joven
13.
AAPS J ; 14(3): 491-9, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22547350

RESUMEN

In vitro-in vivo correlation (IVIVC) is a biopharmaceutical tool recommended to be used in development of formulation. When validated, it can speed up development of formulation, be used to fix dissolution limits and also as surrogate of in vivo study. However, as do all tools, it presents limitations and traps. The aim of the present paper is to investigate five common traps which could limit either the setting or use of IVIVC (1) using mean or individual values; (2) correction of absolute bioavailability; (3) correction of lag time and time scaling; (4) flip-flop model; and (5) predictability corrections.


Asunto(s)
Biofarmacia , Química Farmacéutica , Área Bajo la Curva , Disponibilidad Biológica , Técnicas In Vitro , Modelos Teóricos
14.
J Anim Sci ; 86(5): 1156-63, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18203977

RESUMEN

The aim of the study was to assess the ability of a dynamic in vitro model to determine the digestibility of OM, CP, and starch compared with a validated, static, in vitro method and in vivo ileal digestibility obtained from growing pigs fitted with a T-cannula. Five experimental diets with different carbohydrate types and level were assessed: a standard corn-based diet (ST) or the same diet with coarse ground corn (CC), 8% sugar beet pulp (BP), 10% wheat bran (WB), or 8% sugar beet pulp and 10% wheat bran (HF). In the in vivo experiment, diets CC and HF reduced (P = 0.015) ileal digestibility of OM compared with the ST diet. The inclusion of sugar beet pulp reduced (P = 0.049) ileal CP digestibility of the BP diet. This reduction was not statistically significant when sugar beet pulp was combined with the wheat bran in the HF diet. No differences were shown for in vivo starch digestibility among diets. With the static in vitro method, the OM disappearance was greater than that observed in the in vivo experiment. In this static method, the BP and HF diets reduced (P = 0.004 and < 0.001, respectively) the disappearance of the OM compared with the ST diet. The coarse grinding of corn did not alter OM digestibility but decreased (P = 0.005) the starch digestibility. The R(2) between the in vivo results and the static in vitro methods for OM and starch digestibility was 0.99 when the CC diet was not considered. The dynamic in vitro model yielded OM and CP digestibility coefficients comparable with those obtained in vivo for the ST and CC diets. However, the values were considerably affected by the incorporation of the fibrous ingredients. Diets BP, WB, and HF had decreased (P = 0.009, 0.058, and 0.004, respectively) OM digestibility compared with the ST diet. Protein digestibility was also decreased (P < 0.001, P = 0.019, and P = 0.003, respectively) with the BP, WB, and HF diets compared with the ST diet. However, digestibility was decreased to a greater extent in the BP diet than in the WB and HF diets, both of which contained wheat bran. The R(2) between the dynamic in vitro model and the in vivo results for CP digestibility was 0.99 when the CC diet was not considered. No differences were detected for starch digestibility among the diets with the dynamic in vitro model. This dynamic in vitro model yielded ileal digestibility results comparable with those obtained in vivo for CP and OM with a corn-soybean diet, or with a diet including coarse corn, but it underestimated digestibility when fibrous ingredients were included in the diet.


Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales , Carbohidratos de la Dieta/administración & dosificación , Digestión , Metabolismo Energético/fisiología , Íleon/metabolismo , Porcinos/metabolismo , Alimentación Animal , Animales , Beta vulgaris , Carbohidratos de la Dieta/metabolismo , Proteínas en la Dieta/administración & dosificación , Proteínas en la Dieta/metabolismo , Relación Dosis-Respuesta a Droga , Tamaño de la Partícula , Distribución Aleatoria , Porcinos/crecimiento & desarrollo , Triticum , Zea mays
15.
Clin Pharmacol Ther ; 83(3): 413-5, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17637782

RESUMEN

Uracil-Ftorafur (UFT) combines the 5-fluorouracil (FU) prodrug tegafur with uracil (at a 1:4 molar ratio), which is a competitive inhibitor of dihydropyrimidine dehydrogenase (DPD), the limiting enzyme of FU catabolism. As a result, sustained FU concentrations are obtained in both plasma and tumor. UFT is an effective alternative to intravenous FU-Leucovorin (LV) in metastatic and adjuvant colorectal cancer treatment. A circadian rhythm for DPD activity has been shown in both human and animal studies, with consequences on FU plasma concentrations in patients receiving FU as a continuous infusion. The chronopharmacokinetics of FU has stimulated clinical trials of chronomodulated delivery schedules for floxuridine and FU infusions, suggesting that such schedules may improve the fluoropyrimidine therapeutic index. Molecular mechanisms responsible for the circadian dependence of FU pharmacodynamics include circadian rhythms in thymidylate synthase activity and DNA synthesis, as recently reported. Chronopharmacology of FU prodrugs is poorly documented. Recently, a feasibility study of chronomodulated administration of the FU oral prodrug capecitabine was reported. To our knowledge, the only study reporting on the time dependency of UFT pharmacokinetics is a phase I study by Muggia et al.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Cronoterapia/métodos , Neoplasias Colorrectales/tratamiento farmacológico , Administración Oral , Adulto , Anciano , Área Bajo la Curva , Neoplasias Colorrectales/metabolismo , Estudios Cruzados , Femenino , Fluorouracilo/administración & dosificación , Fluorouracilo/farmacocinética , Humanos , Masculino , Persona de Mediana Edad , Tegafur/administración & dosificación , Tegafur/farmacocinética , Equivalencia Terapéutica , Uracilo/administración & dosificación , Uracilo/farmacocinética
16.
J Anim Sci ; 85(10): 2699-710, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17468425

RESUMEN

The aim of this study was to develop sustained release microspheres of capsicum oleoresin as an alternative to in-feed additives. Two spray-cooling technologies, a fluidized air bed using a spray nozzle system and a vibrating nozzle system placed on top of a cooling tower, were used to microencapsulate 20% of capsicum oleoresin in a hydrogenated, rapeseed oil matrix. Microencapsulation was intended to reduce the irritating effect of capsicum oleoresin and to control its release kinetics during consumption by the animal. Particles produced by the fluidized air bed process (batch F1) ranged from 180 to 1,000 microm in size. The impact of particle size on release of capsaicin, the main active compound of capsicum oleoresin, was studied after sieving batch F1 to obtain 4 formulations: F1a (180 to 250 microm), F1b (250 to 500 microm), F1c (500 to 710 microm), and F1d (710 to 1,000 microm). The vibrating nozzle system can produce a monodispersive particle size distribution. In this study, particles of 500 to 710 microm were made (batch F2). The release kinetics of the formulations was estimated in a flow-through cell dissolution apparatus (CFC). The time to achieve a 90% dissolution value (T90%) of capsaicin for subbatches of F1 increased with the increase in particle size (P < 0.05), with the greatest value of 165.5 +/- 13.2 min for F1d. The kinetics of dissolution of F2 was slower than all F1 subbatches, with a T90% of 422.7 +/- 30.0 min. Nevertheless, because CFC systems are ill suited for experiments with solid feed and thus limit their predictive values, follow-up studies were performed on F1c and F2 using an in vitro dynamic model that simulated more closely the digestive environment. For both formulations a lower quantity of capsaicin dialyzed was recorded under fed condition vs. fasting condition with 46.9% +/- 1.0 vs. 74.7% +/- 2.7 for F1c and 32.4% +/- 1.4 vs. 44.2% +/- 2.6 for F2, respectively. This suggests a possible interaction between capsaicin and the feed matrix. Moreover, 40.4 +/- 3.9% of the total capsaicin intake in F2 form was dialyzed after 8 h of digestion when feed had been granulated vs. 32.4 +/- 1.4% when feed had not been granulated, which suggests that the feed granulation process could lead to a partial degradation of the microspheres and to a limitation of the sustained release effect. This study demonstrates the potential and the limitations of spray-cooling technology to encapsulate feed additives.


Asunto(s)
Alimentación Animal , Capsaicina/farmacocinética , Capsicum , Composición de Medicamentos/veterinaria , Porcinos/crecimiento & desarrollo , Animales , Antibacterianos/farmacología , Capsicum/química , Preparaciones de Acción Retardada , Relación Dosis-Respuesta a Droga , Tecnología de Alimentos , Tamaño de la Partícula , Extractos Vegetales/farmacocinética , Porcinos/metabolismo
17.
J Anim Sci ; 84(7): 1850-9, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16775069

RESUMEN

The aim of this study was to develop sustained release plant extracts as a potential alternative to antibiotic growth promoters for growing pigs. Pellets with a core based on microcrystalline cellulose and 3 active compounds (eugenol, carvacrol, and thymol) were prepared using rotary fluidized-bed technology. Two particle sizes were produced that had a mean size of approximately 250 and 500 mum. Results show the process was able to produce pellets with a spherical and homogenous form when 10% of the active compounds were incorporated into the core. When active compounds were increased to 20%, the pellet became stickier, and the yield decreased from 90 to 65%. Different amounts of coating in the form of an aqueous-based ethylcellulose (EC) dispersion (Surelease) were applied to the core to modify the release of active compounds. The efficacy of the coating was evaluated in vitro using a flow-through cell apparatus. The time to achieve 50 and 90% dissolution increased with the increase in particle size (P < 0.05) and the increase in EC-coating level from 10 to 20% (wt/wt; P < 0.05), indicating the ability of the process to slow release depending on particle size and the amount of polymer applied. Differences in the release of the active compounds were observed in the same formulation of pellets, except for the formulation with small 10%-EC-coated particles, in which the active compounds were rapidly dissolved (more than 85% in 15 min or less). For all other formulations, the dissolution time for eugenol was always faster than for thymol or carvacrol. The close monitoring of plant extract behavior in the gastrointestinal tract could become a key factor in the continued use of phyto-molecules as alternatives to antibiotic growth promoters and in optimizing the balance between cost and efficacy. Different microencapsulation technologies can be used, of which the rotary fluidized bed warrants consideration because of the quality of the products obtained.


Asunto(s)
Alimentación Animal , Preparaciones de Acción Retardada/química , Extractos Vegetales/química , Animales , Celulosa/química , Química Farmacéutica , Cimenos , Eugenol/química , Monoterpenos/química , Tamaño de la Partícula , Solubilidad , Timol/química
18.
Br J Clin Pharmacol ; 58(4): 345-51, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15373926

RESUMEN

AIMS: The aim of this study was to compare salivary miconazole pharmacokinetics following once daily application of bioadhesive tablets (50 or 100 mg), vs the current treatment with a gel (3 times a day, 375 mg day(-1)). METHODS: A three way cross over study was carried out in 18 healthy subjects (nine males, nine females) with a 1 week washout period between each treatment. Plasma and salivary pharmacokinetics of miconazole were assessed over a 24-h period. RESULTS: In all subjects the tablets gave higher and more prolonged salivary miconazole concentrations than the gel. Thus salivary miconazole AUC(0,24 h) was 37.2 times greater for the 100 mg tablet (90% confidence interval [CI] 22.9, 60.5) and 18.9 times greater for the 50 mg tablet (CI 11.7, 30.6) compared with the gel. Similarly, Cmax was 17.2 times greater (CI 11.8, 25.2) and 7.8 times greater (CI 5.3, 11.4) for the 100 mg tablet and 50 mg tablet, respectively. Comparison of the 100 mg and 50 mg tablets gave ratios of 2.2 and 2.0 for Cmax and AUC(0,24 h), respectively (CI 1.5, 3.2 and 1.2, 3.2). The mean time that salivary miconazole concentrations were above 0.4 micro g ml(-1) (the concentration reached 3 h after application of the oral gel according to published data) or above 1.0 microg ml(-1) (the MIC of some Candida species) was greater for both bioadhesive tablets than for the oral gel (10-14 h vs 1.5 h and 7 h vs 0.6 h). Only 19 plasma samples from eight subjects had concentrations of miconazole above 0.4 micro g ml(-1). Ten of these were taken from five subjects after administration of the gel and nine from three subjects after administration of the tablets. CONCLUSIONS: These data strongly support the further development of miconazole bioadhesive tablets as a sustained release formulation leading to improved antifungal exposure in the buccal cavity. A single daily application should improve compliance, whereas the low systemic absorption of miconazole will alleviate concerns regarding drug interactions and adverse effects.


Asunto(s)
Antifúngicos/farmacocinética , Miconazol/farmacocinética , Administración Oral , Adulto , Antifúngicos/administración & dosificación , Estudios Cruzados , Preparaciones de Acción Retardada , Femenino , Geles , Humanos , Masculino , Miconazol/administración & dosificación , Plasma , Saliva/metabolismo , Comprimidos
19.
Eur J Drug Metab Pharmacokinet ; 25(3-4): 205-11, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11420891

RESUMEN

This study compares the pharmacokinetics and bioinversion of two chemical forms of ibuprofen administered intravenously or orally. Dogs were given the free acid form of the S(+) isomer p.o. or i.v., or the racemate, as the free acid or sodium salt, p.o., in a cross-over design. The main kinetic parameters were calculated and formation and bioinversion curves plotted. The values of Cmax, Tmax and AUC were higher for the S(+) isomer. The percentage bioinversion averaged between 35-70% according to the form. This study proposes a new index for the calculation of bioinversion, independently of any i.v. administration, and confirms its self-limiting nature.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacocinética , Ibuprofeno/farmacocinética , Animales , Perros , Estereoisomerismo
20.
Eur J Drug Metab Pharmacokinet ; 23(2): 207-12, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9725483

RESUMEN

This paper gives a definition and some basic knowledge about Laboratory Information Management Systems (LIMS) as well as their impact on the organisation, the laboratory and the co-workers. The major advantages and disadvantages of LIMS are pointed out. Two practical experiences are described. The first is related to an in house development of a PC based system which has to integrate a Vax VMS system (Multichrom) and PC based analytical and analysis softwares. The second experience is dealing with the selection and implementation of a commercial package in a pharmacokinetic laboratory. In both cases the human and time aspects were important.


Asunto(s)
Sistemas de Información en Laboratorio Clínico , Sistemas de Información en Laboratorio Clínico/instrumentación , Sistemas de Información en Laboratorio Clínico/organización & administración , Sistemas de Computación , Humanos , Programas Informáticos
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