Preparation and evaluation of biodegradable flubiprofen gelatin micro-spheres for intra-articular administration

PURPOSE: A controlled release delivery system that localizes flurbiprofen (FP) in synovial joint is prefered to treat inflammation in rheumatoid arthritis (RA). The purpose of this study is to develop and characterize FP-loaded gelatin microspheres and evaluate FP plasma concentrations following intra-articular injection into healthy rabbits. METHODS: Flurbiprofen gelatin microspheres (FP-GMS) were prepared by a emulsion-congealing method. The RP-HPLC method was established to determine the FP concentraion in plasma. The particle size of FP-GMS with optimized formulation was 2.5 approximately 12.3 microm with a mean size of gelatin microspheres of 7.53 microm. The drug loading efficiency was 5.02% (w/w). The dissolution profile of the FP-GMS was depicted by Higuchi kinetics. RESULTS: The half time for 50% release of FP from FP-GMS (t(50)) was 5.58 h. A total of 96% original FP was remained in the microspheres after being stored under 75% humidity and 37 degrees C for 3 months. The pharmacokinetics study demonstrated that the mean resident time (MRT) of FP in the FP-GMS group was prolonged vs. the injection group significantly (p < 0.01) after intra-articular administration into healthy rabbit hind joints. The T(p) of FP-GMS group was prolonged by 2.03-times and the C(max) was decreased by 5.57-times vs. that of the injection group, respectively. The FP plasma concentration in FP-GMS was 8-fold higher than that of the FP injection group at 8 h. In addition, FP was rapidly cleared from blood circulation within 8 h with the injection group while FP was retained for more than 24 h with the FP-GMS group. CONCLUSIONS: These data indicate that the simple emulsion-congealing method can be used to encapsulate water soluble drugs such as FP for the treatment of inflammatory disease within the joint cavity.     

Development of gelatin microspheres loaded with diclofenac sodium for intra-articular administration

We have previously reported on the targeting of diclofenac sodium in joint inflammation using gelatin magnetic microspheres. To overcome complications in the administration of magnetic microspheres and achieve higher targeting efficiency, the present work focuses on the formulation of gelatin microspheres for intra-articular administration. Drug-loaded microspheres were prepared by the emulsification/cross-linking method, characterized by drug loading, size distribution, scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), X-ray diffraction (XRD), gas chromatography, and in vitro release studies. The targeting efficiency of microspheres was studied in vivo in rabbits. The microspheres showed drug loading of 9.8, 18.3, and 26.7% w/w with an average size range of 37–46 µm, depending upon the drug–polymer ratio. They were spherical in nature and free from surface drug as evidenced by the SEM photographs. FT-IR, DSC, and XRD revealed the absence of drug–polymer interaction and amorphous nature of entrapped drug. Gas chromatography confirms the absences of residual glutaraldehyde. The formulated microspheres could prolong the drug release up to 30 days in vitro. About 81.2 and 43.7% of administered drug in the microspheres were recovered from the target joint after 1 and 7 days of postintra-articular injection, respectively, revealing good targeting efficiency.     

Formulation and evaluation of flurbiprofen-loaded genipin cross-linked gelatin microspheres for intra-articular delivery

Oral and parenteral formulations are challenging to produce therapeutic concentration of flurbiprofen in the joints. This encourages for the development of formulation for long term drug retention in the joint through intra-articular (i. a.) administration. In this study, genipin cross-linked gelatin microspheres of flurbiprofen were prepared for i. a. delivery. The microspheres were prepared using emulsification-homogenization-cross-linking method by changing the experimental variables such as concentration of cross-linker, cross-linking time and cross-linking temperature. The microspheres showed drug entrapment up to 76.19% with a mean particle size range of 5.91–8.19 µm. The degree of cross-linking and water-soluble fraction were 8.27–59.33% and 12.29–81.23%, respectively. SEM confirmed smooth surface and spherical shape of the microspheres. FTIR and ¹³C-NMR confirmed cross-linking of gelatin by genipin. No chemical change in encapsulated drug was observed by FTIR and TGA. DSC and XRD indicated the molecular dispersion of drug within microspheres. Optimized microspheres could prolong the drug release for more than 108?h with anomalous transport. Histopathology confirmed the biocompatibility of microspheres in the rat (Wistar) knee joint. After 96?h of i. a. injection, significant higher amount (42.56%) of administered drug in cross-linked microspheres was recovered than uncross-linked microspheres (8.27%) confirming better drug retention efficiency (p < 0.01).     

Targeted delivery of diclofenac sodium via gelatin magnetic microspheres formulated for intra-arterial administration

In the present work, we have attempted to deliver diclofenac sodium to a target site by intra-arterial injection of gelatin magnetic microspheres and subsequent localization using an external magnet. Drug-loaded magnetic microspheres were prepared by emulsification/cross-linking method, characterized by drug loading, magnetite content, size distribution, optical microscopy, scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) analysis, differential scanning calorimetry (DSC), X-ray diffraction (XRD), absence of glutaraldehyde by gas chromatography, and in vitro release studies. The targeting efficiency and the therapeutic efficacy of microspheres were studied in vivo in rabbits. The microspheres showed drug loading of 9.1, 18.7, 24.9% w/w, magnetite content of 27.8–28.9% w/w with an average size range of 25–30.6 μm, depending upon the drug–polymer ratio. They were spherical in nature as evidenced by optical microscopy and SEM. FT-IR, DSC, and XRD studies revealed the absence of drug–polymer interaction. Gas chromatography confirmed the absence of residual glutaraldehyde. The microspheres were able to prolong the drug release over 24–30 days and the application of sonication during in vitro release study has slightly increased the release rate. After intra-arterial administration of microspheres, 77.7% of injected dose was recovered at the target site which revealed good targeting efficiency. The microspheres effectively reduced joint swelling, but lesser extent than the oral diclofenac sodium in high dose, in antigen induced arthritic rabbits without producing gastric ulceration which was observed in rabbits treated with oral diclofenac sodium.     

盐酸尼卡地平鼻粘膜用明胶微球的工艺研究

目的研究盐酸尼卡地平鼻粘膜用明胶微球的制备工艺。方法以天然可生物降解的明胶为载体材料 ,液体石蜡为油相 ,Span80为乳化剂 ,采用正交设计优化空白明胶微球制备工艺 ,用乳化法和吸附法制备了盐酸尼卡地平明胶微球。采用溶媒提取法利用HPLC测定微球中药物含量。结果所得明胶微球形态良好 ,粒径分布窄 ,所选择的HPLC法用于测定明胶微球中药物含量回收率及重现性均较好 ,乳化法制备明胶微球的包封率为 31 3% ,吸附法为 5 1 %。结论所优化制备工艺可用于盐酸尼卡地平鼻粘膜给药明胶微球的制备。     

双氯芬酸钠明胶微球的制备

目的：对双氯芬酸钠明胶微球的处方及制备工艺进行初步研究。方法：以生物降解材料明胶为载体,采用乳化交联法制备双氯芬酸钠明胶微球;单因素考察的基础上,利用正交实验设计筛选最佳处方和工艺;建立紫外分光光度法测定微囊中恩诺沙星的包封率和载药量的方法。结果：所制备的双氯芬酸钠明胶微球外形圆整,大小均匀,载药量为2.05%,包封率为37.67%。结论：获得较为满意的双氯芬酸钠明胶微球。     

胸腺肽明胶微球的制备和体外释药的特性

目的:为提高胸腺肽的生物利用度,增强疗效,制备胸腺肽的明胶微球.方法:用乳化交联法制备胸腺肽明胶微球,正交设计法筛选其最佳制备工艺,Lowry法测定药物的含量,计算微球的载药量、包封率及体外释药量.结果:微球粒径范围为1.0～30.2 μm,平均粒径为14.64 μm,平均载药量为20.20%(w/w),平均包封率为80.82%,其体外释药符合Higuchi方程,稳定性考察实验结果表明其稳定性较好.结论:本法制备的胸腺肽明胶微球粒径分布集中,粒径大小符合设计要求,体外释药有明显的缓释作用,具有良好应用前景.     

Saquinavir and ritonavir pharmacokinetics following combined ritonavir and saquinavir (soft gelatin capsules) administration

AIMS: To investigate the influence of combined ritonavir (RTV) and saquinavir (soft-gelatin capsule formulation; SQV) on systemic exposure to SQV with a view to optimizing the dosing regimen of combined RTV and SQV antiretroviral therapy. METHODS: In this open labelled, randomized, parallel group study, SQV and RTV were administered twice daily for 14 days to groups of eight healthy subjects. The two antiretrovirals were either administered alone (800 mg SQV, regimen A, and 400 mg RTV, B) or in combination at various dose levels (RTV : SQV: 400 : 400 mg, C; 300 : 600 mg, D; 200 : 800 mg, E; 300 : 800 mg, F; 400 : 800 mg, G; and 400 : 600 mg, H). Pharmacokinetic parameters of saquinavir and ritonavir were determined and adverse events, vital signs, and clinical laboratory variables recorded. RESULTS: RTV substantially increased the plasma concentration of saquinavir for all dose combinations, compared with SQV alone. Based on the primary statistical analysis there was an overall 17-, 22-, and 23-fold increase in saquinavir AUC(0,24 h) on day 14 with regimens E, F, and G, respectively (with confidence intervals of 10-30, 13-37, and 13-39). The lowest combination dose of RTV (200 : 800 mg; E) significantly increased the saquinavir AUC(0,24 h) from below 5 to 57 microg ml(-1) h, which was higher than the exposure obtained with the 400 : 400 mg twice daily regimen (i.e. 36 microg ml(-1) h). RTV also reduced intersubject variability in AUC(0,24 h) for saquinavir from 105% to 32-68%, and C(max)(0,24 h) from 124% to 30-49%. In contrast, SQV showed no clinically significant effect on the pharmacokinetics of ritonavir. The combination regimens were well tolerated, with the least number of adverse events recorded for the 200 : 800 mg (RTV : SQV) combination regimen. CONCLUSIONS: RTV significantly increases saquinavir exposure as a consequence of inhibiting SQV metabolism and possibly P-glycoprotein efflux. Pharmacokinetic and safety profiles obtained in the current study indicate that the use of a combination with a lower dose of RTV and a higher dose of SQV than the 400 : 400 mg combination frequently used in clinical practice should be further explored.     

Preparation of sodium fluoride-loaded gelatin microspheres,characterization and cariostatic studies

Sodium fluoride-loaded gelatin microspheres (NaF-GMS) were prepared using double-phase emulsified condensation polymerization. The average diameter of microspheres was (11.33?±?5.56) µm. The drug content and encapsulation efficiency were 8.80% and 76.73%, respectively. The fluoride releasing profiles of NaF-GMS in physiological saline and artificial saliva (pH 4.5, pH 6.8) showed that NaF-GMS had a sustained-release property and fluoride release rate was increased in pH 4.5 artificial saliva. Experiments conducted in rabbits’ oral cavity using NaF-GMS and NaF solution as control revealed NaF-GMS could maintain oral fluoride retention longer than NaF solution. Cariostatic abilities of NaF-GMS including demineralization prohibition in vitro, fluoride deposition in artificial dental plaque and the ability of targeting to cariogenic bacteria were investigated in artificial dental plaque. The results indicated NaF-GMS with lower fluoride concentrations could achieve equivalent cariostatic effect to the concentrated NaF solution, at the same time, could prolong fluoride retention in dental plaque. Microscopic observation showed that NaF-GMS carrying fusion protein of glucan-binding domain could adhere more bacteria than NaF-GMS and this might indicate the possibility of targeting to cariogenic bacteria when NaF-GMS were properly modified.     

注射用琥珀酰明胶的制备

目的制备注射用琥珀酰明胶,以提高其稳定性及运输贮藏的便易性。方法合成琥珀酰明胶,并用IR、1H-NMR及UV光谱方法对其进行表征,采用喷雾干燥和冷冻干燥工艺制备注射用琥珀酰明胶,同时对所制备产品的再分散性质进行了初步考察。结果合成条件为:明胶质量浓度为200 mg.L-1,琥珀酸酐质量浓度为10 mg.L-1,pH值为10,温度90℃,时间2 h。冷冻干燥法制备的注射用琥珀酰明胶与琥珀酰明胶对照品的1H-NMR、IR及UV谱图均相符。以质量浓度50 mg.L-1的甘露醇为冻干保护剂制备的产品外观蓬松饱满,复溶时间短。配成输液后渗透压为288 mmol.L-1,pH值为7.19。结论运用丁二酰化法合成琥珀酰明胶,以质量浓度50 mg.L-1甘露醇为冻干保护剂,利用冷冻干燥法可相对较稳定地制备拥有较好外观及溶解度的注射用琥珀酰明胶,且配制成输液后渗透压及pH值符合静脉用药要求。     

Preparation and evaluation of biodegradable polymeric systems for the intra-articular delivery of drugs

Colloidal suspensions of four biodegradable polymers, polylactic acid (PLA), polybutylcyanoacrylate (PBCA), gelatin (PG) and albumin (PA) were prepared within the size range 1-10 micron. In-vivo biocompatibility tests with synovial tissues were carried out to assess the irritancy of the polymers following intra-articular injection into rabbit knee joints. PLA, PBCA and PG were found to cause joint inflammation whereas PA was well tolerated by the tissues. PA microspheres may provide a means of sustaining the release and reducing the rate of clearance of drugs from the knee joint.     

In vitro evaluation and intra-articular administration of biodegradable microspheres containing naproxen sodium

The camu-camu, like many other Amazonian fruits, shows an excellent potential for use due to its high vitamin C content, and the use of these natural resources could result in greater development of the Amazonian region. Few studies have been conducted with this fruit, and such studies are necessary in order to develop the required technology to allow for its utilization, thus avoiding or at least decreasing wastage of such a rich raw material. The principle objective of this study was to develop a process for the microencapsulation of camu-camu juice, optimizing the operational conditions. The processing conditions consisted of blanching at a temperature of 95 ± 2;°C for 2 min, followed by cooling in an ice bath and juice extraction using a brush type depulper. The juice was dried with gum arabic or malt dextrin in a mini-spray dryer using an air entry temperature of between 100-160°C and wall material concentration varying between 5-35%, in accordance with a factorial experimental design. Both the air entry temperature and the amount of wall material, plus the interaction between the two, gave significant positive effects at the level of 5% probability on the yield of juice powder. The optimum conditions for juice yield and vitamin C retention were established as 15% wall material and an air entry temperature of 150°C.     

抗HIV复合制剂的制备及评价

目的:制备含有3个活性成分的抗HIV复合制剂,评价体外溶出曲线和比格犬体内药动学。方法:通过分别制粒的方法制备复合制剂,采用高效液相色谱法测定溶出度,比较复合制剂与混合单方片的溶出相似性。通过双周期交叉给药,比格犬口服复合制剂与混合单方片,采用高效液相-质谱联用方法测定拉米夫定、富马酸替诺福韦二吡呋酯和ACC007的血浆浓度,比较复合制剂与混合单方片的药动学参数。结果:复合制剂与混合单方片的3个活性成分在4种介质中的溶出曲线相似性因子f₂都>50,在比格犬血浆中的主要药动学参数无明显差异,复合制剂中拉米夫定、富马酸替诺福韦二吡呋酯和ACC007较混合单方片中的平均相对生物利用度分别为108%,91%和112%。结论:复合制剂与混合单方片的体外溶出相似,比格犬体内生物利用度等效,预示临床等效可能性高。     

肺靶向硫酸链霉素明胶微球的制备

目的:用生物可降解材料明胶制备肺靶向硫酸链霉素明胶微球.方法:用乳化法制备微球,正交试验设计考察影响制备工艺的因素,用扫描电子显微镜观察微球表面形态,用红外光谱分析确证含药微球的形成.并对所制备的硫酸链霉素明胶微球的粒径及其分布、载药量、包封率、稳定性等进行了研究.结果:微球形态圆整,药物确己存于微球中.微球的平均粒径为12.269 μm,粒径在5.0～25.0 μm的微球占总数的91.5%,达到肺靶向要求.载药量为42.6%,包封率为53.8%.最佳工艺条件重现性好.经37℃、RH75%放置3个月,其含量、外观形态及大小基本不变.结论:该微球制备工艺稳定,可用于肺靶向注射剂的研究.     

褪黑激素明胶微球剂与溶液剂鼻粘膜给药比较

目的：比较明胶微球剂与溶液剂的鼻粘膜给药。方法：通过鼻粘膜滞留时间及药物鼻粘膜吸收等实验,比较明胶微球及溶液2种给药制剂的区别。结果：明胶微球剂在鼻粘膜滞留时间明显比溶液剂长,能明显提高药物鼻粘膜吸收,并延长药物在体内滞留时间。结论：明胶微球明显提高药物鼻粘膜吸收,具有很好应用前景。     

In vitro evaluation and intra-articular administration of biodegradable microspheres containing naproxen sodium.

The dispersion of non-steroidal antiinflammatory drugs (NSAIDs) into biodegradable polymeric matrices have been accepted as a good approach for obtaining a therapeutic effect in a predetermined period of time meanwhile minimizing the side effects of NSAIDs. In the present study, it was aimed to prepare Naproxen Sodium (NS), (a NSAID) loaded microsphere formulation using natural Bovine Serum Albumin (BSA) and synthetic biodegradable polymers such as poly(lactide-co-glycolic acid) (PLGA) (50:50 MW 34,000 and 88,000 Da) for intra-articular administration, and to study the retention of the drug at the site of injection in the knee joint. NS incorporated microspheres were evaluated in vitro for particle size (the mean particle size; for BSA microspheres, 10.0 +/- 0.3 microm, for PLGA microspheres, 9.0 +/- 0.2 and 5.0 +/- 0.1 microm for MW 34,000 and 88,000 Da, respectively), yield value, drug loading, surface morphology and drug release. For in vivo studies, monoarticular arthritis was induced in the left knee joints of rabbits by using ovalbumin and Freund's Complete Adjuvant as antigen and adjuvant. A certain time (4 days) is allowed for the formation of arthritis in the knee joints, then the NS loaded microspheres were injected directly into the articular cavity. At specific time points, gamma scintigrams were obtained to determine the residence time of the microspheres in knee joints, in order to determine the most suitable formulation. This study indicated that PLGA, a synthetic polymer, is more promising than the natural type BSA microspheres for an effective cure of mono-articular arthritis in rabbits.     

Enhanced targeting efficiency of PLGA microspheres loaded with Lornoxicam for intra-articular administration

Owing to its rationale of targeting the drug to the site of action and minimizing systemic toxic effects of the drug, intra-articular drug delivery system has gained growing interests. In this study, emphasis was placed on intra-articular Lornoxicam -loaded PLGA microspheres (Lnxc-PLGA-MS) preparation and improving the targeting of lornoxicam (Lnxc) in knee joint. The microspheres were prepared by a process involving solid-in-oil-in-water(S/O/W) emulsion, and evaluated for physicochemical properties. Joint cavity′s drug leakage into systemic circulation in rabbits was examined to define the drug stagnation. Meanwhile, drug retention in synovial fluid in rats was investigated to further validate the drug targeting. The microspheres were spherical as evidenced by the SEM photographs with mean size of 7.47μm, and encapsulation efficiency was observed 82.22% along with drug loading 12.17%. DSC revealed that the drug in the microspheres existed in the phase of uncrystallization. The formulated microspheres could prolong the drug release up to 32 days in vitro. Comparing with animals injected with lornoxicam solution, the plasma drug concentration decreased in rabbits and retention time increased in rats’ synovial fluid with intra-articular injections of microspheres, revealing good targeting efficiency. In conclusion, PLGA microspheres could be used to deliver lornoxicam following intra-articular administration for enhancing targeting efficiency.     

选用优质明胶改善软胶囊的崩解

目的：解决软胶囊崩解迟缓、崩解不合格的问题。方法：从更换明胶、添加加速溶出辅料、抗氧剂三方面改进囊皮，应用胶片溶解速率法筛选囊皮处方，并进行软胶囊留样考察。结果：加入L-半胱氨酸、柠檬酸，选用优质明胶均有明显的增溶效果，选用优质明胶可解决软胶囊崩解迟缓、崩解不合格的问题。结论：不同厂家生产的明胶质量存在较大差异，选用优质明胶是改善软胶囊崩解迟缓、崩解不合格问题的关键所在。     

Notel长效微球制剂的制备和评价

目的：制备并评价Notel聚乳酸-羟基乙酸共聚物（PLGA）长效缓释微球。方法：采用乳化-溶剂挥发法制备Notel缓释微球,以载药量、包封率、体外释放为评价指标,考察高分子材料、高分子溶液浓度、硬脂酸、不同pH的聚乙烯醇（PVA）溶液等因素对微球的影响,筛选最优处方并制备微球,考察大鼠药动学及对db/db小鼠的降血糖作用。结果：按最优处方制备的微球形态圆整,平均粒径为60 μm,载药量12.5%,体外释药可达1个月。微球在大鼠体内1 h即有药物释放,第8天血药浓度达到峰值C_max（52.96±3.20） ng·mL^-1并持续释放30 d。db/db小鼠的空腹血糖浓度在1个月内有效降低。结论：Notel缓释微球作为1个月长效制剂治疗2型糖尿病（T2DM）具有良好的开发前景。     

关节腔内注射用氟比洛芬明胶微球

目的:制备关节腔注射用氟比洛芬明胶微球。方法:按均匀设计法筛选乳化冻凝法制备氟比洛芬明胶微球(FP GMS)的最佳制备工艺。结果:微球粒径范围为2.5～12.3μm,平均粒径为7.53μm,氟比洛芬含量为5.02%(w/w)。其体外释药符合Higuchi方程,稳定性实验表明,FP-GMS的稳定性良好,兔关节腔内注射后,与溶液剂对照组相比氟比洛芬体内平均驻留时间(MRT)显著延长(P<0.01),峰时比对照组延长2.03倍,峰浓度比对照组减小5.57倍。体内外相关性研究表明,FP-GMS体外累积溶出百分率与兔体内药物吸收分数呈显著相关(P<0.01)。结论:本法制备的氟比洛芬明胶微球粒径分布集中,粒径大小符合设计要求,体内外释药结果表明氟比洛芬明胶微球具有明显的缓释作用。