摘 要:本文以提高国内渗透泵制剂产业化程度为主体思路,从解决和简化制约国内渗透泵制剂产业化的关键技术——激光打孔技术入手,应用三种新型的制剂技术(原位致孔技术、双面打孔技术和异步释放技术)分别对适合于水溶性药物和难溶性药物的三种结构的渗透泵制剂(单层渗透泵、推拉式渗透泵和三层渗透泵)进行了研究,旨在解决或简化渗透泵制剂生产中的激光打孔过程,从而使更多的渗透泵制剂迅速走向市场。
原位致孔技术可以使单层渗透泵制剂的释药孔在压片和包衣过程中自然形成,从而避免渗透泵制剂在生产过程中对激光打孔机的依赖,然而,自该技术问世以来,国内外却鲜有关于该技术的研究报道。因此,本文以水溶性药物盐酸普萘洛尔为模型药物,制备了原位致孔盐酸普萘洛尔单层渗透泵,采用单因素研究的方法从片芯处方、衣膜处方和制备工艺三个方面对影响盐酸普萘洛尔释药行为的因素进行了考察;应用相似因子法(f2)对不同处方下的释药曲线进行了比较,并在此基础上得到了最优处方;在最优处方下,对分别采用原位致孔技术和机械打孔技术制备的盐酸普萘洛尔单层渗透泵片进行了释放度考察,结果表明二者的体外释药行为相似(f2=73.6),说明采用原位致孔的方法能够达到与机械打孔方法基本相同的释药效果。
在推拉式渗透泵的生产过程中,需要向片芯中加入颜料并且结合颜色识别装置的使用以辨别出含药层和助推层,从而确保将释药孔打在含药层一侧的衣膜上。原位致孔技术虽然能够解决单层渗透泵的激光打孔问题,但却无法应用于难溶性药物所通常采用的推拉式渗透泵中。因此,本文以难溶性的格列齐特为模型药物,在传统型推拉式渗透泵的基础上,设计并制备了双面打孔型推拉式渗透泵;通过单因素研究从含药层处方、助推层处方、衣膜处方、释药孔性质、压片工艺以及体外释药条件六个方面,对影响双面打孔格列齐特推拉式渗透泵片释药行为的因素进行了详细的考察,同时,应用相似因子法对以上各种因素下双面打孔型推拉式渗透泵和传统型推拉式渗透泵释药特点的异同进行了系统的研究;在此基础上,通过对双面打孔型推拉式渗透泵含药层和助推层黏度的测定,结合流体力学中的Poiseuille层流定律方程,对双面打孔格列齐特推拉式渗透泵片的释药机理进行了较为深入的探讨。由于在双面打孔推拉式渗透泵的生产过程中,只需在片剂的两侧同时打孔即可,因此不需要颜料和颜色识别装置的使用,从而大大简化推拉式渗透泵的处方和打孔工艺。
三层渗透泵由于两个含药层分布在片芯的两侧,因此激光打孔过程中同样不需要进行颜色识别。本文的第三章中,设计并制备了一种新型的异步释放格列齐特三层渗透泵片,该三层渗透泵片能在初期几个小时内以较快的速率释放模型药物,而在随后的时间里缓慢的释放模型药物。本研究通过药动学方程的计算,预测了异步释放情况下格列齐特单剂量给药后血液中的药量,并以此为依据,设计了异步释放格列齐特三层渗透泵片中两个含药层中所载药量与各自控释时间;在此基础上,通过综合控制两个含药层的重量差异、两个含药层的黏度差异和包衣膜的厚度,对实现三层渗透泵片中两个含药层分别以不同速率释放药物的方法进行了研究。实验结果表明,通过异步释放技术的使用,可以使渗透泵制剂的释药曲线多样化,同时,该方法还可以在确保最终释药曲线不变的前提下,对三层渗透泵制剂中三个物料层的重量进行分别调节,从而得到最适合于三层压片机打片的三层渗透泵处方。
本文采用高效液相色谱法,以自制的传统型格列齐特推拉式渗透泵片为参比制剂,以自制的双面打孔格列齐特推拉式渗透泵片和异步释放格列齐特三层渗透泵片为受试制剂,对三种格列齐特渗透泵制剂进行了beagle犬体内药物动力学研究。实验中,采用三交叉设计,对6只健康beagle犬体内血药浓度进行了实际测定,单剂量给药的实验结果表明:传统型格列齐特推拉式渗透泵片、双面打孔格列齐特推拉式渗透泵片和异步释放格列齐特三层渗透泵片的血药浓度曲线下面积AUC分别为178.2±25.9、180.8±24.0和164.7±21.2(μg•h/ml);对于传统型格列齐特推拉式渗透泵片和双面打孔格列齐特推拉式渗透泵片,最大血药浓度Cmax分别为8.48±1.63和9.12±1.87(μg/ml)、达峰时间Tmax分别为10.33±0.82和10±0.00(h),而对于异步释放格列齐特三层渗透泵片,其血药浓度曲线图中并无药“峰”出现,而是以“坪”的形式出现,4~12小时之间的坪浓度约为7μg/ml。本文还对三种格列齐特渗透泵片的体内外相关性进行了评价。
关键词:原位致孔技术,双面打孔技术,异步释放技术,盐酸普萘洛尔,格列齐特,渗透泵控释制剂
Abstract:The purpose of this thesis was to improve the industrialization situation of osmotic pump dosage forms in China so that more osmotic pump products can be launched onto the market. Main works of this thesis were focused on the resolution or simplification of the limiting step in the manufacture process of osmotic pump, laser drilling. Three new technologies (in situ formed orifice technology, two sides drilling technology and differentially release technology) were applied in this study, and different types of osmotic pump (monolithic osmotic pump (MOP), push-pull osmotic pump (PPOP) and sandwiched osmotic pump (SOTs)) which were suitable for water-soluble and water-insoluble drugs were studied in this thesis.
By using of in situ formed orifice technology (ISFOT), delivery orifice of MOP can be formed automatically during tableting and coating process, thus laser drilling machine can be cast aside. Although the ability to prepare delivery orifice by ISFOT for MOP has been recognized for years, there are still few reports about the study and application of such technology. For this reason, a MOP was prepared using ISFOT in this study, and water-soluble drug propranolo hydrochloride was chosen as model drug. Influencing factors including core formulation, coating formulation and granulation method were evaluated using similarity factor (f2), and an optimal formulation was achieved based on such study. With optimal formula, the dissolution profiles of two kinds of MOP whose orifice was prepared mechanically and by ISFOT, respectively, were compared, it was found that there was no significant difference between them (f2=73.6), which meant that similar drug delivery behavior could be achieved by preparing the orifice mechanically or by use of ISFOT.
As of PPOP, it is necessary to enclose pigment in the core formula, and a color identification device is needed in the manufacture process to figure out the drug layer so that an orifice can be drilled on the drug layer side. Although the ISFOT can resolve the laser drilling process of MOP successfully, it can not be applied to PPOP. For this reason, a novel PPOP was designed and prepared using two side drilling technology (TSDT) and water-insoluble drug gliclazide was employed as model drug. Influencing factors from six aspects were studied which was drug layer formulation, push layer formulation, coating formulation, orifice properties, tableting art and dissolution conditions, respectively, and the difference between the dissolution profiles of novel PPOP and conventional PPOP was also evaluated by similarity factor (f2). Through determination of the viscosity of drug layer and push layer of the novel PPOP, the mechanism of drug release from novel PPOP was discussed by the help of Poiseuille’s law of laminar flow. As of novel PPOP, since is orifices can be drilled simply on both side surfaces, the pigment in core formula and the color identification device can be cast aside, thus simplify the core formulation and drilling process.
For sandwiched osmotic tablet system (SOTs), since its two drug layers are attached to middle push layer from two sides, it dose not need side identification in the drilling process either. In the third chapter of this thesis, a SOTs which could differentially release model drug gliclazide from two drug layers was designed and prepared, such SOTs could release model drug gliclazide at relative faster rate during the first few hours while release gliclazide at relative lower rate in the following hours. By calculating the pharmacokinetic parameters of model drug, the gliclazide amount in plasma was predicted, and according to this result, the drug distribution and controlled release period of the two drug layers were designed. Methods to achieve differentially drug release from the two drug layers were studied by adjusting the coating level and the weight, viscosity differences between the two drug layers. By using of differentially drug release technology, various drug release profiles can be obtained by SOTs, and also, the weight of three layers of SOTs can be accommodated separately with unchanged dissolution profiles, thus, optimal formula which is suitable for tri-layer tableting machine can be achieved.
Using self-made conventional PPOP as reference, relative bioavailability and pharmacokinetic study of novel PPOP and novel SOTs were performed in six beagle dogs by three-circle crossover design, drug concentration in plasma of beagle dogs after single dose oral administered of three kinds of osmotic pumps was detected by HPLC method. The results showed that the AUC of conventional PPOP, novel PPOP and SOTs was 178.2±25.9, 180.8±24.0 and 164.7±21.2 (μg•h/ml), respectively. As of conventional PPOP and novel PPOP, the Cmax were 8.48±1.63 and 9.12±1.87 (μg/ml), and Tmax were 10.33±0.82 and10±0.00 (h). While for the SOTs, the “peak” in the concentration-time curve was substituted by a platform, the concentration of the platform within 4~12h was about 7μg/ml. In this chapter, the in vitro-in vivo correlation (IVIVC) of the three osmotic pumps were also studied.
KEY WORDS: In situ formed orifice technology; two sides drilling technology; differentially release technology; propranolol hydrochloride; gliclazide; osmotic pump controlled release dosage form
第一章 原位致孔单层渗透泵片的研究
渗透泵制剂是依靠系统内外的渗透压差为释药动力将药物释放至吸收部位的给药系统。对于水溶性药物,由于其自身具有较好的溶解度,溶解后可以在片芯内形成一定的渗透压,从而提供其释放所需的释药动力,故常将水溶性药物制成结构简单的单层渗透泵片。由于水溶性药物在所有药物中占有很高的比例,因此使得水溶性药物的单层渗透泵成为最重要的一类渗透泵制剂。
激光打孔步骤是渗透泵制剂生产过程中的关键性步骤,直接影响到渗透泵制剂的质量和成本,如何避免或简化渗透泵制剂生产过程中的激光打孔环节始终是渗透泵制剂产业化的重点和难点。