In-line monitoring of a pharmaceutical blending process using FT-Raman spectroscopy.

FT-Raman spectroscopy (in combination with a fibre optic probe) was evaluated as an in-line tool to monitor a blending process of diltiazem hydrochloride pellets and paraffinic wax beads. The mean square of differences (MSD) between two consecutive spectra was used to identify the time required to obtain a homogeneous mixture. A traditional end-sampling thief probe was used to collect samples, followed by HPLC analysis to verify the Raman data. Large variations were seen in the FT-Raman spectra logged during the initial minutes of the blending process using a binary mixture (ratio: 50/50, w/w) of diltiazem pellets and paraffinic wax beads (particle size: 800-1200 microm). The MSD-profiles showed that a homogeneous mixture was obtained after about 15 min blending. HPLC analysis confirmed these observations. The Raman data showed that the mixing kinetics depended on the particle size of the material and on the mixing speed. The results of this study proved that FT-Raman spectroscopy can be successfully implemented as an in-line monitoring tool for blending processes.     

Quantitative analysis of liquid formulations using FT-Raman spectroscopy and HPLC The case of diphenhydramine hydrochloride in Benadryl

The capability of FT-Raman spectroscopy for the fast and non-destructive quantitative analysis of liquid formulations was tested and the results were compared to those obtained by HPLC. Diphenhydramine hydrochloride (DPH), the active ingredient of Benadryl, was determined in the presence of the numerous excipients of the elixir. A Raman calibration model was developed by measuring the peak intensities of different standard solutions of DPH vibration at 1003 cm(-1). Application of the calibration model on the peak intensity recorded from the as-received commercially available sample with 2.5 mg ml(-1) DPH nominal value yielded a value of 2.49+/-0.05 mg ml(-1) DPH. The reliability of this method was verified by testing it against the conventionally used HPLC. The results from both methods were in excellent agreement. The main advantage of Raman over HPLC method during routine analysis is that is considerably faster and less solvent consuming. Furthermore, Raman spectroscopy is non-destructive for the sample. On the other hand, the detection limit for Raman spectroscopy is much higher than the corresponding for the HPLC methodology.     

Influence of particle size on the quantitative determination of salicylic acid in a pharmaceutical ointment using FT-Raman spectroscopy.

A second order polynomial calibration model was developed and statistically validated for the direct and non-destructive quantitative analysis - without sample preparation - of the active pharmaceutical ingredient (API) salicylic acid in a pharmaceutical ointment using FT-Raman spectroscopy. The calibration curve was modeled by plotting the peak intensity of the vector normalized spectral band between 757 and 784cm(-1) against the known salicylic acid concentrations in standards. At this band, no spectral interferences from the ointment vehiculum (white vaseline) are observed. For the validation of the polynomial model, its fit and its predictive properties were evaluated. The validated model was used for the quantification of 25 ointments, compounded by different retail pharmacists. The same standards and samples were used, both for development and validation of a regression model and for quantitative determination by HPLC - with sample preparation - as described for the related substances of salicylic acid in the Ph. Eur. IV. The quantification results obtained by the FT-Raman method corresponded with the HPLC results (p=0.22), provided that the particle size of salicylic acid in the standards is the same as in the analyzed samples. The non-destructive FT-Raman method is a reliable alternative for the destructive HPLC method, as it is faster and does not require sample pre-treatment procedures.     

Variability in tablet fragment weights when splitting unscored cyclobenzaprine 10 mg tablets.

OBJECTIVE: To determine the weight variation and calculated dosing variability of tablet fragments upon splitting unscored cyclobenzaprine hydrochloride 10 mg tablets using two common tablet splitting devices. DESIGN: Comparative pharmaceutics study. SETTING: Pharmacy school laboratory. PARTICIPANTS: Not applicable. INTERVENTIONS: Unscored cyclobenzaprine hydrochloride 10 mg tablets from one generic manufacturer were split with a tablet splitter or a kitchen knife by a licensed pharmacist and two doctor of pharmacy students (n = 15 tablets for each method per participant). MAIN OUTCOME MEASURES: Fragment weights (FWs) were compared with the theoretical weights (TWs), which were calculated as one half of the mean weight of the tablets used in each part of the experiment; means, relative standard deviations (RSDs), and percentages of TW were also calculated. RESULTS: The mean weight before splitting the 45 tablets with the tablet splitter was 136.6 +/- 2.1 mg (TW = 68.3 mg). The mean FW after splitting was 67.9 +/- 7.9 mg. The RSD of 11.6% corresponded to a range of 69.4% to 130.2% of the TW and an estimated drug content of the split fragments between 3.47 mg and 6.51 mg. The mean weight before splitting the 45 tablets cut with a kitchen knife was 136.6 +/- 2.0 mg (TW = 68.3 mg). The mean FW was 68.0 +/- 15.7 mg with a RSD of 23.2%, corresponding to a range of 49.9% to 149.5% of the TW and an estimated drug content of the split fragments between 2.49 mg and 7.48 CONCLUSION: Tablet fragments obtained after splitting this generic cyclobenzaprine 10 mg product varied considerably in weight and estimated drug content. Accordingly, splitting cyclobenzaprine 10 mg tablets to achieve 5 mg doses could result in unpredictable dosing and therapeutic response.     

Quantification and spatial distribution of salicylic acid in film tablets using FT-Raman mapping with multivariate curve resolution

In this study, we proposed a rapid and sensitive method for quantification and spatial distribution of salicylic acid in film tablets using FT-Raman spectroscopy with multivariate curve resolution (MCR). For this purpose, the constituents of film tablets were identified by using FT-Raman spectroscopy, and then eight different concentrations of salicylic acid tablets were visualized by Raman mapping. MCR was applied to mapping data to expose the active pharmaceutical ingredients in the presence of other excipients by monitoring distribution maps and combination of FT-Raman mapping with MCR enabled the determination of lower salicylic acid concentrations. In addition, the distribution of major excipient, lactose, was examined in the tablet form. A calibration curve was obtained by plotting the intensity of the Raman signal at 1635 cm⁻¹ versus the concentration of salicylic acid and the correlation was found to be linear within the range of 0.5%–3.9% with a correlation coefficient of 0.99. The limit of detection for the technique was determined 0.35%. The ability of the technique to quantify salicylic acid in tablet test samples was also investigated.     

Development and validation of a direct, non-destructive quantitative method for medroxyprogesterone acetate in a pharmaceutical suspension using FT-Raman spectroscopy

A simple linear regression method was developed and statistically validated for the direct and non-destructive quantitative analysis—without sample preparation—of the active pharmaceutical ingredient (API) medroxyprogesterone acetate (MPA) in an aqueous pharmaceutical suspension (150 mg in 1.0 ml) using FT-Raman spectroscopy. The linear regression was modelled by plotting the highest peak intensity of the vector normalized spectral band between 1630 and 1590 cm⁻¹ against different MPA standard suspension concentrations. At this band, no spectral interferences from additives in the suspension are observed. The validated model was used for the quantification of a commercial suspension (150 mg in 1.0 ml) of the commercialized preparations. The same standards and samples were used, respectively, for the development and validation of a simple linear regression model and for the quantitative determination by means of HPLC—with sample preparation—as described for the related substances of MPA in the Ph. Eur. IV. The quantification results obtained by the FT-Raman method corresponded with the claimed label concentration (150.01 ± 0.96 mg/ml (n = 6)). Applying the HPLC method, however, a systematic error was observed (157.77 ± 0.94 mg/ml (n = 6)). The direct FT-Raman method hence appears the most reliable for the quantification of the MPA component in suspension, compared to the HPLC method that requires sample preparation. The latter method provides a systematic error because the exact volume or density of a suspension sample is unknown. A precise isolation of fixed volumes from a suspension is rather unfeasible because of the continuous sagging of the suspended particles and their sticking to the used materials in the isolation process.     

Comparative bioavailability of two tablet preparations of diltiazem in healthy volunteers.

Comparative bioavailability of two formulations of diltiazem (Dilzene, CAS 42399-41-7), a calcium antagonist, was evaluated on 10 healthy volunteers (5 males and 5 females) in a cross-over study. A single dose of 120 mg of diltiazem was administered to the volunteers in the form of either two 60-mg tablets or a 120 mg controlled-release tablet. Plasma concentrations of diltiazem over a 24-h time interval were determined by HPLC analysis. Results of this investigation demonstrate that the controlled-release formulation of diltiazem has a lower Cmax value when compared to the 60 mg conventional tablet formulation, but a longer tmax and a superimposable AUC.     

Preparation and clinical evaluation of orally-disintegrating clonidine hydrochloride tablets for preanesthetic medication

Orally-disintegrating tablets of clonidine hydrochloride, an alpha 2-adrenergic agonist, were prepared by the method of drying an aqueous suspension. The suspension was prepared using powdered lactose, and the composition ratio was 2:1 (powdered lactose: 0.048% clonidine hydrochloride solution). The suspension was dried under 4 +/- 1 degrees C (72 +/- 15% R.H.). We obtained tablets containing clonidine hydrochloride (40 micrograms/tablet). Physical properties of the tablets were as follows: hardness was 4.0 kgf, and disintegration time was 41.7 s (in vitro). In the clinical use, 8 patients, aged 1-2 year and weighing 9-11 kg, received approximately 4 micrograms/kg body weight as clonidine hydrochloride. The tablet was administered 90 min before entering the operating room. All patients were willing to accept the tablet. The quality of separation from parents, sedation and a mask acceptance were excellent on all patients. These results suggest that the orally-disintegrating tablet of clonidine hydrochloride was useful in a clinical situation for the preanesthetic medication of pediatric patients aged 1-2 year.     

In vitro and in vivo evaluation of locust bean gum and chitosan combination as a carrier for buccal drug delivery

The object of the study was to evaluate locust bean gum and chitosan in ratios of 2:3; 3:2 and 4:1 (F1, F2 and F3) as a mucoadhesive component in buccal tablets and to compare the bioavailability of a propranolol hydrochloride buccal tablet with the oral tablet in healthy human volunteers. Propranolol hydrochloride buccal tablets containing various weight ratios of locust bean gum and chitosan were prepared and coated with 5% w/v ethyl cellulose on one face, and oral tablets containing 10 mg propranolol hydrochloride alone were formulated using a direct compression technique. The strength of mucoadhesion of the tablets was quantified based on the tensile force required to break the adhesive bond between a model membrane (porcine buccal mucosa) and the test polymer. The forces of detachment for the mucoadhesive buccal tablets were 14.61 +/- 0.14, 13.21 +/- 0.13 and 11.71 +/- 0.12. An in vitro study was carried out in pH 6.8 phosphate buffer and the cumulative percentage release of propranolol measured at 10 min intervals for 600 min was found to be 98.31 +/- 0.10, 92.24 +/- 0.41 and 90.18 +/- 0.76 respectively. A bioavailability study was conducted with the prepared formulation in 16 healthy human volunteers to determine the plasma concentration of propranolol at 0, 1, 2, 3, 4, 6, 8, 10 and 12 h. The bioavailability (AUC(0-t*) ng x h/ml) of the buccal propranolol hydrochloride tablets (F1, F2 and F3) and oral tablet (F4) was found to be 2244.18 +/- 210, 3580.69 +/- 460, 3889.19 +/- 290 and 1732 +/- 96 ng x hr/ml respectively. The study indicates that locust bean gum and chitosan in a weight ratio of 2:3 (F1) not only releases the drug unidirectionally from the dosage form, but also gives buccal tablets which are sufficiently mucoadhesive for clinical applications.     

HPLC法测定乙胺吡嗪利福异烟片Ⅱ中盐酸乙胺丁醇的含量

目的:建立以高效液相色谱法测定乙胺吡嗪利福异烟片Ⅱ中盐酸乙胺丁醇含量的方法。方法:色谱柱为Alltima CN,流动相为乙腈-三乙胺的水溶液(50:50),稀释剂为Na_2HPO_4溶液,检测波长为200 nm,流速为1.0 mL·min~(-1),柱温为室温,进样量为20μL。结果:盐酸乙胺丁醇检测浓度的线性范围为100.2～601.2μg·mL~(-1)(r=0.999 98);平均回收率为99.8%,RSD= 0.374%。结论:本方法操作简单、结果准确、重现性好,可用于该制剂的质量控制。     

Content uniformity in granules for aceclofenac controlled release (CR) tablets determined using near-infrared spectroscopy and wide area illumination (WAI) raman spectroscopy

Non-destructive and rapid determination methods were developed for aceclofenac controlled release (CR) tablets. The tablet is composed of two layers, rapid release and controlled release (CR) layers. The pharmaceutical manufacturing process for CR granules is very critical for dissolution control of CR tablets. During processing, a rapid and nondestructive method to test content uniformity of aceclofenac granules is required. Chemometrics using near-infrared (NIR) and Raman spectroscopy have found significant uses in quantitative analysis of pharmaceutical products in complex matrixes. Most of the pharmaceutical products can be measured directly with little or no sample preparation using these spectroscopic methods. This study showed NIR and wide area illumination Raman spectroscopy with partial least squares (PLS) was very effective for the content uniformity of granules while high performance liquid chromatography (HPLC), a conventional method, was time-consuming and ineffective for real time control. This study showed that on-line control of content uniformity control of aceclofenac CR tablets can be achieved using NIR and Raman spectroscopy.     

盐酸乙哌立松片在健康人体内的药代动力学及生物等效性

AimTo develop a HPLC-ESI-MS assay for determination of eperisone hydrochloride in human plasma and investigate the pharmacokinetics and bioequivalence of two eperisone hydrochloride tablets in human. MethodsBuflomedil hydrochloride was used as the internal standard. After alkalized with saturated sodium bicarbonate solution, plasma was extracted with diethylether-cyclohexane (1∶1) and separated using HPLC on a reversed-phase C₁₈ column with a mobile phase of 10 mmol·L_-1 ammonium acetate buffer solution (adjusted to pH 3.88 with acetic acid)-methanol (20∶80). HPLC-ESI-MS was performed in the selected ion monitoring (SIM) mode using target ions at m/z 260 for eperisone and m/z 308 for the internal standard. A randomized crossover design was performed in 20 healthy volunteers. In the two study periods, a single 100 mg dose of each tablet was administered to each volunteer. ResultsCalibration curve was linear over the range of 0.02-20 μg·L_-1. The limit of quantification for eperisone hydrochloride in plasma was 0.02 μg·L_-1. The main pharmacokinetics parameters T_1/2, T_max and C_max were (2.7±0.4) h, (1.1±0.5) h and (2.8±2.8) μg·L_-1 for the reference tablet; (2.8±0.5) h, (1.1±0.4) h and (3±4) μg·L_-1 for the test tablet, respectively. The relative bioavalability of the test tablet was (101±13)%. ConclusionThe assay was proved to be sensitive, accurate and convenient. The two formulations were bioequivalent.     

旋光法测定盐酸地尔硫草原料及片剂中盐酸地尔硫（卓）的含量

目的：建立盐酸地尔硫（卓）原料及片剂中盐酸地尔硫（卓）含量测定方法.方法：以纯化水为溶剂,运用旋光法测定盐酸地尔硫草原料及片剂中盐酸地尔硫（卓）的含量.结果：盐酸地尔硫（卓）在5 ～ 30 mg/ml范围内浓度与旋光度呈良好的线性关系,回归方程为C =0.088 7 ＋0.976 3 X（r =0.998 7）,平均回收率为100.2％,RSD为0.56％（n=9）.结论：本方法简便易行,结果准确,可作为盐酸地尔硫（卓）原料及片剂的快速质量控制方法.     

盐酸昂丹司琼口腔崩解片的制备以及崩解时间影响因素的考察

目的考察影响盐酸昂丹司琼口腔崩解片崩解时间的因素。方法采用湿法制粒压片法制备盐酸昂丹司琼的口腔崩解片,浆法测定崩解时间,考察了口腔崩解片的硬度、交联聚维酮（PVPP）和微晶纤维素（MCC）的用量对崩解时间的影响。结果片剂硬度与崩解时间成正比,交联聚维酮和微晶纤维素的用量与崩解时间成反比。调节片剂硬度为4．6kg／mm、交联聚维酮的用量为15～20mg／片和微晶纤维素的用量为50-70mg／片,可获得较理想的崩解时间和良好的片剂性质。结论湿法制粒压片法简便易行;制备的盐酸昂丹司琼口腔崩解片符合质量要求。     

盐酸鲁拉西酮片的溶出度研究

目的:考察并比较自制盐酸鲁拉西酮片与原研片的溶出度。方法:溶出度测定采用桨法,以pH 3.8 McIlvaine缓冲溶液900 ml为溶出介质,转速为50 r/min,温度为(37±0.5)℃;采用反相高效液相色谱法测定盐酸鲁拉西酮的含量,色谱柱为C8,流动相为0.05 mol/L磷酸盐缓冲液(pH 3.0)-乙腈(60∶40),检测波长为230 nm,流速为1.2 ml/min,柱温为40℃。对5批自制片与1批原研片的溶出行为采用相似因子法和威布尔法进行评价。结果:盐酸鲁拉西酮检测质量浓度线性范围为10¹00μg/ml(r=0.999 9),平均回收率为99.88%(RSD=0.55%,n=3)。5批自制片与原研片的相似因子均大于85,威布尔法中各溶出参数比较差异无统计学意义(P>0.05)。结论:建立的溶出度测定方法简便、快速、准确、可靠;自制片与原研片体外溶出度一致。     

盐酸地尔硫爆破型脉冲控释片研究

目的以盐酸地尔硫为(diltiazem hydrochloride,DIL)模型药物,研制爆破型脉冲控释片并考察其体内外脉冲释药特性。方法以乙基纤维素和丙烯酸树脂(Eudragit L)为包衣材料,采用薄膜包衣法,制备含盐酸地尔硫60 mg的脉冲控释片。通过体外释放度实验,考察了处方因素对脉冲控释片体外释放的影响;通过吸水实验确定了脉冲控释片的释药机理;以高效液相色谱法测定8名受试者的体内血药浓度,研究脉冲控释片的体内药代动力学和生物利用度。结果片芯处方、包衣组成和包衣厚度影响盐酸地尔硫的脉冲释放。该制剂在体外延迟释放时间T₁₀为4.4 h,释放至最大的时间T_rm为8.0 h,脉冲释放时间T_rm-10为3.6 h;其体内的延迟释放时间T_lag为4.9 h,达峰时间T_max为8.0 h,从开始释放到达峰的时间T_psi为3.1 h。脉冲控释片的相对生物利用度为105%。结论盐酸地尔硫爆破型脉冲控释片在体内外都具有脉冲释放特性。     

Simultaneous determination of amiloride hydrochloride and hydrochlorothiazide in synthetic samples and pharmaceutical formulations by multivariate analysis of spectrophotometric data

The use of multivariate spectrophotometric calibration for the simultaneous analysis of synthetic samples and commercial tablet preparations containing hydrochlorothiazide (HCT) and amiloride hydrochloride (AMH) is reported. Partial least squares (PLS-1) analysis of electronic absorption spectral data allowed the rapid and accurate resolution of mixtures in which the analyte ratios were approximately 10:1, without the need of a previous separation step and without interference from other sample constituents. The method, validated by the analysis of synthetic mixtures of both drugs, where accuracy over the linear working range as well as inter- and intra-assay precision were determined, was used in the concentration ranges of 21.7-30.4 mg l(-1) for HCT and 1.8-3.0 mg l(-1) for AMH. The proposed method was successfully applied to the evaluation of the stability of the stock solutions of the analytes in MeOH-H(2)O and to the elaboration of drug dissolution profiles of commercial tablets, results being concordant with those furnished by the USP technique. The method was also employed for the determination of drug content in two different pharmaceutical formulations, providing results that were in excellent agreement with those obtained by HPLC.     

Nondestructive determination of the ambroxol content in tablets by Raman spectroscopy

We describe a method for determining the ambroxol content in tablets nondestructively. To obtain a reliable quantitative calibration, we prepared 20 pellet samples (ambroxol content: 8.30-16.25 wt.%) and acquired their Raman spectra while rotating the pellets. The spectra of the rotated samples reflected the compositional variations better than those that were recorded without rotation. To reduce both the baseline variations and the spectral noise simultaneously, the spectra were pre-processed using wavelet transformation (WT). Then, we used the normalization method before partial least-squares (PLS) regression to correct Raman intensity variation from laser power fluctuation. The achieved standard error of cross validation (SECV) was 0.30%. Two different datasets where Raman intensity was artificially changed were prepared and the corresponding spectra were quantitatively analyzed. The result was reproducible even if laser intensity was fairly changed. Additionally, two different commercial tablets were analyzed and the accuracy of measurement was better for a tablet that had the similar spectral features of the standard pellet samples. The proposed method can be utilized for the analysis of commercial tablets if standard tablets of various ambroxol concentrations that have the same chemical components including additives and the same physical shape of tablets are available.     

Characterization of different laser irradiation methods for quantitative Raman tablet assessment

Quantitative Raman spectroscopy of conventional wet granulated pharmaceutical immediate release tablets and subsequent data evaluation was investigated. Different aspects of quantitative assessment of active pharmaceutical ingredient (API) in intact tablets with special focus on sub-sampling issues were addressed. Four different geometric laser irradiance patterns were examined to study the effect of sub-sampling within the tablets. The Raman data was evaluated using both univariate and multivariate techniques. UV absorbance spectroscopy was used as a reference method. The best result in terms of prediction error was attained by irradiating a large area of the tablets. Using multivariate calibration with multiplicative signal correction (MSC) the prediction error was 1.7%. In addition, the effect of tablet density on the Raman assessment was investigated. It was found that quantitative Raman assessment of chemical content can be made insensitive to variations in tablet density corresponding to a manufacturing compression interval of 5-20 kN provided that adequate data treatment is used. A short discussion about sample heating in the context of different irradiation patterns is included with reference to previous work. In conclusion, the present study provides a platform for developing an implementation strategy for quantitative Raman spectroscopy for both laboratory analysis and process analytical technology (PAT) applications.