Int J App Pharm, Vol 16, Issue 5, 2024, 388-394Original Article
VALIDATED REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR THE ESTIMATION OF TETRABENAZINE IN SELF-NANO EMULSIFYING DRUG DELIVERY SYSTEMS
SHASHI, NARENDRA KUMAR PANDEY*, BIMLESH KUMAR, SACHIN KUMAR SINGH, DILEEP SINGH BAGHEL, KALVATALA SUDHAKAR, SAURABH SINGH
School of Pharmaceutical Sciences, Lovely Professional University, Punjab-144411, India
*Corresponding author: Narendra Kumar Pandey; *Email: herenarendra4u@gmail.com
Received: 09 Feb 2024, Revised and Accepted: 03 Jul 2024
ABSTRACT
Objective: Self-Nano-Emulsifying Drug Delivery System (SNEDDS) of tetrabenazine (TBZ) was analysed using reverse-phase high-performance liquid chromatography.
Methods: Optimized chromatographic condition was consisted of Acetonitrile (ACN) and 0.1% v/v formic acid in the ratio of 90:10 as a mobile phase in isocratic mode at 25±1 °C. In this C-18 (250 mm×4.6 mm, 5 µm) column was used and absorbance was recorded at 283 nm.
Results: The compound was eluted at a flow rate of 1.0 ml/min and retention time (RT) was observed as 4.34±0.03 min. TBZ showed linearity over 2-10 µg/ml conc. and the value of regression was obtained as 0.9992. The developed method was found precise due to Percentage Relative Standard Deviation (%RSD) was less than 2 %. On the other hand, 0.31 and 0.96 were investigated value for Limit of Detection (LOD) and Limit of Quantification (LOQ), respectively.
Conclusion: The method adopted was found to be robust and can be apply for the determination of drug in different oil, surfactants and co-surfactants for the calculation of drug loading of pharmaceutical product formulation.
Keywords: Tetrabenazine, HPLC, Analytical method development, SNEDDS
© 2024 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/)
DOI: https://dx.doi.org/10.22159/ijap.2024v16i5.50489 Journal homepage: https://innovareacademics.in/journals/index.php/ijap
INTRODUCTION
TBZ, a BCS class IV drug, is used to treat chorea due to Huntington's disease and symptomatic treatment of hyperkinetic movement disorders. The exact mechanism of action of TBZ is unknown. It is believed to inhibit Vesicular Monoamine Transporter type 2 (VMAT-2) and it causes a depletion of neuroactive peptides like serotonin, dopamine, norepinephrine [1]. TBZ is a derivative of hexahydro-dimethoxy-benzoquinolizine, and chemically is 9,10-dimethoxy-3-isobutyl-1,3,4,6,7,11b-hexahydro-2H-pyrido[2,1-a] isoquinoline-2-one [2] (fig. 1).
Fig. 1: Structure of TBZ
TBZ depletes monoamines from nerve terminals reversibly. It reduces uptake of monoamines by inhibiting VMAT2, within synaptic vesicles of monoamine pool [3]. It is practically insoluble and undergoes first-pass metabolism [4]. To overcome these problems TBZ loaded self-nano-emulsifying drug delivery system was formulated. Lipid-based formulation approaches have significantly improved the solubility of lipophillic drugs, hence increasing oral bioavailability [5]. SNEDDS are the isotropic mixture of oil, surfactant and co-surfactant, which immediately form oil in water nano-emulsions of 20-200 nm, when diluted in water under disturbance [6]. It requires less amount of drug as compared to other conventional forms. In the Gastro-Intestinal Tract (GIT), because of its self-emulsification process, the drug is present in nano globule form, which enhances its dissolution by providing a large area and provides stability to the drug [7]. It offers stable thermodynamic formulation, improving lymphatic transport and avoiding first-pass metabolism [8].
As previously reported methods of reverse phase high-performance liquid chromatography are available, Reza Mehvar et al., 1986 developed a method in rat and human plasma with water, acetonitrile, acetic acid and triethyl amine as mobile phase in the ratio of 65:33:2.0:0.15 with 0.6 ml/min flow rate and 10 min retention time [9]. As four mobile phase was used in reported method made it complicated and time-consuming. Derangula et al., 2012 reported liquid chromatography-tandem mass spectrometric in human plasma with acetonitrile and 5 mmol ammonium acetate as mobile phase in the ratio of 60:40 with 0.8 ml/min with 2.5 min retention time [1]; this method is not reproducible. To overcome these problems, there is need to develop accurate, precise, simple RP-HPLC method which is less time-consuming and affordable for TBZ.
The aim of the performed study was to develop and validate a simple, precise, sensitive and RP-HPLC procedure to quantify the drug during pre-formulation and formulation studies.
MATERIALS AND METHODS
Materials
TBZ was gifted from Synnat Pharma Pvt. Ltd., India. Olive Oil, Cotton seed oil, Peanut oil, Paraffin oil, and Eucalyptus oil were purchased from CDH Pvt. Ltd, India. Capryol 90, Capmul MCM, Isopropyl myristate, Capryol PGMC, Labrafil M 1944 CS, Labrasol, Labrafac WL 1349, Labrafac PG, Peceol, Lauroglycol 90, Lauroglycol FCC, Transcutol P, Transcutol HP, Plurol Oleique, and Maisine CC were procured as a gift sample from Gattefosse, Mumbai, India. Tween 20, Tween 60, Tween 80, Span 80, PEG 400, and acetonitrile HPLC grade were purchased from Merck, Mumbai, India. Formic acid, Orthophosphoric acid, and Triethylamine were recieved from LOBA CHEMIE Pvt. Ltd., Mumbai, India.
Formulation development
In a glass tube, 100 µl** of capmule PGMC, 600 µl** of tween 20 and 300 µl** of transcutol P were added and vortexed for 5 min. Then, 12.5 mg of TBZ was added to the formulation and vortex until a monophasic system is formed. Add this mixture to 500 ml water at room temp. while stirring [10]. Prepared SNEDDS were stored at room temperature for further characterization. Formulations were characterized for globule size, zeta potential, and Poly-Dispersity Index (PDI).
Analytical method development
Chromatographic conditions and equipment’s
HPLC analysis was carried out using HPLC (instrument from Shimadzu Japan) equipped with a pumping system of LC-20 AD series, a PDA detector (SPDM20A; Shimadzu, Japan), and manual Rheodyne injector (20 µl** loop size). LC Solutions software was used for data processing and interpretation. Sonicator was employed to degas the mobile phase. Calibrated pH meter was used to measure the pH of prepared formic acid. For estimation of the drug, the stationary phase used was C-18 reversed-phase column (C18, 250 mm×4.6 mm, 5 µm), and the various mobile phases used for the developing method were ACN,-5 mmol ammonium acetate; ACN-0.1% glacial acetic acid; ACN-0.1% ortho-phosphoric acid and ACN-0.1% formic acid by varying their pH and mobile phase ratio. Amongst these, the selected mobile phase consists of a mixture of formic acid with pH 3.2 and ACN (10:90 v/v). The flow rate was fixed to 1 ml/min. The column temperature was ambient. The detection wavelength of the eluent drug was 283 nm.
Preparation of formic acid pH 3.2
In 100 ml volumetric flask formic acid (100 µl**) was taken and filled up to 100 ml using triple distilled water. The pH of this solution was adjusted to 3.2 using triethyl amine. 0.45 µm syringe filter was used to filter the solution and sonicated to remove the air bubbles.
Preparation of mobile phase
The mobile phase was prepared by mixing 90 parts of ACN and 10 parts of formic acid with a pH of 3.2. Using 0.45 µm syringe filter, mobile phase was filtered and was ultrasonicated to degas the mobile phase.
Preparation of standard stock solution
Accurately weighed TBZ (10 mg) was dissolved in the mobile phase in a 10 ml volumetric flask and filled with the mobile phase. It gave a stock solution of 1000 µg/ml. Serial dilutions were performed by taking 1 ml of the above solution and making it up to 10 ml resulting in a solution of 100 µg/ml, which on further dilution yield a solution of 10 µg/ml. From the prepared stock solution, serial dilutions were performed to get final concentrations of 2, 4, 6, and 8 µg/ml [11].
Method validation
The developed method was validated as per the ICH Q2 (R1) for linearity, accuracy, precision, robustness, and specificity [12].
System suitability
To determine the system suitability, peak purity index, tailing factor, and Height Equivalent to Theoretical Plate (HETP) [13] were calculated by injecting blank, followed by six replicates of system suitability sample i. e. 10µg/ml TBZ onto the HPLC system [14].
Preparation of quality control standards
Lower Quantified Concentration (LQC), Medium Quantified Concentration (MQC), and Higher Quantified Concentration (HQC) of the calibration curve was resulted on three different level of quality standard [15]. Consequently 6, 4.8 and 7.2 µg/ml was considered for MQC, LQC and HQC, respectively as 6 µg/ml was the centre value of calibration curve.
Linearity and range
The range of an analytical method is the gap between the sample lowest and the highest concentrations of sample for which the analytical procedure has a satisfactory level of precision. Linearity was evaluated by analyzing a series of various concentrations of TBZ. Five concentrations (2, 4, 6, 8, 10 µg/ml) of TBZ were injected six times each, and the regression equation was noted.
Accuracy
The quality and applicability of the developed method were checked by performing the recovery analysis of TBZ at three level i. e., LQC, MQC and HQC of the medium concentration which was 6µg/ml. Standard solutions (LQC, MQC and HQC) were injected six times, and the response mean values were recorded [16]. The percentage recovery was calculated from the following formula [17].
Percentage recovery can be calculated as actual conc. Recovered divided by theoretical conc. and obtained value will be multiplied by 100.
Precision studies
Precision studies were performed in two parts: repeatability and intermediate precision. In repeatability, standard solutions were injected six times each on the same day under the same conditions (intra-day). For the intermediate precision, an inter-day study was carried out by injecting six times of standard solution for three consecutive days and for the inter-analyst study, three different analysts of the same laboratory injected six times of standard solution, which were prepared by other analysts by following the identical conditions of experiment. The mean of responses was noted, and the %RSD was calculated.
Robustness
Robustness of the proposed procedure is to estimate of its value to remain unaltered by modest but considered changes in chromatographic settings, which was investigated by testing the influence of small alterations in terms of variation in the mobile phase such as in pH (3.0±0.2), the ratio of mobile phase ACN: Formic acid (88:12, 90:10, and 92:08), and flow rate (1.0±0.2 ml/min). Medium concentration of 6 µg/ml was injected for six times and the effect on the recovery, peak area, and retention time was noted.
Estimation of LOD and LOQ
LOD and LOQ can be calculated by three methods, i. e., visual evaluation, S/N ratio approach and standard deviation of the response and slope. The LOD and the LOQ were determined by the standard deviation of the response and slope method using the following formula [18].
(1)
…… (2)
Where S is the slope of the calibration curve and sigma (σ) is the Standard Deviation (SD) of slope.
Application of HPLC method in solubility and drug loading estimation
Determination of drug solubility
For the development of SNEDDS formulation, estimation of TBZ solubility is required. The solubility of different components of SNEDDS, such as surfactant, oil, and co-surfactant, was checked by the HPLC method [19, 20]. The solubility studies of TBZ were carried out in oils (eucalyptus, olive, cotton seed, capmul MCM, peanut, paraffin, caproyl 90, isopropyl myristate and caproyl PGMC), surfactants (tween 20, tween 60, tween 80, span 80, labrafil M 1944 CS, labrasol, labrafac WL 1349, labrafac PG and peceol) and co-surfactants (transcutol P, PEG 400, lauroglycol 90, lauroglycol FCC, transcutol HP, plurol oleique and maisin CC). In 1 ml of co-surfctant, oil, surfactant sufficient amount of 10 mg of drug was which further undergoes vortexing (cyclo mixer REMI, India). The vials were sealed and left for 72 h, with intermittent shaking every hour for 8 h [7, 21]. For thr confirmation of removal of undissolved drug the sample were subjected to centrifugation (REMI CM-12 PLUS, India) at 10000g for 20 min. The supernatants were collected and diluted with methanol, ethanol, chloroform, and hexane to determine the drug quantity [22].
Determination of drug loading in SNEDDS
The SNEDDS were formulated by adding 12.5 mg TBZ in 1 ml mixture of selected surfactant, oil, and co-surfactant. These formulations were diluted with triple distilled water up to 500 ml on a magnetic stirrer at 700-800 rpm at room temperature. The HPLC method was used to evaluate drug loading in SNEDDS formulation. Using syringe filter formulation sample was filtered [13] and injected into the HPLC system to analyze the TBZ peaks. Percent drug loading was calculated using the following equation [23]:
…. (3)
RESULTS AND DISCUSSION
Formulation
Formulation was evaluated for globule size, PDI, zeta potential and were found to be 68.73±2.79 nm, 0.451±0.08 and-20.2±1.79 mV (fig. 2), respectively. Size of the formulation was showing nano-range, PDI was showing good uniformity and homogeneity between the particles, zeta potential was also showing stability of bilayer.
Selection of mobile phase for TBZ estimation
Several mobile phase compositions in different ratios and pH have been used. Firstly, using ACN: 5 mmol ammonium acetate [1] peaks appeared with splitting and noise (fig. 4A). Secondly, trial with ACN: 0.1% glacial acetic acid was used as a mobile phase for estimating TBZ, but shouldering was observed (fig. 4B). Thirdly, upon using ACN: 0.1% ortho-phosphoric acid as a mobile phase, there was no sharp peak; instead, two peaks with shouldering were observed (fig. 4C). The reported methods have RT between 6.5-10 min [1, 9], and 0.1% formic acid and ACN have RT 4.34±0.03 (fig. 4D). Finally, using ACN: 0.1% formic acid pH 3.2 of ratio 90:10 as mobile phase better results in terms of resolution, sharpness of peaks was observed. Hence, this mobile phase combination was selected for validation. When a blank of 5 mmol ammonium acetate and ACN was injected, there was no peak which interfered with the TBZ peak RT. In addition, the same was observed with 0.1% formic acid and ACN (fig. 3).
Fig. 2: Globule size, PDI (2A), Zeta potential (2B)
Fig. 3: Chromatogram of blank of ACN and formic acid
Fig. 4: Chromatogram of TBZ in ACN and 5 mmol ammonium acetate (A), Chromatogram of TBZ in ACN and 0.1% glacial acetic acid (B), Chromatogram of TBZ in ACN and 0.1% ortho-phosphoric acid (C), Optimized chromatogram of TBZ in ACN and 0.1% formic acid (90:10) (D)
Method validation
System suitability
TBZ dilution of 10 µg/ml was injected for system suitability and results were compared with standard and previously reported studies. Tailing factor was found 1.10±0.002 which is less than 2 [1, 9] ensure peak regularity. Theoretical plate was found 6848±43, which is more than the previously conducted studies for quantification of TBZ using HPLC [1, 9] ensure excellent peak efficiency (table 1).
Linearity
The potential of an analytical process to bring out results that are directly proportional to the concentration (quantity) of sample is known as linearity [24]. The linearity of different concentrations of 2, 4, 6, 8, and 10 µg/ml was found. A graph was plotted taking area of peak on y-axis and concentration (µg/ml) along the x-axis (fig. 5). 0.9992 was r2 value with the regression equation y = 21946x+3403.2.
Table 1: System suitability results for TBZ
| Parameters | Value | Limits |
| HETP | 22.01±0.37 | Depends upon the theoretical plate |
| Theoretical plate | 6848±43 | >2000 |
| Theoretical plate/meter | 45652±287 | >20000 |
| Tailing factor | 1.10±0.002 | <2 |
| Peak purity index | 0.999 | >0.5 |
*Data are expressed as mean±SD; n=6
Fig. 5: Calibration curve of TBZ
Accuracy
Accuracy of standard solution was executed by percentage recovery of standard solutions. Percentage recovery was found in between 85.83%-91.38%. The accuracy of a test relates to how closely the results match the true value [25]. The obtained results are depicted in table 2.
Precision
Precision studies have been performed to check whether the method is repeatable. The obtained results are presented in table 3. The observed % RSD for intraday (0.64-1.96%), interday (0.60-1.880%), and interanalyst (0.60-1.91%) which were less than 2% for all the samples, which prove this method was satisfactorily, repeatable and precised [16].
Robustness
Robustness study was done by changing the pH of the mobile phase (3.0, 3.2 and 3.4), flow rate (0.8, 1.0 and 1.2 ml/min) and the ratio of mobile phase ACN: 0.1% formic acid (88:12, 90:10 and 92:08), respectively. The result of %RSD was in between 1.24-1.67% which were less than 2% (table 4), which showed this method was unaffected by these changes and satisfactory robust. This is the method in which three factors are considered for robustness.
Table 2: Result of accuracy studies
| Levels | Concentration of standard solution (µg/ml) | Concentration of drug added (µg/ml) | Recovered concentration (µg/ml) | Recovery (%) | Mean recovery (%) |
| LQC | 4.8 | 6.0 | 4.3 | 89.58 | 88.93 |
| MQC | 6.0 | 6.0 | 5.15 | 85.83 | |
| HQC | 7.2 | 6.0 | 6.58 | 91.38 |
*Data are expressed as mean±SD; n=6
Table 3: Outcomes of TBZ precision experiment
| Parameters | Level | Concentration | Analytical responses (area), injections | Mean | SD | %RSD | |||||
| (µg/ml) | 1 | 2 | 3 | 4 | 5 | 6 | (*N=6) | ||||
| Repeatability (intraday precision) | |||||||||||
| LQC | 4.8 | 99103 | 98742 | 98195 | 99752 | 98042 | 98570 | 98734.00 | 627.51 | 0.64 | |
| MQC | 6.0 | 104088 | 103671 | 106085 | 101326 | 103843 | 101238 | 103375.17 | 1839.80 | 1.78 | |
| HQC | 7.2 | 148847 | 147940 | 145179 | 146371 | 153138 | 145941 | 147902.70 | 2895.31 | 1.96 | |
| Interday | |||||||||||
| Day 1 | LQC | 4.8 | 100800 | 99300 | 97149 | 101644 | 97810 | 98708 | 99235.17 | 1727.22 | 1.74 |
| MQC | 6.0 | 113618 | 114959 | 114233 | 110419 | 110570 | 111176 | 112495.83 | 2005.40 | 1.78 | |
| HQC | 7.2 | 160419 | 160818 | 159205 | 158758 | 159698 | 157338 | 159372.67 | 1251.83 | 0.79 | |
| Day 2 | LQC | 4.8 | 102340 | 103721 | 102991 | 103161 | 102146 | 102269 | 102771.33 | 621.51 | 0.60 |
| MQC | 6.0 | 107957 | 106914 | 106610 | 106254 | 105701 | 106287 | 106620.50 | 769.87 | 0.72 | |
| HQC | 7.2 | 155035 | 152976 | 153634 | 151066 | 151668 | 155023 | 153233.67 | 1662.72 | 1.09 | |
| Day 3 | LQC | 4.8 | 106031 | 104058 | 105570 | 105581 | 106324 | 105939 | 105583.83 | 800.29 | 0.76 |
| MQC | 6.0 | 137157 | 136692 | 137042 | 137505 | 138961 | 139253 | 137768.33 | 1072.92 | 0.78 | |
| HQC | 7.2 | 189687 | 190240 | 197962 | 196294 | 197082 | 196424 | 194614.83 | 3655.29 | 1.88 | |
| Inter analyst | |||||||||||
| Analyst 1 | LQC | 4.8 | 97511 | 99155 | 98424 | 99086 | 98382 | 98581 | 98523.16 | 595.58 | 0.60 |
| MQC | 6.0 | 111095 | 112099 | 116379 | 114497 | 111248 | 114692 | 113335.00 | 2161.41 | 1.91 | |
| HQC | 7.2 | 152384 | 156990 | 150695 | 153388 | 156093 | 153763 | 153885.50 | 2332.69 | 1.52 | |
| Analyst 2 | LQC | 4.8 | 140015 | 145172 | 141923 | 141502 | 142676 | 142410 | 142283.00 | 1697.07 | 1.19 |
| MQC | 6.0 | 120018 | 117776 | 117572 | 113830 | 118311 | 116454 | 117326.83 | 2071.83 | 1.76 | |
| HQC | 7.2 | 160327 | 157810 | 162809 | 160533 | 161919 | 158078 | 160246.00 | 2004.55 | 1.25 | |
| Analyst 3 | LQC | 4.8 | 120202 | 126452 | 122477 | 124958 | 124815 | 123884 | 123798.00 | 2195.78 | 1.77 |
| MQC | 6.0 | 158504 | 154018 | 156134 | 150555 | 152525 | 154409 | 154357.50 | 2767.10 | 1.79 | |
| HQC | 7.2 | 196724 | 199904 | 200742 | 197805 | 194714 | 200525 | 198402.30 | 2408.82 | 1.21 | |
*Data are expressed as mean±SD; n=6
Table 4: TBZ robustness results
| Various parameters | Value | Concentration (µg/ml) | Peak (mean±SD) (*N=6) |
Mean of peak area of three value (*N=3) | Retention time (in min) (mean±SD) (*N=6) |
Mean of retention times of three values (*N=3) | % Recovery (mean±SD) (*N=3) |
Mean of % recoveries of three values (*N=3) |
| pH | 3.0 | 6.0 | 112306.70±7105.37 | 118090.73 | 4.93±0.01 | 4.99 | 105.09±0.97 | 104.78 |
| 3.2 | 6.0 | 114787.50±3189.42 | SD=2152.71 | 5.05±0.77 | SD=0.06 | 103.35±1.02 | SD=1.30 | |
| 3.4 | 6.0 | 119041.00±3597.69 | %RSD=1.82 | 5.01±0.58 | %RSD=1.19 | 105.90±1.23 | %RSD=1.24 | |
| Flow rate | 0.8 | 6.0 | 137009.70±3287.00 | 136192.00 | 4.42±0.02 | 4.50 | 100.00±1.57 | 100.33 |
| 1.0 | 6.0 | 137768.30±2299.50 | SD=2107.68 | 4.50±0.01 | SD=0.09 | 102.00±1.22 | SD=1.52 | |
| 1.2 | 6.0 | 133798.00±2437.00 | %RSD=1.54 | 4.60±0.03 | %RSD=2.00 | 99.00±1.58 | %RSD=1.52 | |
| Mobile phase ratio (A: B) | 88:12 | 6.0 | 126103.00±3958.50 | 124069.30 | 4.82±0.06 | 4.94 | 93.00±1.16 | 91.33 |
| 90:10 | 6.0 | 124168.20±1437.50 | SD=2084.75 | 5.03±0.04 | SD=0.06 | 91.00±1.05 | SD=1.52 | |
| 92:08 | 6.0 | 121937.00±1571.00 | %RSD=1.68 | 4.44±0.09 | %RSD=1.12 | 90.00±1.13 | %RSD=1.67 |
*Data are expressed as mean±SD; n=6
Fig. 6: Solubility of TBZ in oils, surfactants and co-surfactants, *data are expressed as mean±SD; n=3
Estimation of LOD and LOQ
As per ICH guidelines, LOD and LOQ were calculated by the standard deviation of response and slope. The method has very low LOD and LOQ values i. e. 0.31 μg/ml and 0.96 μg/ml, respectively, indicating that the presented method for TBZ estimation has high sensitivity [23].
Application of HPLC method in estimation of drug solubility
Solubility of TBZ
The solubility study of TBZ was done in various oil, surfactants and co-surfactants. The solubility was found highest in Labrafac WL1349, Transcutol P, and Capryol PGMC in surfactant, co-surfactant, and oil respectively (fig. 6). This study helps to select key components for SNEDDS formulations.
Determination of drug loading
The drug loading was found to be 79.2±1.6% in SNEDDS.
CONCLUSION
The developed RP-HPLC method for determining TBZ was reliable, selective and simple, providing adequate precision and accuracy with a lower limit of quantification and detection. The validation studies reported that the developed method was rugged and robust. So this method can be used to estimate the presence of TBZ in various pharmaceutical formulations. Further, the developed method can be used to determine the solubility of TBZ in different oil, surfactant and co-surfactants.
ACKNOWLEDGEMENT
The authors are thankful to Synnat Pharma Pvt. Ltd., India, for providing a gift sample of Tetrabenazine and Gattefosse, India, for providing gift samples of emulsifiers. Authors are also thankful to Central Instrumentation facility of Lovely Professional University for providing analytical support.
FUNDING
The authors declare that this study received no financial support.
AUTHORS CONTRIBUTIONS
Conceptualization Shashi (S.), Narendra Kumar Pandey (N. K. P.),; review and editing, S., N. K. P., and Sachin Kumar Singh (S. K. S.),; resources, S., N. K. P., Bimlesh Kumar (B. K.), S. K. S.,; Design, S., N. K. P., Kalvatala Sudhakar (K. S.), Saurabh Singh (S. S.); data collection and/or Processing S., N. K. P., B. K., S. S., K. V.; Analysis and Interpretation, N. K. P., Dileep Singh Baghel (D. S. B.); writing original draft, S., D. S. B., N. K. P.; supervision, N. K. P., S. K. S., B. K.
CONFLICT OF INTERESTS
No conflict of interest was declared by the authors.
REFERENCES
Derangula VR, Pilli NR, Nadavala SK, Adireddy V, Inamadugu JK, Ponneri V. Liquid chromatography-tandem mass spectrometric assay for the determination of tetrabenazine and its active metabolites in human plasma: a pharmacokinetic study. Biomed Chromatogr. 2013;27(6):792-801. doi: 10.1002/bmc.2862, PMID 23339053.
Bourezg Z, Cartiser N, Ettouati L, Guillon J, Lacoudre A, Pinaud N. Structural elucidation of two photolytic degradation products of tetrabenazine. J Pharm Biomed Anal. 2014;91:138-43. doi: 10.1016/j.jpba.2013.12.032, PMID 24457996.
Hussar DA. New drugs: clevidipine butyrate, difluprednate, and tetrabenazine. J Am Pharm Assoc. 2008;48(6):815-21. doi: 10.1331/JAPhA.2008.08546, PMID 19019814.
Chen JJ, Ondo WG, Dashtipour K, Swope DM. Tetrabenazine for the treatment of hyperkinetic movement disorders: a review of the literature. Clin Ther. 2012;34(7):1487-504. doi: 10.1016/j.clinthera.2012.06.010, PMID 22749259.
Sharma S, Narang JK, Ali J, Baboota S. Synergistic antioxidant action of vitamin E and rutin SNEDDS in ameliorating oxidative stress in a Parkinson’s disease model. Nanotechnology. 2016;27(37):375101. doi: 10.1088/0957-4484/27/37/375101, PMID 27491690.
Mistry RB, Sheth NS. A review: self-emulsifying drug delivery system. Int J Pharm Pharm Sci. 2011;3:23-8. doi: 10.13040/ijpsr.0975-8232.4(12).4494-507.
Chen L, Lin X, Xu X, Chen Y, Li K, Fan X. Self-nano-emulsifying formulation of Sonchus oleraceus Linn for improved stability: implications for phenolics degradation under in vitro gastrointestinal digestion. J Funct Foods. 2019;53:28-35. doi: 10.1016/j.jff.2018.12.009.
Dash RN, Mohammed H, Humaira T, Reddy AV. Solid supersaturatable self-nanoemulsifying drug delivery systems for improved dissolution, absorption and pharmacodynamic effects of glipizide. J Drug Deliv Sci Technol. 2015;28:28-36. doi: 10.1016/j.jddst.2015.05.004.
Mehvar R, Jamali F, Watson MW, Skelton D. Direct injection high‐performance liquid chromatography of tetrabenazine and its metabolite in plasma of humans and rats. J Pharm Sci. 1986;75(10):1006-9. doi: 10.1002/jps.2600751021, PMID 3795018.
Ansari MJ, Alnakhli M, Al-Otaibi T, Al Meanazel OA, Anwer MK, Ahmed MM. Formulation and evaluation of self-nanoemulsifying drug delivery system of brigatinib: improvement of solubility, in vitro release, ex-vivo permeation and anticancer activity. J Drug Deliv Sci Technol. 2021;61:102204. doi: 10.1016/j.jddst.2020.102204.
Pandey NK, Singh SK, Ghosh D, Khursheed R, Kumar R, Kapoor B. Method development and validation for simultaneous estimation of glimepiride and simvastatin by using reversed phase high-performance liquid chromatography. Res J Pharm Technol. 2020;13(4):1655-9. doi: 10.5958/0974-360X.2020.00300.5.
Dagron S. Ethik Und R. Forsch Am Menschen, Die International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH), H and b; 2014. p. 541-5. doi: 10.1007/978-3-642-35099-3_86.
Khursheed R, Singh SK, Kapoor B, Gulati M, Wadhwa S, Gupta S. Development and validation of RP-HPLC method for simultaneous determination of curcumin and quercetin in extracts, marketed formulations, and self-nanoemulsifying drug delivery system. Re: GEN Open. 2021;1(1):43-52. doi: 10.1089/regen.2021.0021.
Choudhury H, Gorain B, Karmakar S, Pal TK. Development and validation of RP-HPLC method: scope of application in the determination of oil solubility of paclitaxel. J Chromatogr Sci. 2014;52(1):68-74. doi: 10.1093/chromsci/bms206, PMID 23293041.
Kumar R, Kumar R, Khursheed R, Awasthi A, Khurana N, Singh SK. Development and validation of RP-HPLC method for estimation of fisetin in rat plasma. S Afr J Bot. 2021;140:284-9. doi: 10.1016/j.sajb.2020.05.010.
Kumar R, Kumar R, Khursheed R, Awasthi A, Ramanunny AK, Kaur J. Validated reverse phase-high-performance liquid chromatography method for estimation of fisetin in self-nanoemulsifying drug delivery system. Assay Drug Dev Technol. 2020;18(6):274-81. doi: 10.1089/adt.2020.983, PMID 32608988.
Chaudhari VS, Borkar RM, Murty US, Banerjee S. Analytical method development and validation of reverse-phase high-performance liquid chromatography (RP-HPLC) method for simultaneous quantifications of quercetin and piperine in dual-drug loaded nanostructured lipid carriers. J Pharm Biomed Anal. 2020;186:113325. doi: 10.1016/j.jpba.2020.113325, PMID 32380356.
Santhosh G, Nagasowjanya G, Ajitha A, Uma Y, Rao M. HPLC method development and validation: an overview. Life Science Informatics. 2014;4:274-80.
Khan AA, Akhtar S, Yadav Y, Atiya A, Alelwani W, Bannunah AM. Lopinavir-loaded self-nanoemulsifying drug delivery system for enhanced solubility: development, characterisation and caco-2 cell uptake. Curr Drug Deliv. 2023;20(10):1474-86. doi: 10.2174/1567201819666220817111054, PMID 35980056.
Kumar R, Khursheed R, Kumar R, Awasthi A, Sharma N, Khurana S. Self-nanoemulsifying drug delivery system of fisetin: formulation, optimization, characterization and cytotoxicity assessment. J Drug Deliv Sci Technol. 2019;54:101252. doi: 10.1016/j.jddst.2019.101252.
Shehata EM, Elnaggar YS, Galal S, Abdallah OY. Self-emulsifying phospholipid pre-concentrates (SEPPs) for improved oral delivery of the anti-cancer genistein: development, appraisal and ex-vivo intestinal permeation. Int J Pharm. 2016;511(2):745-56. doi: 10.1016/j.ijpharm.2016.07.078, PMID 27492016.
Khursheed R, Singh SK, Wadhwa S, Gulati M, Awasthi A, Kumar R. Exploring role of probiotics and ganoderma lucidum extract powder as solid carriers to solidify liquid self-nanoemulsifying delivery systems loaded with curcumin. Carbohydr Polym. 2020;250:116996. doi: 10.1016/j.carbpol.2020.116996, PMID 33049905.
Park JH, Kim DS, Mustapha O, Yousaf AM, Kim JS, Kim DW. Comparison of a revaprazan-loaded solid dispersion, solid SNEDDS and inclusion compound: physicochemical characterisation and pharmacokinetics. Colloids Surf B Biointerfaces. 2018;162:420-6. doi: 10.1016/j.colsurfb.2017.12.017, PMID 29248606.
Lakshmana Rao A, Prasanthi T, Anusha EL. RP-HPLC method development and validation for simultaneous estimation of linagliptin and empagliflozin. IND DRU. 2019;56(5):68-71. doi: 10.53879/id.56.05.11150.
Soni LK, Narsinghani T, Jain M. Development and validation of rp-hplc method for simultaneous estimation of metformin hydrochloride and repaglinide in tablet dosage form. J Liq Chromatogr Relat Technol. 2012;35(3):385-92. doi: 10.1080/10826076.2011.601492.