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\begin{document}


\def\RunningAuthor{Birendra Shrivastava et al.}
\firstPage{6793}
\articleType{Original Article}
\receivedDate{24 Sep 2020}
\acceptedDate{04 Nov 2020}
\revisedDate{09 Oct 2020}
\journalVolume{2020, 11}
\journalIssue{4}
\journalDoi{ijrps.v11i4.3629}
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\def\authorCount{3}
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\def\journalTitle{International Journal of Research in Pharmaceutical Sciences}

\title{\textbf{Method Development and validating the Detection and Determination of }\textbf{Cinacalcet} \textbf{ in bulk and its formulation using RP-HPLC}}
\author{Birendra~Shrivastava\textsuperscript{*}\textsuperscript{1},  
            Sai~Rajesh~Kollapudi\textsuperscript{2}, 
            Dinakar~A\textsuperscript{3}~\\[5pt]{\textsuperscript{1}Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Jaipur National University, Jagatpura, Jaipur {\textendash} 302017, India}~\\{\textsuperscript{2}Department of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Jaipur National University, Jagatpura, Jaipur {\textendash} 302017, India}~\\{\textsuperscript{3}Department of Pharmaceutical Analysis, Sun Institute of Pharmaceutical Education and Research, Kakupalli, Nellore, Andhra Pradesh - 524346, India}}

\begin{abstract}
Cinacalcet (INN), a calcium mimetic drug that mimics the activity of calcium in the body. It expresses itself by activation of calcium-sensing receptor allosterically in different organs and tissues. The secretion of parathyroid hormone is regulated principally by calcium-sensing receptors that are present on the surface of the parathyroid gland. Cinacalcet is used in the treatment of hyperparathyroidism, which is the usual consequence of parathyroid cancers and CKF. There had been a rapid increase in the number of drugs that are adding to each class of drugs. These drugs are formulated into newer formulations either in a single or multi-drug dosage forms. These newer marketed formulations demand a new investigation for the estimation of the drug in the formulations. The existing analytical techniques for those drugs are available in the research literature, but not all the methods are stable and economical to use. The objective of this work was to develop an analytical RP-HPLC method for the estimation of cinacalcet in bulk and tablet formulation. The emphasis was given to the short time of analysis, and simplicity in the method. RP-HPLC analysis of the drug satisfies the peak integrity, suitability, recovery of the drug. LOQ and LOD of the drug were achieved with high sensitivity. The data shows the precision of the method and the accuracy of the method. Overall, the data suggest that the proposed analytical method can be used to analyse the drug in the formulation. This method can be recommended for the routine analysis of the drug in its dosage form. 
\end{abstract}\def\keywordstitle{Keywords}

\begin{keywords}Cinacalcet,\newline RP-HPLC,\newline Mobile phase,\newline Retention time,\newline ICH guidelines
\end{keywords}
\twocolumn[ \maketitle {\printKwdAbsBox}]
\makeatletter{\raggedright\textsuperscript{*}Corresponding Author\par Name:\ Birendra~Shrivastava~\\ Phone:\ ~\\  Email:\ director\_pharmacy@jnujaipur.ac.in
        \par}\vspace*{-11pt}\hrulefill\par{\fontsize{12}{14}\selectfont ISSN: 0975-7538}\par% 
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        \makeatother
        
    
\section{Introduction}
 Cinacalcet (INN), a calcium mimetic drug that mimics the activity of calcium in the body. It expresses itself by activation of calcium-sensing receptor allosterically in different organs and tissues \unskip~\citep{921463:20663515}. The secretion of parathyroid hormone is regulated principally by calcium-sensing receptors that are present on the surface of the parathyroid gland. The present drug lowers the parathyroid hormone levels by elevating the calcium-sensing receptors sensitivity. This elevation causes the activation of extracellular calcium which inhibits the PTH secretion \unskip~\citep{921463:20663532}. The lowering of the PTH is generally associated with the decrease of the serum calcium level. Cinacalcet is used in the treatment of hyperparathyroidism, which is the usual consequence of parathyroid cancers and CKF (Chronic Kidney Failure) \unskip~\citep{921463:20663514}, (Figure~\ref{f-2ea45ac256e4}). \textbf{\space }

There had been a rapid increase in the number of drugs that are adding to each class of drugs. These drugs are formulated into newer formulations either in a single or multi-drug dosage forms. These newer marketed formulations demand a new investigation for the estimation of the drug in the formulations. The existing analytical techniques for those drugs are available in the research literature, but not all the methods are stable and economical to use. Few other methods are time-consuming too. Numerous drugs were estimated using HPLC, LC-MS \unskip~\citep{921463:20663528,921463:20663512}. The objective of this work was to develop an analytical RP-HPLC method for the estimation of cinacalcet in bulk and tablet formulation.
    
\section{Materials and Methods}
\textbf{Chemicals used}

Potassium Dihydrogen Phosphate, Acetonirtile and Orthophosphoric acid were used for the above study. All the chemicals and reagents were purchased from S.D. fine chem which are of analytical grade.

\textbf{Instruments used}

\textbf{UV-Visible Spectrophotometer} \textit{\space }

Pharmaspec-1700 model of UV-VISIBLE Spectrophotometer manufactured by SHIMADZU was used for the study. Software used to analyse the peaks is U.V. Probe 2.0.

\textbf{HPLC} \textbf{\space }

\textbf{Model of HPLC}

LC-2010CHT manufactured by SHIMADZU attached with an autosampler. The detector used was a PDA SPD-M20A Prominence-Diode Array Detector and UV-Visible. The column used was a Phenomenex Kromasil column with 5\ensuremath{\mu } 100 RC18 (250 mm x 4.6 mm, i.e., 5 microns) measurements. Software used to analyse the peaks is LC-solution.

\textbf{Mobile Phase}

Acetonitrile and Methanol are taken in 60:40 v/v mixed and were adjusted using a pump which is operated by software. 

The degassing is done, and the solvents used were of HPLC grade. Different solvents were used to store solvent systems.


\bgroup
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\begin{figure}[!htbp]
\centering \makeatletter\IfFileExists{images/c6a1ce7d-edbf-4331-9119-f5c2a368b48b-upicture1.png}{\includegraphics{images/c6a1ce7d-edbf-4331-9119-f5c2a368b48b-upicture1.png}}{}
\makeatother 
\caption{\boldmath {Chemical structure of Cinacalcet}}
\label{f-2ea45ac256e4}
\end{figure}
\egroup

\bgroup
\fixFloatSize{images/af58a8f3-a8c4-4c9a-8ae2-2557f96c0dd9-upicture2.png}
\begin{figure}[!htbp]
\centering \makeatletter\IfFileExists{images/af58a8f3-a8c4-4c9a-8ae2-2557f96c0dd9-upicture2.png}{\includegraphics{images/af58a8f3-a8c4-4c9a-8ae2-2557f96c0dd9-upicture2.png}}{}
\makeatother 
\caption{\boldmath {Calibration curve of Cinacalcet}}
\label{f-937965da9ed7}
\end{figure}
\egroup
 \textbf{Preparation of Standard solution}

1mg of accurately weighed pure drug, Cinacalcet was dissolved in 5ml of the diluent solution and ultrasonicated for about 30mins. In another volumetric flask, 10mg of the impurity A-Cinacalcet was weighed and dissolved in 10ml of diluents. 0.5ml of this solution was pipetted out and labelled as a working solution. The final volumes were made with diluents and used for further analysis \unskip~\citep{921463:20663518}. 

\textbf{Preparation of sample solution}

An accurately weighed quantity of oral suspension powder equivalent to 10mg of the drug was dissolved in 60ml of methanol. This mixture was sonicated for 30min to ensure proper dissolution. This solution was filtered through a filter paper, and the residue was washed with methanol. The solution was diluted to the mark with methanol. 10ml of standard stock solution was transferred to a 100ml volumetric flask. The final volume was adjusted to 10 \ensuremath{\mu }g/ml with methanol and used for further study \unskip~\citep{921463:20663537,921463:20663513}. 

\textbf{The chromatographic conditions}

The flow rate was maintained at 1ml/min. The temperature was maintained at 30\ensuremath{^\circ}C. The injection volume and runtime were maintained at 10mL and 10min. The detection was done at 262nm.  


\bgroup
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\begin{figure*}[!htbp]
\centering \makeatletter\IfFileExists{images/0e88b12f-c24f-4c18-a188-1fa37fa04d46-upicture3.png}{\includegraphics{images/0e88b12f-c24f-4c18-a188-1fa37fa04d46-upicture3.png}}{}
\makeatother 
\caption{\boldmath {LOD\& LOQ Chromatogram of Cinacalcet}}
\label{f-68cfc213c330}
\end{figure*}
\egroup
\textbf{Determination of } \textbf{\ensuremath{\lambdabar}max}

The standard solution made of pure Cinacalcet was injected in the HPLC, and U.V. spectrum between of 200 to 400 nm was determined with the help of software, L.C. solution \unskip~\citep{921463:20663522}. 

\textbf{Method Validation}

\textbf{Linearity and range}

The plotting of the calibration curve was performed with concentration ranges of the cinacalcet solution of 50\% 75\% 100\% 125\% 150\%. These concentrations were made using standard cinacalcet drug. These solutions were vialed and auto sampled. 20\ensuremath{\mu }l samples of the solutions were injected into the autosampler by maintaining the chromatographic conditions. The calibration curves were obtained by plotting the peak area vs the concentration of the drug. The regression constant from the slope was determined \unskip~\citep{921463:20663530,921463:20663516}.

\textbf{Accuracy (\% Recovery) }

The drug recovery was calculated to determine the accuracy and recovery by adopting the standard addition method. Samples of known concentration of the drug were added to the previously analysed samples of the powder. The quantity of the cinacalcet was analysed by considering the values of the regression equation from the calibration curve. The experiments were repeated for 6 times. 


\bgroup
\fixFloatSize{images/2d605410-6cf2-44f4-94df-12f1eb95780a-upicture4.png}
\begin{figure}[!htbp]
\centering \makeatletter\IfFileExists{images/2d605410-6cf2-44f4-94df-12f1eb95780a-upicture4.png}{\includegraphics{images/2d605410-6cf2-44f4-94df-12f1eb95780a-upicture4.png}}{}
\makeatother 
\caption{\boldmath {System suitability chromatogram of Cinacalcet}}
\label{f-681943bc3406}
\end{figure}
\egroup
\textbf{Precision}


\begin{table}[!htbp]
\caption{\boldmath {Linearity Results} }
\label{tw-09547120d8fb}
\def\arraystretch{1.1}
\ignorespaces 
\centering 
\begin{tabulary}{\linewidth}{LLL}
\tbltoprule \rowcolor{kwdboxcolor}Sl \mbox{}\protect\newline  No & Concentration (\ensuremath{\mu}g/ml) & Peak Area\\
\tblmidrule 
1 &
  18.75 &
  297899\\
2 &
  37.5 &
  647222\\
3 &
  56.25 &
  958626\\
4 &
  75 &
  1223095\\
5 &
  93.75 &
  1553219\\
\tblbottomrule 
\end{tabulary}\par 
\end{table}
\textbf{Method precision (\% Repeatability) }

The sample injection was done 6 times repeatedly into the instrument. The results were reported in terms of \% of the variance which should not exceed 2\%. \textbf{\space }

\textbf{Day precision }


\begin{table*}[!htbp]
\caption{\boldmath {Accuracy Results} }
\label{tw-38467388a1c5}
\def\arraystretch{1.1}
\ignorespaces 
\centering 
\begin{tabulary}{\linewidth}{LLLLLLL}
\tbltoprule \rowcolor{kwdboxcolor}Level of spike & Weight of sample  & Area of Sample & Quantity added in \ensuremath{\mu}g/ml  & Quantity found in \ensuremath{\mu}g/ml  & Recovery percentage \% & Mean percentage \%\\
\tblmidrule 
50\% &
  37.50 &
  608783 &
  49.550 &
  49.71 &
  100 &
  \multicolumn{1}{p{\dimexpr(\mcWidth{7})}}{\multirow{6}{\linewidth}{100}}\\
50\% &
  37.50 &
  610503 &
  49.550 &
  49.68 &
  100 &
  \\
50\% &
  37.50 &
  607132 &
  49.550 &
  49.70 &
  100 &
  \\
50\% &
  37.50 &
  607132 &
  49.550 &
  49.65 &
  100 &
  \\
50\% &
  37.50 &
  601708 &
  49.550 &
  49.77 &
  100 &
  \\
50\% &
  37.50 &
  607089 &
  49.550 &
  49.71 &
  100 &
  \\
100\% &
  75.00 &
  1208783 &
  99.100 &
  99.55 &
  100 &
  \multicolumn{1}{p{\dimexpr(\mcWidth{7})}}{\multirow{3}{\linewidth}{100}}\\
100\% &
  75.00 &
  1210503 &
  99.100 &
  99.58 &
  100 &
  \\
100\% &
  75.00 &
  1204001 &
  99.100 &
  99.48 &
  100 &
  \\
150\% &
  112.50 &
  1835361 &
  148.650 &
  149.41 &
  101 &
  \multicolumn{1}{p{\dimexpr(\mcWidth{7})}}{\multirow{6}{\linewidth}{100}}\\
150\% &
  112.50 &
  1837303 &
  148.650 &
  149.34 &
  100 &
  \\
150\% &
  112.50 &
  1831982 &
  148.650 &
  149.39 &
  101 &
  \\
150\% &
  112.50 &
  1835361 &
  148.650 &
  149.45 &
  101 &
  \\
150\% &
  112.50 &
  1837303 &
  148.650 &
  149.29 &
  100 &
  \\
150\% &
  112.50 &
  1831982 &
  148.650 &
  149.34 &
  100 &
  \\
\tblbottomrule 
\end{tabulary}\par 
\end{table*}

\begin{table*}[!htbp]
\caption{\boldmath {Repeatability Results} }
\label{tw-44e63397c615}
\def\arraystretch{1.1}
\ignorespaces 
\centering 
\begin{tabulary}{\linewidth}{p{\dimexpr.1047\linewidth-2\tabcolsep}p{\dimexpr.20900000000000002\linewidth-2\tabcolsep}p{\dimexpr.3259\linewidth-2\tabcolsep}p{\dimexpr.1891\linewidth-2\tabcolsep}p{\dimexpr.1713\linewidth-2\tabcolsep}}
\tbltoprule \rowcolor{kwdboxcolor}Sl \mbox{}\protect\newline No & Sample Name & Peak Name & R.T. & Area\\
\tblmidrule 
1 &
  Precision 1 &
  Cinacalcet Hydrochloride &
  3.725 &
  1208703\\
2 &
  Precision 2 &
  Cinacalcet Hydrochloride &
  3.703 &
  1204101\\
3 &
  Precision 3 &
  Cinacalcet Hydrochloride &
  3.746 &
  1207232\\
4 &
  Precision 4 &
  Cinacalcet Hydrochloride &
  3.706 &
  1206332\\
5 &
  Precision 5 &
  Cinacalcet Hydrochloride &
  3.712 &
  1201808\\
6 &
  Precision 6 &
  Cinacalcet Hydrochloride &
  3.711 &
  1217189\\
\tblbottomrule 
\end{tabulary}\par 
\end{table*}

\begin{table*}[!htbp]
\caption{\boldmath {Intermediate Precision Results} }
\label{tw-b02dbdb16a2a}
\def\arraystretch{1.1}
\ignorespaces 
\centering 
\begin{tabulary}{\linewidth}{p{\dimexpr.0975\linewidth-2\tabcolsep}p{\dimexpr.23409999999999997\linewidth-2\tabcolsep}p{\dimexpr.34400000000000006\linewidth-2\tabcolsep}p{\dimexpr.1586\linewidth-2\tabcolsep}p{\dimexpr.1658\linewidth-2\tabcolsep}}
\tbltoprule \rowcolor{kwdboxcolor}Sl \mbox{}\protect\newline No & Sample Name & Peak Name & R.T. & Area\\
\tblmidrule 
1 &
  INT-Precision 1 &
  Cinacalcet Hydrochloride &
  3.739 &
  1208783\\
2 &
  INT-Precision 2 &
  Cinacalcet Hydrochloride &
  3.717 &
  1210503\\
3 &
  INT-Precision 3 &
  Cinacalcet Hydrochloride &
  3.742 &
  1204001\\
4 &
  INT-Precision 4 &
  Cinacalcet Hydrochloride &
  3.701 &
  1207132\\
5 &
  INT-Precision 5 &
  Cinacalcet Hydrochloride &
  3.715 &
  1201708\\
6 &
  INT-Precision 6 &
  Cinacalcet Hydrochloride &
  3.701 &
  1207089\\
\tblbottomrule 
\end{tabulary}\par 
\end{table*}
The intra and inter-day precision were evaluated in 3 different concentrations of the drug. The intra-day precision was calculated by analysing samples thrice in one day, and inter-day was calculated by analysing samples thrice over three days. The results were reported as \% variance. \textbf{\space }


\begin{table*}[!htbp]
\caption{\boldmath {System suitability results} }
\label{tw-7492a025e78c}
\def\arraystretch{1.1}
\ignorespaces 
\centering 
\begin{tabulary}{\linewidth}{p{\dimexpr.5854\linewidth-2\tabcolsep}p{\dimexpr.4146\linewidth-2\tabcolsep}}
\tbltoprule \rowcolor{kwdboxcolor}Parameter  & Value \\
\tblmidrule 
Rt-(Minutes) &
  3.7\\
Resolution -Rs &
  3.4\\
Theoretical plates-TP &
  3265\\
Tailing factor-Tf &
  1.0\\
Asymmetric factor-Af &
  0.67\\
Capacity factor-K' &
  6.5\\
\tblbottomrule 
\end{tabulary}\par 
\end{table*}
\textbf{Robustness}

Robustness was estimated by making minor changes in the mobile phase ratios and injection volumes. The column temperature and the flow rates were also changed by a small extent to find the robustness. It was analysed at three concentrations, and the results were expressed in \% variance. \textbf{\space }

\textbf{LOD \& LOQ}

The limits of detection (L.O.D) and the limits of quantification (L.O.Q) of this method were estimated visually based on trial and error.


\begin{table*}[!htbp]
\caption{\boldmath {Solution stability results} }
\label{tw-c00aaf01ca78}
\def\arraystretch{1.1}
\ignorespaces 
\centering 
\begin{tabulary}{\linewidth}{p{\dimexpr.06330000000000001\linewidth-2\tabcolsep}p{\dimexpr.2522\linewidth-2\tabcolsep}p{\dimexpr.2809\linewidth-2\tabcolsep}p{\dimexpr.2036\linewidth-2\tabcolsep}p{\dimexpr.20\linewidth-2\tabcolsep}}
\tbltoprule \rowcolor{kwdboxcolor}Sl \mbox{}\protect\newline No & Sample Name & Peak Name & R.T. & Area\\
\tblmidrule 
1 &
  Acid &
  Cinacalcet Hydrochloride &
  3.705 &
  3183248\\
2 &
  Base &
  Cinacalcet Hydrochloride &
  3.688 &
  3924866\\
3 &
  Peroxide &
  Cinacalcet Hydrochloride &
  3.731 &
  4526402\\
4 &
  Heat &
  Cinacalcet Hydrochloride &
  3.703 &
  4835827\\
5 &
  Sunlight &
  Cinacalcet Hydrochloride &
  3.716 &
  4926787\\
\tblbottomrule 
\end{tabulary}\par 
\end{table*}
\textbf{Selectivity and Specificity}

The specificity of this developed method was analysed by a resolution factor which corresponds to the drug peak within the nearest resolving peaks and also to all the other available peaks. The data of peak purity confirms the selectivity with the help of a PDA detector. To assess the method selectivity, a placebo was prepared with oral suspension powder without cinacalcet and the same is compared with the prepared cinacalcet standard to investigate the selectivity of the method. The chromatograms of standard and the placebo were prepared. The comparisons were made between the retention time Rt, Purity and Resolution factor. 

\textbf{System suitability}

Resolution (Rs), the capacity factor (K'), asymmetry factor (As), retention time-(RT), theoretical plates (Tp), and tailing factor-(Tf) was reported in the E.P. by using L.C. software. HPLC was calibrated with the initial mobile phase with 6 injections of the common standard solution. To establish the suitability of the system to the analysis, 6 samples were prepared using the standard solutions and were analysed \unskip~\citep{921463:20664692,921463:20663525}.\textbf{\space }

\textbf{Solution stability}

The stability of the solution of the drug was assayed in the method by storing the solution in a tightly sealed container for 24 hrs. Samples from this stock solution were analysed at regular intervals of 6, 18 and 24hrs. The results obtained from this test were compared with the freshly prepared solutions. 
    
\section{Results and Discussion}
All the results of the studies in the RP-HPLC of the drug were documented for the Accuracy, Precision, Linearity, LOD and LOQ. 

\textbf{Linearity and range}

The linearity of the analytical method was investigated at 7 different concentrations using methanol as a diluent, and the prepared concentrations ranged from 50-150\%. The results showed a perfect relationship between peak area vs concentration of the analysed sample. The calibration curve was determined, and the AUC was estimated using the detector. The liner graph was plotted with \textit{an r}2 value of 0.9972, which gave the best linearity. The results were demonstrated in Table~\ref{tw-09547120d8fb}.


\begin{table*}[!htbp]
\caption{\boldmath {Robustness Results} }
\label{tw-8e6b3ea59e31}
\def\arraystretch{1.1}
\ignorespaces 
\centering 
\begin{tabulary}{\linewidth}{p{\dimexpr.0873\linewidth-2\tabcolsep}p{\dimexpr.1477\linewidth-2\tabcolsep}p{\dimexpr.2287\linewidth-2\tabcolsep}p{\dimexpr.12590000000000002\linewidth-2\tabcolsep}p{\dimexpr.11809999999999999\linewidth-2\tabcolsep}p{\dimexpr.1413\linewidth-2\tabcolsep}p{\dimexpr.151\linewidth-2\tabcolsep}}
\tbltoprule \rowcolor{kwdboxcolor}Sl No & Sample Name & Peak Name & R.T. & Area & USP Trailing & USP Plate Count\\
\tblmidrule 
1 &
  Flow 1 &
  Cinacalcet Hydrochloride &
  4.410 &
  6108891 &
  1.56 &
  3357\\
2 &
  Flow 2 &
  Cinacalcet Hydrochloride &
  3.222 &
  4487968 &
  1.68 &
  3032\\
3 &
  Temp 1 &
  Cinacalcet Hydrochloride &
  3.690 &
  5179221 &
  1.57 &
  3994\\
4 &
  Temp 2 &
  Cinacalcet Hydrochloride &
  3.702 &
  5177191 &
  1.50 &
  3195\\
\tblbottomrule 
\end{tabulary}\par 
\end{table*}
\textbf{Accuracy (\% Recovery)}

The drug was recovered at many concentrations which indicate the accuracy of this method. The pre measured quantity of the drug is taken and mixed with the already analysed solution. The same process was repeated over 3 repeated days and to determine the precision in the inter-day validation. The resultant \% of the variance of this method was estimated to be {\textless}2\% along with a good percentage of the recovery. The results were tabulated in Table~\ref{tw-38467388a1c5}  and Figure~\ref{f-937965da9ed7}.

\textbf{Precision (\% Repeatability)}

The precision of the analysis was determined by repeated injection of the drug solution for 6 times. The results were given in Table~\ref{tw-44e63397c615}  and were expressed as \% variance that did not exceed 2\% \unskip~\citep{921463:20663520,921463:20663523}.

\textbf{Inter-day and Intra-day precision}

The precision of the inter-day and intra-day variations were analysed at different concentrations were documented in Table~\ref{tw-b02dbdb16a2a}. The variance was not significant, which supports there are an intra and inter-day precision of the proposed method of analysis.

\textbf{Limit of detection and quantitation}

The LOD and LOQ were determined for the drug. The least concentration of the drug and LOQ were  determined by measuring accuracy and precision (Figure~\ref{f-68cfc213c330}).

\textbf{System suitability} \textbf{\space }

The measurement of the suitability of the system is an embedded module of the HPLC analytical method-development to determine the system was suitable for this analysis. The results were tabulated in Table~\ref{tw-7492a025e78c}. The results were in acceptance of the CDER guidelines (Figure~\ref{f-681943bc3406}).

\textbf{Solution stability}

The percentage of the variance of the drug solution was found to be under limits when tested for the stability study. The data obtained in the study were tabulated in Table~\ref{tw-c00aaf01ca78}. This analysis showed that the drug solutions were stable, and the results showed that the sample responded well, and the data was within limits of less than 2\%. 

\textbf{Robustness}

The robustness of the experiment was determined by changing a few parameters like mobile phase, Flow rate, Column and Injection volume of the sample. The method was performed at various concentrations of 0.6,0.8 and 1.0\ensuremath{\mu }g/ml. The values were tabulated in Table~\ref{tw-8e6b3ea59e31}.
    
\section{Conclusions}
The drug, cinacalcet, was estimated using the analytical method that is proposed in the study. The method was studied for its simplicity, accuracy, precision and specificity. The proposed analytical method is suitable for the routine analysis of the drug in the dosage form. The simplicity of the analysis was emphasised due to the lack of sophisticated instruments like LC-MS. The emphasis was given to the short time of analysis, and simplicity in the method. RP-HPLC analysis of the drug satisfies the peak integrity, suitability, recovery of the drug. LOQ and LOD of the drug were achieved with high sensitivity. The data shows the precision of the method and the accuracy of the method. Overall, the data suggest that the proposed analytical method can be used to analyse the drug in the formulation. This method can be recommended for the routine analysis of the drug in its dosage form.
\section*{Acknowledgement}The authors are thankful to all who have extended their constant support for the completion of the work.\textbf{\space }

\textbf{Funding Support}

The authors declare that they have no funding support for this study.

\textbf{Conflict of Interest}

The authors declare that they have no conflict of interest for this study.
    

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