Targeted Colonic Delivery of Duranta erecta Extract via a Mucoadhesive Herbal Tablet: A Novel Approach for Localized Anthelmintic Therapy

Helminthic infections are a major public health concern, especially in tropical and sub-tropical regions. These infections are caused by parasitic worms such as roundworms, tapeworms, and flukes that inhabit the gastrointestinal tract, often leading to severe nutritional deficiencies, anaemia, impaired growth, and cognitive deficits, especially in children.[1] Despite the availability of synthetic anthelmintic drugs, issues such as drug resistance, poor patient compliance, systemic toxicity, and recurrence necessitate the exploration of novel therapeutic strategies. Parasitic worms, or helminths, lead to long-lasting and sometimes fatal illnesses that significantly affect global socio-economic conditions.[2] Worldwide, around 14 million people suffer from these worm-related infections, which are classified as neglected tropical diseases (NTDs).[3] Herbal medicine has gained significant attention in recent decades for its efficacy, safety, and minimal side effects.[4] Duranta erecta, a medicinal plant known for its antimicrobial, antioxidant, and anthelmintic activities, presents promising potential as a natural therapeutic agent.[5] Its phytoconstituents, including alkaloids, flavonoids, and saponins, contribute to its antiparasitic effects. However, to maximize its therapeutic efficacy, it is crucial to deliver the active constituents specifically to the site of infection, i.e., the colon, where the parasitic worms primarily reside. [6]Colon-targeted drug delivery systems (CDDS) offer a strategic approach to deliver drugs directly to the large intestine, bypassing the upper gastrointestinal tract.[7] Among the various techniques, mucoadhesive drug delivery has emerged as a superior strategy owing to its ability to prolong the residence time at the target site, enhancing drug absorption and bioavailability.[8] By incorporating mucoadhesive polymers in the tablet formulation, the dosage form can adhere to the colonic mucosa and ensure sustained drug release at the site of action.[9],This research aims to develop and evaluate colon-targeted mucoadhesive herbal tablets containing Duranta erecta for anthelmintic therapy. Furthermore, the study introduces an innovative approach to quantify mucoadhesion retention time using novel instrumentation. This device will help in real-time evaluation of mucoadhesive strength and retention under simulated physiological conditions, offering valuable insights into the performance of the formulation. Rationale behind colon targeted tablet formulation development is site specific delivery of natural origin anti-helminthic drug.  The increasing resistance of helminths to conventional anthelmintic agents like albendazole and mebendazole demands the exploration of alternative therapies that are both effective and sustainable.  Herbal medicines offer a safer therapeutic profile with lesser side effects. Duranta erecta has shown promising anthelmintic activity in preliminary studies but lacks proper formulation for targeted delivery.[10]Additionally, colon-specific mucoadhesive systems help protect herbal bioactive compounds that are otherwise susceptible to degradation in the acidic and enzymatic conditions of the upper gastrointestinal tract, thereby preserving their pharmacological activity until they reach the colon.[11] Many phytochemicals such as flavonoids, alkaloids, and tannins show poor stability in gastric pH, so preventing their early degradation significantly enhances their therapeutic potential [12,13]. Targeted drug delivery also provides the advantage of dose reduction because the active constituents are released precisely at the site where helminths reside, minimizing systemic side effects.[14] The use of mucoadhesive polymers ensures prolonged retention of the formulation on the colonic mucosa, improving therapeutic performance through extended residence time.[15] Furthermore, the incorporation of advanced instrumentation for mucoadhesion testing allows more accurate and reproducible assessment of adhesion behaviour under physiologically relevant conditions, supporting better formulation optimization and improving the chances of successful clinical application. Colon-targeted systems help bypass first-pass metabolism, particularly beneficial for herbal compounds that undergo extensive hepatic biotransformation when absorbed from the upper GIT. The colonic environment, characterized by a neutral pH and dense microbial flora, also supports the enzymatic degradation of specific polysaccharide-based coatings, allowing precisely timed drug release through microbiota-triggered mechanisms.[7,16] Novel instrumentation for measuring mucoadhesion strength under dynamic flow conditions provides deeper insight into the real-time interactive forces between polymeric tablets and mucosal surfaces, thus offering more reliable prediction of in vivo performance. The integration of such advanced evaluation tools further accelerates formulation optimization and enhances the potential for clinical translation of mucoadhesive colon-targeted herbal tablets.
MATERIAL & METHOD: 
The leaves of Duranta erecta are collected from Bramhanal, Sangli, Maharashtra, India.  Authenticated by Dr. Patangrao Kadam Mahavidyalay, Sangli. Methanol, carbopol 934, sodium alginate, ethyl cellulose, sodium saccharin, magnesium stearate purchased from Loba chemicals, Mumbai. 
 
Fig no. 1.  Plant of Duranta erecta
The selection of crude Duranta erecta as the drug candidate for this formulation was inspired by its promising results in the research study.[10] This study investigated the methanolic extract of Duranta erecta leaves for its anthelmintic potential using Eisenia fetida (Indian earthworm) as the model organism. The leaves are separated from stems and dried in shade for 8 to 10 days. The dried leaves are powdered & extracted by cold maceration process. The extract was evaporated on hot plate (40°C) to dry the extract and tested for phytochemical constituents. Considering its efficacy, natural origin, and the presence of multiple pharmacologically active compounds, Duranta erecta methanolic extract was selected as the ideal candidate for the development of a mucoadhesive anthelmintic tablet. This selection supports the pursuit of a more effective, herbal-based alternative with fewer side effects and better patient compliance.
PREFORMULATION STUDIES:
Determination of minimum concentration of Duranta erecta having anthelmintic activity: The concentration of methanolic extract of Duranta erecta leaves were prepared in order to make 2mg/ml, 5mg/ml, 10mg/ml, 20mg/ml, 50mg/ml, 100mg/ml and tested its anthelmintic potential using Eisenia fetida (Indian earthworm).
Brine shrimp lethality assay (BSLA):[17] The brine shrimp lethality assay was used as a preliminary toxicity screening tool to identify a safe concentration range & used to decide the maximum safe concentration of dried extract. The dose of extract of Duranta erecta was selected well below the LC?? value to avoid cytotoxic effects. Three concentrations of extract (50mg/ml, 100mg/ml & 150mg/ml) were prepared. Three replicates were used for each concentration, while control vials contained distilled water. Artificial sea water was prepared by dissolving crude sea salt (25 g/L) and Brewer’s yeast (6 mg/L) in distilled water and filtering the solution. Brine shrimp eggs (40 mg) were hatched in 2 L of sea water for 48 h in a darkened chamber, and the phototropic nauplii were collected from the illuminated side. The bioassay was conducted according to Meyer et al. (1982) by transferring 10 nauplii into each vial containing 4.5 mL of sea water, followed by addition of 0.5 mL of the test or control solution. After 24 h of incubation, the surviving nauplii were counted under magnification, and percentage mortality was calculated.  
Brine shrimp lethality assay = % mortality = (Total naupii – Alive naupii) / Total naupii x 100
LC50 = C1 + ((50-M1)(C2-C1))/((M2-M1))
Where:
    C? = lower concentration
    C? = higher concentration
    M?, M? = corresponding mortalities
Selection of excipients: Excipients were selected based on thorough literature survey on herbal excipients, mucoadhesive, colon retentive herbal formulations research & review etc.[18] Concentrations of these excipients were selected trial & error, practical based evidences. Heckel plot analysis was employed to evaluate the influence of binder concentration on the compression behaviour of the formulated powder blends. Tablets containing varying levels of binder were compressed at different applied pressures, and the relative density of each compact was calculated using the ratio of tablet density to true density of the powder blend. The Heckel equation was applied by plotting ln[1/(1 − D)] against the corresponding compression pressure, and the linear region of the plot was used to determine the Heckel slope and mean yield pressure (Py). Changes in Py with increasing binder concentration were used as an indicator of plastic deformation behaviour and particle bonding efficiency. An optimal binder concentration was selected based on improved plastic deformation, reflected by a lower Py value and enhanced densification without compromising tablet integrity. This approach enabled rational selection of binder level by correlating compression mechanics with formulation composition.[19] 
Analytical method development (UV spectrophotometer): Double Distilled Water (DDW) is selected for development of calibration curve. Duranta erecta methanolic extract has been shown maximum absorption at 283nm. 100mg dried extract of Duranta erecta dissolved in small amount methanol then volume adjusted up to 100 ml with DDW (1mg/ml) (stock solution). Further diluted in order to get 10, 20, 40, 60 & 80 µg/ml. Measured the absorbance of each standard solution at the wavelength 283nm. Constructed a calibration curve with concentration on the X-axis and absorbance on the Y- axis. The relationship between concentration and absorbance should be linear.
Compatibility studies: In order to evaluate the integrity and compatibility of the drug in the formulation IR spectra of the drug – selected polymer and polymer-polymer mixture were obtained by FTIR spectrophotometer.
FORMULATION DEVELOPMENT: 
Selection of critical formulation variables & employment of DoE: 22 full-factorial design approach was employed to study the influence of mucoadhesive polymers on the performance of the tablet. A 2² full factorial design was selected to systematically evaluate the individual and interactive effects of two critical formulation variables concentration of Carbopol 934P (%w/v) & concentration of Sodium alginate (%w/v) on the performance of the formulation using a minimal number of experimental runs. The study focused on evaluating the effect of these critical formulation variables on key parameter such as mucoadhesion retention time.
 
    Table no 1 Composition of mucoadhesive tablet formulation trial batches
 
Formulation    Role of excipient    F1    F2    F3    F4
Carbopol 934    Mucoadhesive polymer    3%    1%    3%    1%
Sodium Alginate    Mucoadhesive polymer    24%    24%    12%    12%
Dried extract    Crude drug extract    1%    1%    1%    1%
Sodium saccharine    Sweetener    0.7%    0.7%    0.7%    0.7%
Lactose    Filler/diluent    64.3%    67.3%    76.3%    78.3%
Talc    Glidant    1%    1%    1%    1%
Magnesium stearate    Lubricant    2%    2%    2%    2%
PVP K30    Binder    4%    4%    4%    4%
Ethanol    Vehicle    q.s    q.s    q.s    q.s
 
Granulation: Wet granulation methods for formulation of mucoadhesive herbal tablet was selected. Duranta erecta was blended with the primary polymer (Carbopol 934), secondary polymer (sodium alginate), and lactose for 15 minutes. The resulting powder mixture was then granulated using an appropriate amount of ethanol as the binding solvent until a wet mass was achieved, as confirmed by a positive ball test. This cohesive mass was passed through a 1.25 mm sieve and dried at 40°C for one hour. The dried granules were then sieved through a 0.630 mm mesh. Following this, magnesium stearate and talc were added to the granules and mixed for 5 minutes. Finally, the prepared blend was compressed into tablets using the same compression machine for further evaluation.
Evaluation of prepared granules: The prepared granules were evaluated for Granule volume (Vg), Bulk volume (Vb), Volume of void (V), True density (ρ), Bulk density (ρb), Tapped density (ρt), Compressibility (Carr's) index , Angle of repose, Hausner's ratio, Size distribution by sieve analysis.
Tablet compression: The tablet was compressed by using the single punch press machine (SSP 25.). Magnesium stearate and the talc was added to improve flow property of granules, the granules are filled in to die cavity at proper dosing by the hopper and excess powder was removed and by the mechanical force of upper and lower punch the granules was compressed in tablets.
Enteric coating:[9] The dip coating method were preferred for enteric coating.  10% concentration of Polymer Eudragit L100 in ethanol & 10% PEG in ethanol were prepared separately. Both solution mixed both solutions. Dry dust free each tablet were immersed completely in the solution for 5 seconds (dwell time) & withdrawn at a controlled steady speeda and allowed excess solution to drain, rotate to prevent edge or tear build up. 
Evaluation tests of tablets[20]: Prepared tablets were evaluated for Appearance, Size and thickness, Hardness, Friability, Weight variation test, Disintegration test.
Mucoadhesion force determination: The mucoadhesive property of the prepared tablets were determined using in-house build modified two pan balance novel mucoadhesion measurement device. Freshly excised goat intestinal mucosa obtained from a local slaughter house was fixed on the lower platform with the mucosal surface facing upward & downward & kept moist with simulated intestinal fluid. Each tablet was placed in between the upper & lower platform in contact with the mucosa under a preload of 0.5 N for 60 seconds to allow adhesion. The motor was then started.  Upper probe was then lifted vertically as soon as water started collecting in other side of the device. The maximum detachment weight of water was recorded as the mucoadhesion force (N). Bioadhesive strength was expressed as force per unit contact area (N/cm²). Measurements were carried out in 3 replicates, and the mean ± SD values were reported.
Mucoadhesion retention time determination: In-vitro ‘wash-off’ test: It was conducted using in-house build mucoadhesion retention time determination device. The isolated chicken colon was used to test mucoadhesive tablets ex vivo.  After being cleaned, the colon was divided into equal sections, opened longitudinally, and placed on a tissue holder mucosal side up.  To simulate GI conditions, the holder was submerged in phosphate-buffered saline at 37 ± 0.5 °C with a steady saline flow.  The time it took for each pill to get wash off after being placed to the mucosa was measured as the mucoadhesion time.
 
            
(A)                                                             (B)
Fig. no. 2 (A) Mucoadhesion measurement device (B) Mucoadhesion retention time determination device
 
Optimization of trial batches based on Analysis of variance (ANOVA): To select optimized batch amongst trial batches ANOVA were carried out using Design Expert 13 software.
In-vitro drug release study: The in-vitro drug release study of the optimised batch of colon-targeted tablet was carried out using USP dissolution apparatus II (paddle type). The tablet was initially placed in 0.1 N HCl (pH 1.2) for 1 h, followed by phosphate buffer pH 6.8 for 3 h, and finally in phosphate buffer pH 7.4 to simulate colonic conditions, maintained at 37 ± 0.5 °C with a paddle speed of 50 rpm. At predetermined time intervals, samples were withdrawn, filtered, and analysed spectrophotometrically, replacing an equal volume of fresh medium to maintain sink conditions.
Anthelminthic Activity of optimized batch: The anthelminthic property of optimized tablet of Duranta Erecta was tested with equivalent concentration of Albendzole using Eisenia fetida (Indian earthworm) as the model organism.
RESULT AND DISCUSSION:
Determination of minimum concentration of Duranta erecta having anthelmintic activity: Duranta erecta extract showed dose-dependent anthelmintic activity, with increasing concentrations producing a marked decrease in paralysis and death times, while the control group showed no effect.
 
Table no. 2 Anthelmintic activity time of different concentrations of Duranta erecta
 
Concentration of extract (mg/ml)    Paralysis time (min)    Death time (min)
    1    2    3    Average    1    2    3    Average
2    142    172    159    157.6    170    191    184    181.6
5    31    38    40    36.3    42    53    58    114.3
10    16    15    13    14.6    22    26    17    53.66
50    7    4    6    5.6    9    8    9    8.6
100    1    2    4    2.3    3    2.5    7.5    4.3
Control group    No effect    No effect
 
Brine shrimp lethality assay (BSLA): The experimental dose was selected based on acute toxicity data, where the LD?? was found to be 140.9 mg. As per standard pharmacological practice, one-tenth of the LD?? value was considered a safe dose for further in-vivo evaluation. Accordingly, a dose of 10 mg was selected, which ensures pharmacological efficacy while minimizing the risk of toxic manifestations.
 
    Table no. 3 Observations of BSLA
Conc. of extract mg/ml    Total no. shrimps used/tube    Shrimp Survived    Total No. of Shrimp Survived    Percentage mortality (%)    LC50 (mg)
        1    2    3            
50    30    8    7    8    23    23.33    149.9
100    30    4    3    4    11    63.33    
200    30    2    3    1    6    80    
300    30    0    0    1    1    96.66    
 
Selection of excipients: The selection of excipients for the preparation of a mucoadhesive, colon-retentive herbal tablet is a critical step to ensure targeted drug delivery, prolonged residence time, and therapeutic efficacy. Excipients are chosen based on their biocompatibility, safety, and compatibility with the herbal extract depicted in table no. 1Heckel plot analysis was employed to evaluate the influence of binder concentration on the compression behavior of the formulated powder blends.

 
Table no. 4 Observations of Heckel plot parameters using 2% PVP K30 binder
Concentration of binder    compression pressure (Mpa)    Tablet Weight (g) w    Thickness (cm) h    Diameter (cm) d    Tablet Volume cm3 V=πr2h    Tablet Density (gm/cm3) ρtablet =V/W
True Density (gm/cm3)    Relative Density (D)=ρtablet / ρt    Heckel Term = In(1/1-D)    Slope (K)    Mean Yield Pressure (Py)= 1/K
2%    50    0.495    0.45    1    0.353    1.401    1.92    0.729    1.308    0.0084    119
    100    0.489    0.39    1    0.306    1.597    1.92    0.831    1.783        
    150    0.501    0.37    1    0.290    1.724    1.92    0.898    2.286        
    200    0.5    0.36    1    0.282    1.769    1.92    0.921    2.544        
 
 
Fig. no. 2 Compression Behavior of 2%PVP K30 (Heckel Plot)
 

 
Table No. 5 Observations of Py (Mpa) of 2%, 4% & 6% PVP K30
Binder Concentration (% w/w)    K (MPa?¹)    Py (MPa)    Compression Behavior
2%    0.0084    119    Poor plasticity
4%    0.0120    83    Optimal deformation
6%    0.0069    143    Over-binding
 
Heckel plot analysis demonstrated that 4% w/v PVP K-30 provided optimal plastic deformation behavior, as evidenced by the lowest mean yield pressure and improved densification characteristics.
Drug and excipient compatibility studies: done by FTIR: The extract of Durata erecta with major component Carbopol 934P & sodium alginate was found to be compatible by FTIR studies.
 
 
Fig. no. 3 FTIR spectrum of (A) Crude drug extract (B) Overlay of crude drug extract with sodium alginate (C) Overlay FTIR spectrum of crude drug extract with Carbopol 934 (D) Overlay FTIR spectrum of Carbopol 934 & sodium alginate
 
Analytical method development (UV spectrophotometer):
Construction of Calibration curve? Measured the absorbance (y-axis) of each solution of dilutions 10, 20, 40, 60, & 80 mcg/ml at the wavelength 283nm were plotted against absorption concentration on the x- axis. In the constructed calibration curve the relationship between concentration and absorbance was found to be linear. (R2 = 0.999)
 
Table no. 6 Results of Analytical method development (UV spectrophotometer)
Concentration
mcg/ml    Absorbance    Average    Standard Deviation ±    %RSD    Limit of Detection    Limit of Quantification
    1    2    3                    
10    0.072    0.069    0.071    0.071    0.001    2.161    0.027    0.082
20    0.14    0.142    0.144    0.142    0.002    1.408    0.035    0.107
40    0.272    0.273    0.274    0.273    0.001    0.366    0.017    0.053
60    0.42    0.419    0.418    0.419    0.001    0.238    0.017    0.053
80    0.568    0.564    0.56    0.564    0.004    0.709    0.071    0.215
 

 
 
Fig. no. 6 Calibration curve of dried extract of Duranta erecta
 
The developed UV spectroscopic method showed good linearity over the concentration range of 10–80 µg/mL, with absorbance increasing proportionally with concentration. The low SD and %RSD values (<2%) indicate excellent precision and repeatability of the method, which is within acceptable limits as per ICH Q2 (R1) guidelines. Additionally, the low LOD (0.027µg/mL) and LOQ (0.082µg/mL) values demonstrate high sensitivity. Overall, the method is simple, precise, and suitable for routine quantitative analysis.
FORMULATION DEVELOPMENT: Using Design of experiment 22 full factorial design formulations as per table no. 1 prepared for granulation by wet granulation process. 
Evaluation of granules: The granules were evaluated for bulk density, tapped density, true density, Carr’s index , angle of repose and Hausner’s ratio all parameters were within acceptable limits indicates, good flow ability and compressibility. These characteristics confirm the granules are suitable for tablet compression and uniformly during manufacturing. F1 batch shows required standards for effective performance. (Table no 7)
 
Table no. 7 Results of evaluation of prepared granules
TEST    F1    F2    F3    F4
Bulk density    0.556    0.545    0.486    0.360
Tapped density    0.598    0.617    0.690    0.732
True density(kg /m-3 )    991.3    982.1    955.2    876.3
Carr’s index (%)    8.33    12.90    14.65    18.65
Angle of repose (Degree)    26    32    38    45
Hausner’s ratio    1.10    1.09    1.15    1.22
 
Granule Size Distribution by Sieve Analysis: During granulation, excessive coarse granules cause Poor flow, Weight variation, Segregation. Adding a calculated amount of fines helps achieve an ideal particle size distribution (PSD), typically improving packing and compressibility. Size distribution curve of F1, F2 & F4 formulation granules were observed normal, but for F3 needed to adjust towards normal using formula
Fines to be added (g) = Target fines (g) − Existing fines (g)
  
Fig. no. 4 Observed size distribution of F3 formulation granules.
Correction of size distribution of F3 formulation granules:
Total granules = 100 g
Existing fines = 5% = 5 gm, Required fines = 15%
Step 1: Calculate target fines=15% of 100 =15gm
Step 2: Calculate fines to be added= 15gm −5gm = 10 g,
Hence added 10 gm of fines to correct the size distribution. Since batch weight increases; New batch weight=100 gm+10gm =110gm
  Fig. no. 5 Corrected size distribution of f3 formulation granules.
Tablet compression: Tablets were compressed using single punch compression machine & evaluated.
Enteric coating: The prepared tablet were coated with 10% Eudragit L100 & 10% PEG by dip coting method. 
 
Fig. no. 6 Prepared mucoadhesive herbal tablets of Duranta erecta for effective anthelmintic therapy

EVALUATION OF TABLETS:
 
Table no. 8 Evaluation of tablets (Physical parameters)
Parameters    Results
Size    Small
Color    Gray
Shape    Round
Odour    Pungent
Taste    Sweet
Table. No. 9 Evaluation of prepared tablets
Test    F1    F2    F3    F4
Thickness(mm)    3.06 ±0.11    2.80 ±0.5    2.76 ±0.5    2.70 ±0.15
Diameter (mm)    12.1 ±0.05    12 ±0.01    11.8 ±0.03    11.1 ±0.01
Hardness (kg/cm2 )    6.2 ±0.03    5.8 ±0.08    5.7 ±0.1    6.4 ±0.03
Friability (%)    0.65    0.57    0.45    0.52
Weight variation (mg)    Passed    Passed    Failed    Failed
Disintegration time (min.)    30    25    22    17
Mucoadhesion time (min.)    15    12.39    10.44    9.59
 
Optimization of formulation (ANOVA):  
Optimization of excipient concentration for mucoadhesion retention time: According to results of multiple linear regression analysis the Mucoadhesion retention time is strongly dependent on the X1 and X2 
Mucoadhesion retention time = +11.50 +1.00* X1 +2.00* X2 +0.50* X1* X2
The polynomial equation showed the co-efficient of both X1 and X2 possess positive. Therefore increasing values of X1 and X2 expected to increases the mucoadhesion retention time of prepared tablet. Both the factors has positive effects on mucoadhesion retention time individually also positive effect in combination. The coefficient value of X2 is greater than that of X1 indicates that sodium alginate has more effective in relation to mucoadhesion retention time than Carbopol 934P
Optimization of excipient concentration hardness of tablet: Based on the results of multiple linear regression analysis, Hardness of tablet is significantly influenced by both X1 and X2 & is represented by the following polynomial equation:
Hardness of tablet = +5.88 +0.52* X1 +0.87* X2
The results indicated that the coefficients of X1 and X2 are positive. This suggests that increasing the value of X1 & X2 expected to raise the hardness of tablet, Moreover, the higher coefficient value of X2 compared to X1 implies that sodium alginate has a more pronounced effect on the Hardness of tablet of than Carbopol 934. 
 
            
(A)                                                                            (B)
Fig no. 7 (A) Surface response curve of mucoadhesion retention time (B) Surface response curve of hardness of tablet
 
By selecting maximum mucoadhesion and hardness 6kg/cm2 Batch F1 was found to be optimized batch 
Dissolution study of optimized batch:

 
Table no. 10 Results of Dissolution study of optimized batch
pH of physiological fluid    Time (min)    Cumulative % drug release    pH of physiological fluid    Time (min)    Cumulative % drug release    pH of physiological fluid    Time (min)    Cumulative % drug release
1.2    5    0        6.8    150    15.11    ±1.2    7.2    330    64.11    ±1.2
    15    0            180    26.01    ±2.7        360    70.05    ±2.7
    30    0            210    39.09    ±1.6        390    75.23    ±1.6
    60    0            240    45.81    ±0.6        420    81.89    ±0.6
    90    0            270    50.53    ±0.9        450    90.92    ±0.9
    120    7.6    ±0.9        300    59.8    ±1.4        
 
 
Fig. no. 8 % Drug relese of optimized btch of mucoadhesive tablet formulation of Duranta erecta
 
In-vitro Anthelmintic activity: The optimized mucoadhesive tablet formulation showed significantly faster paralysis (14.6 min) and death times (53.6 min) compared to standard Albendazole 72.3 min & 86.6 min respectively at equivalent concentrations.

 
Table no. 11 Anthelmintic activity time of optimized batch of mucoadhesive tablet formulation of Duranta erecta compared with standard Albendzole
Concentration of extract (mg/ml)    Paralysis time (min)    Death time (min)
    1    2    3    Average    1    2    3    Average
Test optimized batch 10mg/ml    16    15    13    14.6    22    26    17    53.6
Sample Albendzole 10mg/ml    67    74    76    72.3    89    78    93    86.6
Control group    No effect    No effect
 

           
(A)                                                       (B)
Fig no. 9 Anthelmintic activity of (A) optimized batch of mucoadhesive tablet formulation of Duranta erecta compared (B) standard Albendzole
 
DISCUSSION: 
The methanolic extract of Duranta erecta exhibited a clear dose-dependent anthelmintic activity against Eisenia fetida, as evidenced by a progressive reduction in paralysis and death times with increasing extract concentration. Lower concentrations showed delayed effects, whereas higher concentrations (50–100 mg/mL) produced rapid paralysis and mortality, confirming the presence of potent anthelmintic phytoconstituents. These findings justified the selection of an effective yet safe dose for tablet formulation. The brine shrimp lethality assay indicated concentration-dependent cytotoxicity of the extract, with an LC?? value of approximately 140.9 mg/mL. The experimental dose was therefore selected well below the LC?? to ensure safety. The low mortality observed at selected concentrations confirms that the extract possesses acceptable safety margins, supporting its suitability for oral herbal formulation.Heckel plot analysis demonstrated that binder concentration significantly influenced the compression behavior of the powder blends. An initial decrease in mean yield pressure (Py) with increasing PVP K-30 concentration indicated improved plastic deformation and interparticle bonding. However, further increase in binder concentration resulted in increased Py, suggesting over-binding and reduced compressibility. The lowest Py observed at 4% PVP K-30 confirmed it as the optimum binder concentration for tablet formulation. FTIR spectra of the crude extract and polymer combinations showed no significant shifts, disappearance, or formation of new peaks, indicating the absence of chemical interactions between the drug and excipients. The retention of characteristic functional group peaks confirms compatibility and structural integrity of the extract within the formulation matrix. The developed UV spectrophotometric method showed excellent linearity in the concentration range of 10–80 µg/mL with a correlation coefficient (R² = 0.999). Low SD and %RSD values demonstrated high precision and repeatability, while low LOD and LOQ values confirmed good sensitivity. Hence, the method was considered suitable for routine quantitative analysis of the extract.  Granules from all batches exhibited acceptable bulk density, tapped density, Carr’s index, angle of repose, and Hausner’s ratio, indicating good flowability and compressibility. Among all batches, F1 demonstrated superior flow characteristics, which is essential for uniform die filling and consistent tablet weight during compression. Granule size distribution analysis revealed that most batches exhibited a normal distribution suitable for tablet compression. However, batch F3 required correction due to excessive fines. Adjustment of fines improved packing efficiency and compressibility, highlighting the importance of controlled particle size distribution in achieving uniform tablets.All formulated tablets showed acceptable appearance, uniform size, and consistent shape, indicating good manufacturing quality. Thickness and diameter values were within permissible limits, ensuring dose uniformity and reproducibility of the compression process. The hardness values of tablets were within the optimal range, providing adequate mechanical strength without compromising disintegration. Friability values below 1% indicated good resistance to abrasion and confirmed the mechanical integrity of tablets during handling and transportation. Formulations F1 and F2 complied with pharmacopoeial limits for weight variation, reflecting uniform granule flow and proper die filling. However, F3 and F4 failed the test, possibly due to poorer flow properties, emphasizing the influence of granule characteristics on tablet uniformity. Disintegration time decreased with increasing polymer concentration, indicating effective hydration and swelling behaviour of mucoadhesive polymers. The observed disintegration times were suitable for colon-targeted delivery, allowing sufficient time for gastric and intestinal transit before drug release. The mucoadhesion force increased with higher concentrations of mucoadhesive polymers, demonstrating stronger interaction between the tablet and intestinal mucosa. This enhanced adhesion is attributed to hydrogen bonding and polymer chain interpenetration with mucin, supporting prolonged colonic retention. The in-vitro wash-off test showed that formulations containing higher levels of Carbopol 934P and sodium alginate exhibited prolonged retention on the mucosal surface. ANOVA results confirmed a positive and significant effect of both polymers, with sodium alginate contributing more prominently to retention time.The optimized formulation exhibited negligible drug release in acidic and intestinal pH conditions, confirming effective enteric protection. Substantial and sustained drug release was observed at colonic pH, demonstrating successful colon targeting and controlled release behaviour of the formulation. The optimized mucoadhesive tablet exhibited a statistically significant reduction in paralysis and death times (14.6 min and 53.6 min, respectively) relative to the reference drug Albendazole (72.3 min and 86.6 min) at comparable concentrations. This enhanced activity may be attributed to prolonged drug release & mucosal contact and localized drug release, confirming the therapeutic potential of the developed colon-targeted herbal tablet.
CONCLUSION
The study successfully formulated colon-targeted mucoadhesive tablets of Duranta erecta with desirable pharmaceutical properties. The combination of Carbopol 934P and sodium alginate provided adequate mucoadhesion and tablet hardness, while the Eudragit enteric coating ensured targeted delivery. The innovative in vitro mucoadhesion retention time determination device provided accurate simulation of physiological conditions, validating the formulation's effectiveness. These findings indicate that Duranta erecta extract (10mg) mucoadhesive tablets are a promising herbal alternative for anthelmintic therapy, particularly in addressing drug resistance and minimizing systemic side effects. The approach improves patient compliance and demonstrates the viability of combining traditional herbal medicine with advanced drug delivery systems.
ACKNOWLEDGEMENT
Our sincere appreciation goes out to Dr. Shivajirao Kadam College of Pharmacy at Kasabe Digraj, Sangli and Dr. Patangrao Kadam College Sangli, for their assistance and materials during this study.  

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