Surface Solid Dispersion Technique for Solubility Enhancement of Nifedipine
Authors: Mhaske Ganesh S. , Neharkar Vishnu S , Deshmukh Amol S. , Awate Shyam S. , Satkar Shraddha S. , Gurav Mayuri V. , Ghatpande Kadambari S. , Panmand Priyanka A. 
Published: December 2024

Introduction:
Poor solubility is a common challenge in pharmaceuticals, hindering oral bioavailability. High throughput screening has led to an increase in
poorly soluble drug candidates. Enhancing solubility and dissolution rates is crucial for drug development. Various methods, including solid
dispersion, aim to improve solubility. A solid dispersion formulation process involves dispersing one or more active chemicals in a solid state
within an inert carrier or matrix. It can be made using solvent, melting, or melting-solvent procedures, among other techniques. By increasing the
surface area and dispersibility of poorly soluble pharmaceuticals, this method improves their solubility and rate of dissolution, ultimately leading to
an improvement in bioavailability.

Background:
Nifedipine solid dispersion emerged in the late 1970s to address its poor solubility and erratic bioavailability for cardiovascular treatment.
Researchers explored methods like fusion, solvent evaporation, and melt extrusion to enhance its solubility and dissolution rate. Over the years,
these efforts resulted in commercial products, highlighting the importance of solid dispersion in improving drug delivery and patient outcomes for
nifedipine therapy.

Aim:
The aim of this work is to use the surface solid dispersion approach to increase the solubility of nifedipine.

Objective:
The objective of the study is to develop surface solid dispersion formulations of nifedipine, evaluate their physicochemical properties, assess
solubility enhancement, analyze dissolution behavior and stability, and determine the potential of this technique to enhance the pharmaceutical
performance of nifedipine.

Materials and Methods:
Nifedipine was dissolved in the solvent-ethanol, and a carrier was then added at various drug-to-carrier ratios. The mixture was allowed to sit for
an hour before the solvent was evaporated on a water bath at 40-42ºC with occasional stirring. The resulting dried mass was pulverized, sieved, and
then dried further at 40ºC for 3 hours. For further study the powder was stored in desiccators.

Results:
Formulation S3 shows better increase in the solubility by solid dispersion technique, increases solubility from 0.002576 ± 0.00013 to 0.04379 ±
0.00013. Dissolution profile data found to be improved from 98.45 ± 0.41 to 99.57 ± 0.088%.

Conclusion:
This study explores the challenge of poor solubility in pharmaceutical formulation, focusing on Nifedipine. Surface solid dispersions (SSDs) are
investigated as a solution, with various polymers showing promise in enhancing solubility. SSDs, particularly with sodium starch glycolate (SSG)
as a carrier, significantly improve solubility, as confirmed by saturation solubility studies. Evaluation indicates SSD efficacy, with S3 emerging as
a promising formulation. This study underscores the potential of SSD technology in addressing solubility challenges and improving drug
bioavailability.