Document Type : Research Paper

Authors

• Marjan Daeihamed ¹
• Edris Mahdavi Fikjvar ²
• Sedigheh Naghipour ³
• Leila Mohtashami ⁴
• Maryam Haddadi ⁵
• Maryam Naseri ⁶

¹ Department of Pharmaceutics, School of Pharmacy, Guilan University of Medical Sciences, Rasht, Iran

² Medical Biotechnology Research Center, School of Paramedical Sciences, Guilan University of Medical Sciences, langrud, Iran

³ Student research committee, School of Pharmacy, Guilan University of Medical Sciences, Rasht, Iran

⁴ Department of Pharmacognosy, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran

⁵ Department of Pharmacognosy, School of Pharmacy, Guilan University of Medical Sciences, Rasht, Iran

⁶ Department of Traditional Pharmacy, School of Persian Medicine, Iran University of Medical Sciences, Tehran, Iran

Abstract

Background and Objective: Primula macrocalyx Bunge., a member of the Primulaceae family, grows in the highlands of Guilan Province, Iran. This plant has long been used in traditional medicine for the treatment of respiratory conditions such as pneumonia, bronchitis, and the common cold. However, to date, no medicinal product derived from this species has been developed in Iran. Therefore, the present study aimed to develop a liquid oral formulation of this plant and to evaluate the physicochemical properties of the prepared formulation.
Methodology: Following the collection of Primula macrocalyx in June 2020 from the Ulasbelangah region of Guilan Province, ethanolic extracts of the leaves, flowers, and roots were prepared using the maceration method. The plant materials were then analyzed for moisture content, total ash, and acid-insoluble ash. Qualitative phytochemical tests were conducted to identify major bioactive compounds, and the total phenolic and flavonoid contents of the extracts were quantified. During pre-formulation studies, the solubility of the extracts, as well as suitable dosage levels and excipients, were evaluated. Based on these findings, a syrup formulation was developed. The final formulation was subsequently assessed for its physicochemical and quality attributes, including appearance and organoleptic properties, pH, antimicrobial stability, sedimentation, and container closure integrity.
Results: The extraction efficiency of Primula macrocalyx (cowslip) was 19.04%, 25.17%, and 21.12% for flowers, leaves, and roots, respectively. Moisture content was 13% in the flowers and roots and 12% in the leaves. Total ash content was 6%, 11%, and 9.5% for flowers, leaves, and roots, respectively, while acid-insoluble ash values were 2%, 3.5%, and 3% for the same organs. Phytochemical screening revealed the presence of flavonoids, saponins, and tannins in the leaves; flavonoids and tannins in the flowers; and saponins and tannins in the roots. Total polyphenol content, expressed as gallic acid equivalents, was 41.44, 81.05, and 125.90 in roots, leaves, and flowers, respectively. Total flavonoid content, expressed as isoquercitrin equivalents, was 2.88 ± 0.081 in flowers and 2.26 ± 0.041 in leaves. The foaming index was 333 in leaves, 250 in roots, and less than 100 in flowers. Pre-formulation studies of the cowslip syrup evaluated extract solubility, optimal dosage, excipient selection, and a suitable formulation base. All extracts showed good solubility in water, while the addition of co-solvents such as propylene glycol and glycerin further enhanced solubility. The final syrup formulation met acceptable standards in terms of organoleptic properties, pH, viscosity, preservative efficacy, absence of sedimentation, and proper container closure performance.
Conclusion: Given the presence of bioactive compounds such as flavonoids and saponins in Primula macrocalyx, along with the favorable characteristics of the developed formulation, including acceptable organoleptic properties, suitable pH, appropriate flow behavior (viscosity), effective preservative performance, and absence of sedimentation, the prepared syrup can be proposed as a promising herbal product for the management of respiratory disorders.

Keywords

• common cowslip (Primula macrocalyx)
• oral liquid formulation
• saponins
• flavonoids

Main Subjects

• Phytochemistry (extraction, identification and measurement of active components)