Extraction and Purification Process of Lanolin from Sheep Wool and Industrial Washing Effluents

Abstract

Lanolin is a natural, complex wax produced by the sebaceous glands of wool-bearing sheep. It is widely utilized across the pharmaceutical, cosmetic, and industrial sectors due to its exceptional emollient, moisturizing, and protective properties. This study focuses on the extraction, purification, and characterization of lanolin derived from Algerian sheep wool. Extraction was performed using two distinct methods: a scouring and centrifugation technique as the primary approach, and a Soxhlet solvent extraction method using chloroform as a comparative reference, yielding 5.0% and 14.0% of crude lanolin, respectively. The subsequent purification of the crude product was carried out through a comprehensive four-stage process, involving acidification with phosphoric acid, neutralization with sodium hydroxide, washing with sodium chloride and hydro-alcoholic solutions, and a final drying step at 105°C. The purified lanolin was characterized based on its color, aspect, solubility, melting point, acid value, and saponification value. The physicochemical analysis revealed a melting point of 39°C, an acid value of 0.87 mg KOH/g, and a saponification value of 102.6 mg KOH/g. These results perfectly comply with the standard requirements established by the British Pharmacopoeia (BP 2023) for pharmaceutical-grade lanolin. Consequently, these findings clearly demonstrate that Algerian sheep wool represents a viable and high-quality source for pharmaceutical lanolin extraction, offering significant potential for industrial and agricultural exploitation in Algeria.